Radiology Dictionary

A

abdominal aorta

The portion of the largest artery in the body that runs through the stomach. It brings oxygenated blood to the abdominal and pelvic organs and the legs.
In simple terms: The main blood vessel in your belly that carries blood to your lower body.

abdominoperineal resection

Cancer cells in the anus, rectum and part of the large intestine are removed through the abdomen.
In simple terms: A surgery to remove cancer from the bottom part of the digestive tract.

abscess

A confined infection consisting of pus surrounded by inflamed tissue.
In simple terms: A painful, swollen lump filled with pus due to infection.

acetaminophen

A drug that reduces pain and fever but not inflammation.
In simple terms: A pain and fever reliever—like Tylenol®.

acute

Referring to the fast onset of a disease or condition.
In simple terms: Something that happens suddenly or quickly.

Adcetris® (brentuximab vedotin)

A treatment for Hodgkin lymphoma that mixes a chemotherapy drug with a monoclonal antibody that binds to specific parts on cancer cells.
In simple terms: A medicine used to treat certain types of cancer in the lymph glands.

adjuvant therapy

Treatment that adds to or complements the main therapy.
In simple terms: Extra treatment (like chemo or radiation) to help the main treatment work better.

adrenal glands

Small glands on top of each kidney. They make hormones important for metabolism, blood pressure, and stress response.
In simple terms: Hormone-making glands that help control stress and energy.

afterloaded implant

A brachytherapy treatment that delivers radiation directly to the tumor using a machine.
In simple terms: A device used to send radiation straight to a tumor.

allogeneic

A donor that is not the same person but is similar genetically (e.g., for a stem cell transplant).
In simple terms: Using someone else’s cells or tissue for treatment.

allograft

Tissue graft from a separate donor.
In simple terms: A transplant from another person.

Allopurinol

A drug that lowers uric acid levels in the blood, especially during cancer treatments.
In simple terms: Medicine that helps prevent gout or kidney problems during cancer treatment.

Alpha-1 antitrypsin (A1AT)

A protein that protects the lungs.
In simple terms: A natural substance in the body that helps shield the lungs.

Alpha-1 antitrypsin deficiency (A1AD)

A genetic illness where low A1AT levels can lead to lung disease.
In simple terms: A genetic condition that may cause lung problems like COPD.

alveoli

Tiny air sacs in the lungs that allow oxygen to enter the bloodstream and carbon dioxide to leave.
In simple terms: Tiny air pockets in the lungs that help you breathe.

amniocentesis

The suction of fluid from the amniotic sac using a needle inserted through the abdomen.
In simple terms: A test during pregnancy where fluid is taken from around the baby.

amniotic sac

A fluid-filled membrane within the abdomen that holds and protects the baby.
In simple terms: The “water bag” that surrounds the baby in the womb.

analgesic

A drug that relieves pain.
In simple terms: Painkiller.

androgen

A group of hormones (found more in men) that support male development. In women, they are converted to estrogens.
In simple terms: Male hormones like testosterone.

anemia

A condition where there are too few red blood cells, resulting in reduced oxygen delivery to tissues.
In simple terms: Low red blood cells—causes tiredness and weakness.

anesthesia

Drugs used to induce loss of sensation in preparation for surgery.
In simple terms: Medicine that makes you numb or unconscious during surgery.

anesthesiologist

A doctor specially trained to administer anesthesia safely.
In simple terms: The doctor who puts you to sleep or eases pain during surgery.

anesthetics

Drugs that create a loss of sensation for surgery.
In simple terms: Medicines that block pain or make you sleep during surgery.

aneurysm

A balloon-like bulge in a blood vessel caused by weakness in its wall. It may rupture and cause serious bleeding.
In simple terms: A weak spot in a blood vessel that can burst.

angina

Cramp-like chest pain due to limited blood flow to the heart.
In simple terms: Chest pain when the heart doesn’t get enough oxygen.

angiogenesis

Formation of new blood vessels.
In simple terms: The body growing new blood vessels.

angiogram

A test where dye is injected into the bloodstream and X-rays or CT/MRI scans are taken to show blood vessels.
In simple terms: A scan that shows if blood vessels are blocked.

angiography

An imaging exam using dye and X-ray/CT/MRI to view blood vessels.
In simple terms: A scan that lets doctors see blood flow in the body.

angioplasty

A procedure to open blocked blood vessels, often using a balloon or stent.
In simple terms: A treatment to unclog arteries.

annulus

The outer layer of the discs between spinal bones.
In simple terms: The outer ring of the spine’s cushions.

anterior fibromuscular stroma

The anterior (front) surface of the prostate.
In simple terms: The front part of the prostate gland.

antibiotics

Medications used to treat bacterial infections.
In simple terms: Medicine that kills bacteria.

antibodies

Substances that help fight toxins and bacteria in the body.
In simple terms: The body's natural defenders against germs.

anticoagulant therapy

The use of blood-thinning drugs to treat or prevent blood clots.
In simple terms: Treatment using blood thinners to stop clots from forming.

anticonvulsant

A drug used to prevent or reduce seizures.
In simple terms: Medicine that controls seizures.

anus

The opening at the end of the digestive tract where stool exits the body.
In simple terms: The body’s outlet for waste (where poop exits).

aortic aneurysm

A bulging area in the main artery of the body due to weakness.
In simple terms: A dangerous bulge in the body’s main blood vessel.

appendiceal lumen

The inside of the appendix where mucus travels to the large intestines.
In simple terms: The hollow tube inside the appendix.

appendicolith

A stone-like deposit in the appendix.
In simple terms: A hard lump inside the appendix that can trigger appendicitis.

appendix

A wormlike pouch located near the beginning of the large intestine. Its role is currently unclear.
In simple terms: A tiny organ near the large intestine—its purpose is uncertain.

arachnoid membrane

A thin membrane that covers the brain and spinal cord.
In simple terms: A protective layer around the brain and spine.

argon gas

A gas used in cryosurgery to freeze and destroy diseased tissue.
In simple terms: A very cold gas used to kill cancer cells.

arrhythmia

An abnormal heart rhythm.
In simple terms: An irregular heartbeat.

arteriovenous fistula

An abnormal connection between an artery and a vein.
In simple terms: A shortcut between a vein and artery—often made for dialysis treatment.

arteriovenous malformation (AVM)

An abnormal tangle of blood vessels that disrupts normal blood flow.
In simple terms: A faulty cluster of blood vessels—often in the brain or spine.

artery

Vessels that carry blood away from the heart.
In simple terms: Blood pipes that move blood from the heart to the body.

arthritis

Swelling and inflammation of a joint.
In simple terms: Painful, swollen joints.

artifact

In imaging, something that shows up that isn’t actually part of the body.
In simple terms: A mistake or glitch in an X-ray or scan.

asbestos

A group of minerals used in construction that can cause lung disease when inhaled.
In simple terms: A harmful building material that can damage lungs.

ascites

Fluid buildup in the abdomen causing swelling.
In simple terms: Belly swelling caused by trapped fluid.

aspirin

A drug that reduces pain, fever, inflammation, and blood clotting.
In simple terms: A common medicine for pain and to prevent clots.

asthma

A lung condition where airways narrow and produce excess mucus.
In simple terms: A condition that makes breathing hard and causes wheezing or coughing.

asymptomatic

Having no signs or symptoms of a disease.
In simple terms: Sick without feeling or looking sick.

atherectomy

A treatment using a catheter with a blade or laser to remove plaque from an artery.
In simple terms: A procedure to scrape out artery blockages.

atherosclerosis

Plaque buildup in arteries causing hardening and narrowing.
In simple terms: Clogged or hardened arteries.

atrophy

Wasting away or shrinking of tissues or organs.
In simple terms: Weakening or shrinking muscles/tissue.

audit

A record that tracks all user activity in a computer system.
In simple terms: A digital log that keeps track of who did what.

aura

Visual effects (like flashing lights or blurry vision) that may occur before a migraine headache.
In simple terms: Warning signs before a migraine—often visual disturbances.

authentication

Confirming someone’s identity in a computer system.
In simple terms: Proving who you are—like entering a password.

authorization

Controls that allow or prevent access to a system.
In simple terms: Permission levels that control access to information.

autoimmune disease

A disorder where the immune system attacks the body's own tissues.
In simple terms: When the body mistakenly attacks itself.

autologous

Using the same person as both donor and recipient in treatment.
In simple terms: Using your own cells or tissues for treatment.

axillary lymph node dissection

Surgical removal of lymph nodes in the armpit area during breast cancer treatment.
In simple terms: Surgery to check for cancer inside the armpit’s lymph nodes.

B

B cell

A type of white blood cell (lymphocyte) essential for the immune system. Non-Hodgkin B cell lymphoma begins in B cells.
In simple terms: A blood cell that helps fight infections. Some cancers start in these cells.

balloon angioplasty

A procedure where a balloon-tipped tube is put into a blocked blood vessel. The balloon is inflated to open the vessel, then removed.
In simple terms: A treatment to open clogged arteries using a tiny balloon.

balloon assistance

A vascular treatment technique using catheter-guided balloons to open narrowed blood vessels.
In simple terms: Using balloons inside blood vessels to help open them.

barium (Ba)

A natural metal used in barium sulfate as a contrast material for imaging the GI tract.
In simple terms: A substance used in medical scans to help doctors see the stomach and intestines.

barium sulfate

A radiopaque (x-ray blocking) powder used as a contrast material to make parts of the body easier to see on x-ray images.
In simple terms: A chalky liquid or powder patients swallow for clearer x-ray pictures of their stomach or intestines.

barium swallow (esophagram)

An x-ray test using barium sulfate to examine the pharynx and esophagus.
In simple terms: A test where you drink barium so doctors can see your throat and food pipe on an x-ray.

Barrett’s esophagus

A condition where cells in the esophagus change due to long-term acid reflux. Increases risk of cancer.
In simple terms: Damage from acid reflux that changes the throat lining and can lead to cancer.

baseline

The initial level.
In simple terms: The starting point or first measurement.

benign

Not cancerous; mild or non-dangerous condition.
In simple terms: Harmless or non-cancerous.

benign prostatic hyperplasia (BPH)

An enlarged prostate gland, common in older men.
In simple terms: A swollen prostate that makes urination difficult in older men.

beta blocker

Medicine used to lower blood pressure, treat chest pain, heart failure, and prevent heart attacks.
In simple terms: A drug that slows the heart and lowers blood pressure.

beta-amyloid plaque

Protein deposits in the brain linked to Alzheimer’s disease.
In simple terms: Clumps in the brain that may be related to Alzheimer’s.

Bexxar®

An iodine-131 medicine used in radioimmunotherapy to treat non-Hodgkin lymphoma.
In simple terms: A treatment that uses radiation to target certain types of blood cancer.

bile

A greenish-yellow fluid made by the liver, stored in the gallbladder, and used to digest fat.
In simple terms: A digestive fluid that breaks down fats and removes waste.

bile ducts

Tubes that carry bile from the liver to the gallbladder and small intestine.
In simple terms: Pathways that move bile where it’s needed for digestion.

biliary atresia

A birth condition where bile ducts are blocked.
In simple terms: Babies are born with blocked bile ducts, causing liver problems.

biliary system / biliary tract

Includes the gallbladder and ducts through the liver that carry bile into the bowel to digest fat.
In simple terms: The system that stores and moves bile to help digest food.

biologic therapy (biotherapy)

Treatment that uses natural or lab-made substances to boost the body’s defenses against cancer.
In simple terms: Therapy that helps the immune system fight cancer.

biometrics

A unique identifier like a fingerprint or voice sample used to verify identity.
In simple terms: Using your fingerprint or face to unlock a device.

biopsy

Taking a tissue sample for diagnosis.

The sample taken.
In simple terms: Removing a small piece of tissue to check for disease (like cancer).

bladder

A balloon-like organ that stores urine before it leaves the body.
In simple terms: The body’s storage bag for urine.

bleeding disorder

A condition where blood doesn’t clot properly.
In simple terms: The body has trouble stopping bleeding.

blood clot

A thickened mass of blood.
In simple terms: A gel-like lump that stops bleeding—but can be dangerous if it blocks blood flow.

blood coagulation / blood clotting

Process where blood changes from liquid to semi-solid to stop bleeding.
In simple terms: How blood thickens to stop a cut from bleeding.

blood thinning agents (blood thinners)

Medicine used to prevent blood clots from forming or growing.
In simple terms: Drugs that make blood flow more freely and prevent clots.

bone marrow

Soft tissue inside bones where blood cells are made.
In simple terms: The factory inside bones that makes new blood cells.

bone scan

An imaging test using a radioactive tracer to detect bone problems.
In simple terms: A scan that shows bone issues like fractures, infections, or cancer.

bore

The center opening of the MRI machine where a person lies for scanning.
In simple terms: The tunnel you go into for an MRI scan.

bowel

Part of the digestive system after the stomach, including the small and large intestines.
In simple terms: The intestines—where food is digested and waste leaves the body.

brachytherapy (internal radiation)

Radiation therapy where radioactive material is placed directly inside the body to treat cancer.
In simple terms: Putting tiny radioactive seeds or pellets inside the body to kill cancer.

brain mapping

A study using electrodes to find important brain areas to avoid during surgery.
In simple terms: A way to locate brain areas before surgery so they aren't damaged.

brainstem

The base of the brain that connects to the spinal cord.
In simple terms: The bottom part of the brain that controls vital functions like breathing.

BRCA1 and BRCA2

Genes that help prevent cancer. Mutations increase breast and ovarian cancer risk.
In simple terms: Genes that, when damaged, can raise the chance of breast or ovarian cancer.

breast density

Refers to how much tissue versus fat is in the breast. Dense tissue makes cancer harder to spot on mammograms.
In simple terms: When breasts have more tissue and less fat, making cancer harder to detect.

bronchi

Large air passages that lead from the windpipe to the lungs.
In simple terms: Main air tubes that carry air into the lungs.

bronchial tubes

Tubes that deliver air from the windpipe into the lungs.
In simple terms: The pathways your breath travels into your lungs.

bronchiectasis

Widening of the breathing tubes, often from infection—may require surgery.
In simple terms: Damaged airways in the lungs that cause mucus buildup and breathing problems.

bronchitis

Swelling of the air tubes leading to/from the lungs.
In simple terms: An irritated airway that causes coughing and trouble breathing.

bronchoscope

A tool used to look inside the windpipe and bronchi.
In simple terms: A camera used to inspect the airways.

bronchoscopy

A procedure to look inside the airways using a bronchoscope.
In simple terms: A test where a tube with a camera goes into the lungs to check for problems.

bruit

An abnormal sound heard through a stethoscope over blood vessels.
In simple terms: A swishing sound that may mean a blood vessel is narrowed.

Budd-Chiari syndrome

A blockage of veins that carry blood from the liver back to the heart.
In simple terms: A liver condition caused by blocked veins.

bulla (pl. bullae)

A thin-walled air pocket in the lung—often seen in people with emphysema.
In simple terms: A large air bubble in the lung.

bursa (pl. bursae)

A fluid-filled sac that reduces friction between bones and tendons.
In simple terms: A cushion between bones and muscles to prevent rubbing.

C

C-11 PIB

Carbon-11-labeled Pittsburgh Compound B used in PET scans to detect beta-amyloid plaques in the brain, which are linked to Alzheimer’s disease.
Layman’s term: A special tracer used in brain scans to look for signs of Alzheimer’s.

CA-125

A blood test that measures protein levels often found in higher amounts in tumor cells.
In simple terms: A blood test used to help detect certain cancers, especially ovarian cancer.

calcification

The hardening of body tissues due to buildup of calcium and other substances.
In simple terms: When parts of the body become stiff or hardened because of calcium deposits.

calcium score

A number that shows how much calcium is in the walls of the heart’s arteries (from a CT scan).
In simple terms: A measure of heart disease risk based on calcium build-up in arteries.

cancer

Any type of malignant growth that invades tissues, can spread, and may return after treatment.
In simple terms: A disease where cells grow uncontrollably and can spread through the body.

carcinoembryonic antigen

A protein found in developing babies and certain cancers in adults.
In simple terms: A marker that can indicate cancer when found at high levels in adults.

cardiac pacemaker

An electrical device that keeps the heart beating at a normal rhythm.
In simple terms: A small device that helps control abnormal heartbeats.

C-arm

An x-ray image intensifier.
Layman’s term: A machine shaped like a “C” used during surgery to take live x-ray images.

carotid artery

One of two major arteries in the neck that supply blood to the brain.
In simple terms: The main blood vessels in your neck that bring blood to your brain.

carotid endarterectomy

A surgery to remove plaque buildup from the carotid arteries.
In simple terms: A procedure to clear blocked neck arteries to help prevent stroke.

CAT scan

See computed tomography (CT).
In simple terms: A detailed x-ray scan that shows inside the body.

cataracts

Clouding of the eye’s lens that affects vision.
In simple terms: A condition where the eye lens becomes cloudy, causing blurry vision.

catheter

A tube used to drain fluids, give medicine, or access internal areas.
In simple terms: A flexible tube placed in the body to remove fluid or deliver treatment.

catheter angiography

An exam of blood vessels using contrast dye injected through a catheter.
In simple terms: A scan that shows blood vessels using dye delivered through a tube.

catheter-directed thrombolysis

A procedure that uses a catheter to deliver medicine or devices that break up blood clots.
In simple terms: A treatment that uses a tube to dissolve dangerous blood clots in vessels.

cauterize

Using heat (usually from a laser) to destroy tissue or seal blood vessels to prevent infection.
In simple terms: Burning tissue to stop bleeding or prevent infection.

cecum

A pouch where the small intestine connects to the large intestine.
In simple terms: The first part of the large intestine.

cephalometric

Relating to measurement of the head.
In simple terms: Measuring the size or shape of the head and face.

cerebral

Relating to the brain.
In simple terms: Having to do with the brain.

cerebrospinal fluid

Fluid that surrounds and protects the brain and spinal cord.
In simple terms: The protective fluid cushioning the brain and spine.

cervical

Refers to the neck region of the spine OR the cervix (lower part of uterus).
In simple terms: Can mean neck-related or relating to the female cervix.

cervix

The lower part of the uterus that connects to the vagina.
In simple terms: The opening between the uterus and vagina.

chemotherapy

Treatment of disease using chemical substances, usually related to cancer.
In simple terms: Drugs used to kill cancer cells.

cholesterol

A compound in body tissues; high levels in blood can lead to artery disease.
In simple terms: Fat-like substance in blood—too much can clog arteries.

chronic obstructive pulmonary disease (COPD)

A long-term lung disease (e.g., emphysema, bronchitis) that makes breathing difficult.
In simple terms: A serious lung condition that causes long-term breathing problems.

claudication

Leg pain and cramping during walking that stops when resting.
In simple terms: Leg pain from poor blood flow—usually when walking.

claustrophobic

Fear of being in small or enclosed spaces.
In simple terms: Scared of tight or closed places.

clopidogrel (Plavix®)

An antiplatelet drug that prevents harmful blood clots, lowering risk of stroke or heart attack.
In simple terms: A medicine that prevents clots and protects the heart.

closed bone biopsy (needle bone biopsy)

A procedure where a needle removes a small bone sample for testing.
In simple terms: Taking a bone sample using a needle to check for disease.

clot

To turn from liquid to thick or semi-solid form.
In simple terms: When blood thickens (like a gel) to stop bleeding.

clubbing

Enlargement of fingertip areas, often seen in advanced lung disease.
In simple terms: Swollen, rounded fingertips—may signal lung problems.

CNS prophylaxis

Chemotherapy or radiation to protect the central nervous system from cancer, often via lumbar puncture.
In simple terms: Treatment to prevent cancer from spreading to the brain or spinal cord.

coagulate

To change from liquid to thick or solid, like blood clotting.
In simple terms: Blood thickening to stop bleeding.

colon

The first 5–6 feet of the large intestine, part of the digestive system.
In simple terms: The long part of the large intestine where stool forms.

colon adenoma

A potentially precancerous polyp that grows on the inner wall of the colon.
In simple terms: A growth in the colon that may turn into cancer if untreated.

colonoscope

A long flexible tube with a camera used during colonoscopy.
In simple terms: A camera tube used to look inside the colon.

colonoscopy

A visual exam of the colon using a lighted flexible instrument through the rectum.
In simple terms: A procedure to look inside the colon to check for problems or polyps.

color Doppler

An ultrasound that uses color to show the speed and direction of blood flow.
In simple terms: A scan that shows how blood moves through vessels.

colorectal cancer

Cancer in the colon or rectum—the lower digestive tract.
In simple terms: Cancer in the large intestine or rectum.

colostomy

Creation of a new opening in the colon to divert waste outside the body.
In simple terms: A surgery that creates a “new exit” for stool through the abdomen.

compression therapy

Wearing tight garments to reduce swelling and prevent vascular issues.
In simple terms: Using tight clothing/sleeves to control swelling or improve blood flow.

computed tomography (CT)

A scan that combines x-rays and computers to create detailed images of the body, including bones and organs.
In simple terms: A 3D x-ray scan that shows inside the body very clearly.

CT angiography

A CT scan of blood vessels using contrast dye.
In simple terms: A CT scan that shows blood flow and blockages.

computer-aided detection (CAD)

Software used to highlight suspicious areas in images for radiologists.
In simple terms: A computer tool that helps doctors spot possible problems in scans.

concussion

A mild brain injury caused by impact, where the brain hits the inside of the skull.
In simple terms: A head injury that can cause dizziness, headaches, or confusion.

conformal radiation therapy

Uses CT imaging to shape the radiation beam to match the exact tumor size and shape.
In simple terms: A precise form of radiation that targets only the tumor.

congenital

Present at birth.
In simple terms: Something you’re born with.

congestive heart failure

A condition where the heart cannot pump blood well enough, causing fluid buildup in tissues.
In simple terms: Weakened heart that causes fluid to build up—making breathing difficult.

constipation

Sparse or difficult bowel movements.
In simple terms: Trouble pooping or infrequent stools.

contrast material

Substances used in imaging to make body parts easier to see. Examples include barium, iodine solutions, saline, or air.
In simple terms: Dye or fluid used in scans to help doctors see organs better.

contusion

A bruise caused when blood leaks into tissue from trauma.
In simple terms: A bruise.

core needle biopsy

A biopsy using a large hollow needle to collect tissue samples from an abnormal growth.
In simple terms: A needle procedure to take tissue for testing.

coronary arteries

Arteries that carry oxygen-rich blood to the heart.
In simple terms: Blood vessels that feed the heart.

coronary artery bypass graft surgery

A surgery to improve blood flow by redirecting blood around blocked heart arteries.
In simple terms: Heart surgery that creates a detour around clogged arteries.

coronary artery disease

Narrowing of the heart’s arteries.
In simple terms: Blocked or narrowed arteries that reduce blood to the heart.

coronary bypass surgery

Surgical rerouting of blood in the heart’s arteries to bypass blockages.
In simple terms: A “detour” surgery for blood flow in the heart.

Cowden syndrome

A disorder causing non-cancerous growths and raising cancer risk.
In simple terms: A genetic condition that causes abnormal growths and increases cancer risk.

cranial

Relating to the skull.
In simple terms: Related to the head bones.

craniofacial

Related to the face and skull.
In simple terms: Involving both the head and face.

Crohn’s disease

A long-term inflammatory bowel disease affecting mainly the small intestine.
In simple terms: A serious digestive disease that causes pain, diarrhea, and weight loss.

cryoprobe

A tool that applies extreme cold to specific body areas.
In simple terms: A device that freezes tissue—often used to kill cancer cells.

CT colonography (virtual colonoscopy)

CT scan that creates detailed images of the colon and rectum.
In simple terms: A colon exam using a CT scan instead of a camera tube.

CT enteroclysis

A special CT scan of the small bowel using contrast through a tube.
In simple terms: A CT scan to see the small intestine clearly.

cyanosis

Blue coloring of the lips, skin, or nails due to low oxygen in the blood.
In simple terms: Blue skin or lips because of low oxygen levels.

cyclotron

A particle accelerator used to create radiation for cancer treatment and imaging.
In simple terms: A machine that makes medical radiation used in scans or treatments.

cystic fibrosis

An inherited disease causing mucus buildup in the lungs, intestines, and pancreas.
In simple terms: A genetic condition where thick mucus makes breathing and digestion difficult.

cystoscopy

A procedure using a camera on a tube to view the inside of the bladder.
In simple terms: A camera test to see inside the bladder.

cysts

Abnormal sacs filled with gas, liquid, or semi-solid material.
In simple terms: Fluid-filled lumps or sacs in the body.

D

data integrity

Making sure information isn’t changed during transfer and arrives exactly as it was sent.
In simple terms: Keeping data accurate and unchanged when it’s sent from one place to another.

deep vein thrombosis

A blood clot forms in a major vein that returns blood to the heart and lungs. It can block the vein or break loose and travel to the lungs.
In simple terms: A dangerous blood clot in a deep vein, often in the leg, that can travel to the lungs.

defibrillator (ICD)

A pacemaker-like device that monitors heart rhythm and delivers lifesaving shocks if needed.
In simple terms: A device implanted in the chest that shocks the heart if it starts beating dangerously.

definitive treatment

Primary treatment that aims to fully cure a disease.
In simple terms: The main treatment meant to completely get rid of an illness.

delivery device

In cancer brachytherapy, the tool used to place radioactive material into a tumor area (e.g., catheter or small applicator).
In simple terms: A tool used to deliver radiation directly to cancer inside the body.

densitometry

A method used to measure the density of tissues.
In simple terms: Scanning to see how dense bones or body tissues are.

density

Thickness or mass.
In simple terms: How solid or heavy something is for its size.

deoxyribonucleic acid (DNA)

Acid found in cell nuclei that carries hereditary information.
In simple terms: The genetic code that determines how your body is built.

diabetes (diabetes mellitus)

A disease where the body has trouble using sugar because of lack of insulin. It can lead to high blood sugar and long-term complications.
In simple terms: A disorder where the body can't control blood sugar properly.

diagnostic ultrasound

Uses sound waves to produce images of internal body structures for diagnosis.
In simple terms: A scan that uses sound waves to see inside the body.

dialysis

A method of removing waste from the body when kidneys don’t work properly.
In simple terms: A treatment that cleans the blood when the kidneys can’t.

diaphragm

A muscular sheet that separates the chest and abdomen.
In simple terms: The main breathing muscle located under the lungs.

diaphragmatic hiatus

An abnormal opening in the diaphragm.
In simple terms: A hole in the diaphragm where it shouldn’t be.

diarrhea

Frequent loose or watery bowel movements.
In simple terms: Watery or frequent poop.

dietitians

Specialists who help patients maintain good nutrition before, during, and after treatment.
In simple terms: Professionals who help people eat properly for health or treatment.

diffusion tensor imaging (DTI)

A special type of MRI that shows pathways of nerve fibers in the brain using water molecule movement.
In simple terms: A scan that shows brain nerve connections in color to detect damage.

digestive system

The body system that breaks down food, absorbs nutrients, and removes waste.
In simple terms: The organs that process food and get rid of waste.

digestive tract

The long tube that runs from the mouth to the anus, part of the digestive system.
In simple terms: The path food takes through the body from eating to pooping.

digital rectal exam

A test of the lower rectum and prostate (in men) using a gloved finger.
In simple terms: A check where the doctor uses a finger to examine the rectum or prostate.

dilation and curettage (D&C)

A procedure where the inner lining of the uterus is scraped to remove contents.
In simple terms: A surgical procedure to clear tissue from the uterus.

dilator

A tool or substance used to widen an opening or structure.
In simple terms: A device used to make a body passage bigger.

dissection

A tear in a blood vessel wall where blood flows into the layers and worsens the tear.
In simple terms: A serious tear in an artery that can spread and block blood flow.

diverticulum

A pouch that forms in the bowel wall, often in the colon.
In simple terms: A small “bubble” or pocket in the intestine.

Doppler ultrasound

Uses ultrasound to detect moving blood and measure speed/direction. Widely used to view blood flow in real time.
In simple terms: An ultrasound that shows how blood flows through vessels.

dosimetrists

Experts who calculate radiation doses to treat cancer while protecting healthy tissue.
In simple terms: Specialists who plan how much radiation to use for cancer treatment safely.

double-contrast barium enema (DCBE)

A test where barium and air are placed in the colon, and x-rays are taken of the colon and rectum.
In simple terms: A special x-ray test of the colon using barium and air to show details.

drug-eluting stent

A metal tube placed in an artery to keep it open, slowly releasing medicine to prevent scar tissue.
In simple terms: A stent that keeps arteries open AND releases medicine to prevent clots.

ductal carcinoma in situ (DCIS)

Early-stage breast cancer that is limited to the milk ducts and has not spread.
In simple terms: A very early breast cancer that stays inside the ducts and is treatable.

duodenum

The first part of the small intestine below the stomach.
In simple terms: The first section of the small intestine where digestion continues.

dura mater

The outermost protective membrane around the brain and spinal cord—thick and tough.
In simple terms: A strong protective layer covering the brain and spine.

dysphagia

Difficulty swallowing.
In simple terms: Trouble swallowing food or liquids.

E

echocardiogram

This test uses a small transducer that produces high-frequency sound waves, which create detailed images of the heart.
In simple terms: An ultrasound scan of the heart that shows how it looks and how it’s beating.

ectopic pregnancy

A pregnancy in which the fetus develops outside the uterus. It instead develops in a fallopian tube.
In simple terms: A pregnancy growing in the wrong place (usually the tube), not in the womb.

edema

An accumulation of an excessive amount of fluid in cells and tissues.
In simple terms: Swelling caused by extra fluid in the body.

electrocardiogram (EKG / ECG)

A test that records the electrical activity of the heart. It is used to help diagnose certain heart abnormalities.
In simple terms: A heart tracing that shows how the heart’s electricity and rhythm are working.

electronic detector

The part of a digital imaging system that captures and converts x-rays as they pass through a patient into digital signals, which are sent to a computer to make images.
In simple terms: The “sensor” that catches x-rays and turns them into a digital picture.

electronic medical information

Patient information and history that is saved on electronic media. Layman’s term: Medical records stored on a computer instead of paper. electronic medical record (EMR) / electronic health record A computer system that stores patients’ medical information and lets providers view it on a computer.
In simple terms: A digital chart doctors see on a screen with all your medical history.

embolic agent

A material used to block off blood flow through a vessel.
In simple terms: A substance doctors use to purposely plug a blood vessel.

embolic stroke (cerebral embolism)

This type of stroke occurs when a blood clot formed elsewhere breaks away and travels to a blood vessel in the brain, blocking blood flow.
In simple terms: A stroke caused by a clot that travels to the brain and blocks blood flow.

embolism

A blood clot that breaks loose, travels through the bloodstream and lodges in an organ or artery, partially or completely blocking blood flow.
In simple terms: A traveling clot that gets stuck in a vessel and blocks blood flow.

embolization

Movement of a clot from its origin until it lodges in a vessel, cutting off blood flow. Catheter embolization is when doctors deliberately insert material to block a vessel to stop bleeding or blood flow.
In simple terms: When a clot or added material moves and plugs a vessel, stopping blood flow.

embolus (pl. emboli)

A plug made of a detached clot or other material that completely or partially blocks a vessel.
In simple terms: The actual clot or object that blocks the blood vessel.

embryo

In humans, the developing organism from conception until about the end of the second month. After that, it is called a fetus.
In simple terms: The early stage of a baby’s development in the womb (first 2 months).

emphysema

A common type of COPD where air sac linings in the lungs are damaged and air gets trapped. The lungs enlarge and lose elasticity, making it hard to exhale.
In simple terms: A lung disease where damaged air sacs make it hard to breathe out.

empyema

An abscess or infection in the space between the lung and chest wall (pleural space).
In simple terms: Pus-filled infection in the space around the lungs.

encephalitis

An acute inflammation of the brain caused by a viral infection.
In simple terms: Brain swelling due to a virus.

encephalopathy

An alteration of normal brain function that can lead to confusion.
In simple terms: Brain problem that causes confusion or changes in thinking.

encryption

Transforming information to make it unreadable as a security measure. Only someone with the key can read it.
In simple terms: Locking data with a secret code so only people with the key can see it.

endocrine gland

A gland that produces hormones into the blood or lymph. An organ made of special cells that release hormones into the bloodstream to affect many body processes.
In simple terms: A hormone-making organ (like the thyroid or pancreas) that sends signals through the blood.

endoluminal

Referring to the inside.
In simple terms: Inside the hollow part of a tube or organ.

endometrial ablation

A treatment for abnormal vaginal bleeding where the uterine lining (endometrium) is destroyed.
In simple terms: A procedure to remove or burn the lining of the uterus to reduce heavy bleeding.

endometrial biopsy

A procedure in which a sample of tissue from the uterine lining is removed and examined for abnormal cells.
In simple terms: Taking a small tissue sample from the uterus lining to check for disease.

endometrium

The mucous membrane forming the inner layer of the uterine wall; its thickness changes with the menstrual cycle.
In simple terms: The inner lining of the uterus that thickens and sheds each month.

endorectal coil

A wire coil inserted through a small tube into the rectum during MRI to get detailed images of the prostate or nearby structures.
In simple terms: A special MRI device placed in the rectum to get clearer pictures of the prostate.

endorectal MRI

An MRI performed from inside the rectum.
In simple terms: An MRI scan done using a probe placed in the rectum for detailed images.

endoscope

An optical tool used to examine inside the body.
In simple terms: A thin tube with a camera and light used to look inside organs.

endoscopic mucosal resection

A procedure using an endoscope to remove early-stage cancer from the esophagus.
In simple terms: Removing early esophagus cancer through a tube passed down the throat.

endoscopic retrograde cholangiopancreatography (ERCP)

An endoscope is passed through the mouth to the small intestine, contrast is injected, and x-rays are taken to examine the bile duct, liver, gallbladder, and pancreas.
In simple terms: A camera-and-dye test to look at the bile ducts, gallbladder, liver, and pancreas.

endoscopic treatments

Treatments that use an endoscope to reach and treat internal areas.
In simple terms: Procedures done through a flexible tube with a camera, instead of open surgery.

endoscopy

The use of an endoscope to see the inside of the body and organs.
In simple terms: Looking inside the body with a camera tube.

endovaginal

Within the female genital canal from uterus to vulva.
In simple terms: Inside the vagina.

endovascular surgery

A procedure to repair an abdominal aortic aneurysm. A stent graft attached to a catheter is inserted through a leg artery, placed inside the aneurysm, and held with hooks.
In simple terms: A minimally invasive surgery done from inside blood vessels to fix a bulge in the main belly artery.

enema

Preparation involving injection of liquid into the intestine through the rectum, often to clear the bowel or deliver medicine.
In simple terms: Liquid put into the rectum to clean out the bowels or give medication.

enzyme

A protein that controls chemical reactions in the body.
In simple terms: A helper protein that speeds up chemical processes in the body.

epididymis

A long, tightly coiled tube behind each testicle that collects sperm.
In simple terms: The storage and transport tube for sperm behind the testicle.

epididymitis

Swelling of the epididymis.
In simple terms: Inflammation or infection of the sperm-carrying tube behind the testicle.

epidural analgesia

Injection of local anesthetic into the epidural space of the spine to prevent or relieve pelvic pain.
In simple terms: Pain relief injection given in the lower back around the spine (often used in labor).

epidural hematoma

May be in the skull or spine. In the skull: bleeding between the skull and dura mater; can compress the brain and be fatal if not treated quickly. In the spine: blood fills the space between the spinal column and outer lining of the spinal cord.
In simple terms: A dangerous blood collection between the skull and brain covering, or around the spinal cord.

esophagectomy

Surgery to remove part of the diseased esophagus and nearby lymph nodes. The remaining esophagus is reconnected to the stomach with a tube or part of the GI tract.
In simple terms: Surgery to take out part of the food pipe and reconnect it to the stomach.

esophagitis

Swelling of the esophagus, the tube connecting throat and stomach.
In simple terms: Inflammation or irritation of the food pipe, often causing pain when swallowing.

esophagogastrectomy

Surgery removing part of the esophagus, nearby lymph nodes, and part of the stomach, then reconnecting with a tube or GI tract segment.
In simple terms: Surgery that removes part of the food pipe and stomach and then rebuilds the connection.

esophagoscope

A long, narrow tube with a light and lens used to examine the throat and esophagus.
In simple terms: A scope (camera tube) used to look inside the food pipe.

esophagram (barium swallow)

An x-ray exam using barium contrast to check the pharynx and esophagus in the upper GI tract.
In simple terms: A test where you swallow barium so x-rays can show your throat and food pipe.

esophagus

The “food tube” that connects the mouth to the stomach.
In simple terms: The tube that carries food from your throat to your stomach.

excisional biopsy

A surgical biopsy where the entire abnormal area and some surrounding normal tissue are removed.
In simple terms: Cutting out the whole lump or suspicious area to test it.

exercise cardiac stress test

A test where you walk or bike while heart rate, rhythm, blood pressure and electrical activity are monitored to see if the heart gets enough blood during stress.
In simple terms: A treadmill or bike test to see how well your heart works when it’s working hard.

external beam therapy (external radiation therapy)

Highly focused beams of high-energy x-rays are aimed at the tumor to destroy cancer cells while sparing nearby normal tissue.
In simple terms: Radiation treatment that comes from a machine outside the body to kill cancer cells.

F

fallopian tube

One of the two tubes extending from the uterus to the ovaries. It provides a path for the egg to travel from the ovary to the uterus during ovulation.
In simple terms: The tube that carries the egg from the ovary to the womb.

false negative test result

A test result that indicates a disease is not present, when in fact it is present.
In simple terms: A test that wrongly says you’re healthy when you actually have the condition.

false positive test result

A test result that indicates cancer or disease is present when it actually is not.
In simple terms: A test that incorrectly says you’re sick when you’re not.

fecal immunochemical test (FIT)

A test that checks for hidden (invisible) blood in stool.
In simple terms: A stool test to look for blood that you can’t see.

fecal occult blood test (FOBT)

A test that checks for hidden blood in stool.
In simple terms: Another stool test to find unseen blood—may suggest bleeding in the digestive tract.

femoral artery

A major artery that supplies blood to the lower body.
In simple terms: The large artery in the thigh that carries blood to the legs.

fetus

In humans, the developing baby from the end of the eighth week of pregnancy until birth.
In simple terms: What an unborn baby is called after 2 months until birth.

fibroadenoma

A benign (non-cancerous) breast tumor.
In simple terms: A harmless lump in the breast—common in younger women.

fibrocartilaginous

Composed of fibrocartilage—connective fibers found between tendons, ligaments, or bones.
In simple terms: Made of tough, flexible tissue found between bones and ligaments.

fibrocystic

A common non-cancerous condition involving cysts in the breast, causing lumpiness and sometimes pain.
In simple terms: Lumpy breast tissue that’s usually harmless but may feel tender.

fibroid

Resembling or made of fibrous tissue.
In simple terms: Made of thick, stringy tissue.

fibroid tumor (myoma)

Masses of muscle and fiber tissue in the wall of the uterus.
In simple terms: Non-cancerous growths in the uterus—can cause pain or heavy periods.

fiducial marker

A tiny metal object (often gold) placed near a tumor to help guide radiation therapy accurately.
In simple terms: A small marker placed in the body to help aim radiation at a tumor.

fine needle aspiration

A type of biopsy where a thin needle is used to collect a small sample of cells for testing.
In simple terms: Using a thin needle to take a tiny tissue sample for diagnosis.

fissure

A groove or tear.
In simple terms: A small crack or split in tissue, often painful.

fistula

An abnormal or false connection between organs or blood vessels.
In simple terms: A tunnel or opening between body parts that shouldn’t be connected.

fluoroscope

A device that shows x-ray images in real time on a screen.
In simple terms: A machine that gives moving x-ray pictures, like a live video.

fluoroscopy

A real-time x-ray exam using a fluoroscope to see deep structures in the body.
In simple terms: A live x-ray video that lets doctors watch what’s happening inside.

Foley catheter

A flexible tube inserted into the bladder to allow continuous urine drainage.
In simple terms: A tube placed in the bladder to help drain urine when someone can’t urinate normally.

fontanelle (soft spot)

The gap between skull bones in a fetus or infant.
In simple terms: The soft spot on a baby’s head before the skull fully forms.

fractionation

Giving radiation treatment in smaller doses over time instead of one large dose, to reduce tissue damage.
In simple terms: Spreading radiation therapy into several small sessions to protect healthy tissue.

fracture

A partial or complete break in a bone.
In simple terms: A broken bone.

G

gadolinium

An element used in contrast media for magnetic resonance imaging (MRI).
In simple terms: A special dye used during MRI scans so organs and blood vessels show up more clearly.

gallbladder

A pear-shaped organ under the liver that stores bile, which helps digest fat.
In simple terms: A small storage organ under the liver that holds fluid to help digest fatty foods.

gamma camera

A camera that records radiation coming from a radioactive chemical that collects in a certain organ or tissue.
In simple terms: A special camera doctors use to track how radioactive medicine moves inside the body.

Gamma Knife

A radiation therapy machine using focused gamma rays to treat brain tumors and abnormalities.
In simple terms: A highly accurate machine that treats brain problems with concentrated radiation instead of surgery.

gamma radiation (gamma rays)

Very high-frequency radiation that can damage or destroy body cells.
In simple terms: Powerful radiation that can kill cancer cells—but may also harm healthy cells.

gantry

The part of a CT or radiation machine that holds the x-ray tube and detectors and rotates around the patient.
In simple terms: The large ring in a CT or radiation machine that moves around your body during imaging or treatment.

gastroesophageal junction

The point where the esophagus connects to the stomach.
In simple terms: The spot where the food pipe meets the stomach.

gastroesophageal reflux disease (GERD)

A condition where stomach acid flows into the esophagus. Causes heartburn and can increase cancer risk if untreated.
In simple terms: Acid reflux that causes heartburn—when stomach acid comes back up the throat.

gastrointestinal (GI)

Related to the stomach and intestines.
In simple terms: Anything involving digestion—from the stomach to the intestines.

gastropathy

A disease or condition affecting the stomach.
In simple terms: Any problem or illness involving the stomach.

gene therapy

Treatment that involves changing a person’s genetic material.
In simple terms: Medical treatment that tries to fix or replace faulty genes.

general anesthesia

Drugs used to make a patient completely unconscious during surgery.
In simple terms: Medicine that puts you to sleep so you don’t feel anything during surgery.

gland

A group of cells that produces and releases needed substances in the body (like hormones or sweat).
In simple terms: A body part that makes important fluids—like hormones, saliva, or sweat.

glandular

Related to glands.
In simple terms: Involving the parts of the body that make hormones or fluids.

glenoid labrum

A rim of cartilage attached to the shoulder blade that helps stabilize the arm bone. A common injury area.
In simple terms: A cushion around the shoulder joint that helps the arm stay in place—often gets torn in athletes.

glial cells

Cells that support and protect nerve cells in the brain and spinal cord.
In simple terms: Helper cells in the brain that support neurons.

glioma

A type of brain or spinal cord tumor that starts in glial cells.
In simple terms: A brain or spinal tumor that starts in the cells that support nerves.

Glucophage® (Metformin)

A diabetes medication that helps the body respond to insulin and control blood sugar.
In simple terms: A common diabetes medicine that lowers blood sugar and helps insulin work better.

glucose

A sugar that is the body’s main energy source.
In simple terms: Blood sugar—what the body uses for fuel.

graft

Tissue or organ used for transplantation.

To transplant tissue.

Artificial vessel used in dialysis.
In simple terms: Tissue or tubing placed in the body—often during surgery—to fix or replace something.

grand mal seizure (tonic–clonic seizure)

A seizure involving violent shaking and loss of consciousness.
In simple terms: A major seizure where a person loses consciousness and shakes uncontrollably.

Graves’ disease (hyperthyroidism)

A condition where the thyroid makes too much hormone, causing fast heartbeat, weight loss, and high blood pressure.
In simple terms: An overactive thyroid that speeds up the body’s functions too much.

great saphenous vein

The longest vein in the body, running from the foot up the inner thigh to the groin.
In simple terms: A long leg vein often used for heart bypass surgery.

guide wire

A thin wire used to guide catheter placement during minimally invasive procedures.
In simple terms: A thin wire doctors use to steer medical tools inside the body.

Guillain-Barré syndrome

An autoimmune disorder that causes severe nerve damage, often leading to weakness or paralysis.
In simple terms: A rare condition where the immune system attacks nerves, sometimes causing paralysis.

H

hematoma

A collection of blood formed when small blood vessels are damaged and leak into nearby tissues.
In simple terms: A bruise or pocket of blood under the skin caused by injury.

hemodialysis

A procedure for people whose kidneys cannot remove waste from the blood. It cleans the blood and returns it to the body.
In simple terms: A treatment that acts like an artificial kidney to clean the blood.

hemoglobin

The iron-rich protein inside red blood cells that carries oxygen and gives blood its red color.
In simple terms: The oxygen-carrying part of red blood cells.

hemoptysis

Coughing up blood from the airways.
In simple terms: Spitting or coughing up blood from the lungs.

hemorrhagic stroke

A stroke caused by a blood vessel in the brain bursting and interrupting blood flow.
In simple terms: A brain bleed that stops oxygen from reaching brain tissue.

hemothorax

Excess blood in the chest cavity (pleural space), often from injury or disease.
In simple terms: Blood buildup around the lungs.

heparin

A medication that thins the blood and helps prevent clots.
In simple terms: A blood thinner used to stop clots from forming.

hepatic steatosis

A buildup of fat in the liver.
In simple terms: Fatty liver disease.

hepatic vein

Three veins (right, middle, left) that carry blood from the liver back to the heart.
In simple terms: Veins that drain blood from the liver to the heart.

hepatobiliary system

Includes the liver, gallbladder, and bile ducts, which make, store, and release bile to help digest fat and remove waste.
In simple terms: The body’s system that processes fats and handles waste through the liver and gallbladder.

hepatocellular carcinoma / hepatoma

The most common type of primary liver cancer that starts in the liver cells.
In simple terms: The main type of liver cancer that begins in liver tissue.

hereditary diffuse gastric cancer

A genetic condition that causes a high risk of stomach cancer.
In simple terms: An inherited disorder that greatly increases chances of stomach cancer.

herniated disk

A bulging or damaged spinal disk that can press on nerves and cause pain.
In simple terms: A slipped or ruptured disk in the spine that may pinch nerves.

high-dose rate (HDR) brachytherapy

Temporary radiation therapy that delivers strong radiation bursts directly to the tumor for a few minutes at a time.
In simple terms: A fast form of radiation treatment given directly to a tumor.

hives

Red, itchy, swollen spots on the skin caused by an allergic reaction.
In simple terms: Raised, itchy skin welts from an allergic response.

Hodgkin lymphoma (HL)

One of two main types of lymphoma (blood cancer affecting white blood cells in the immune system).
In simple terms: A cancer of the lymph system that affects certain white blood cells.

hormone

A chemical made by the body that controls the activity of organs and cells.
In simple terms: A messenger chemical that tells parts of the body what to do.

hospice

A system of care focusing on comfort and quality of life for terminally ill patients.
In simple terms: End-of-life care that helps patients live comfortably, not cure illness.

human immunodeficiency virus (HIV)

A virus spread through body fluids that attacks the immune system and may lead to AIDS.
In simple terms: A virus that weakens immunity and can progress to AIDS if untreated.

human papilloma virus (HPV)

A group of viruses spread through sexual contact; the most common sexually transmitted infection.
In simple terms: A very common sexually transmitted virus that can sometimes cause cancer or warts.

hydrocephalus

A condition where fluid builds up in the brain, causing pressure, enlarged head (in babies), and possible brain damage.
In simple terms: “Water on the brain” — excess fluid causing swelling and pressure.

hypercalcemia

High levels of calcium in the blood, often due to overactive parathyroid glands or genetic causes.
In simple terms: Too much calcium in the blood — can cause nausea, confusion, or kidney issues.

hyperparathyroidism

Excessive hormone production by the parathyroid glands.
In simple terms: Overactive glands in the neck that raise calcium levels too much.

hyperthyroidism (Graves’ disease)

Thyroid makes too much hormone—causing fast heartbeat, high blood pressure, and weight loss.
In simple terms: An overactive thyroid that speeds up the body.

hypoattenuating

On an imaging scan, an area that looks darker than surrounding tissue.
In simple terms: A darker spot on a scan, often signaling abnormal tissue.

hypothyroidism

The thyroid doesn’t make enough hormone—causing weight gain, tiredness, and dry skin.
In simple terms: An underactive thyroid that slows down the body.

hysterectomy

Surgical removal of the uterus.
In simple terms: Surgery to remove the womb.

hysterosalpingography

An x-ray exam of the uterus and fallopian tubes using contrast material.
In simple terms: A dye-based x-ray test to check if the uterus and fallopian tubes are open.

hysteroscope

A narrow lighted tube used to examine the inside of the uterus.
In simple terms: A tiny camera tool used to look inside the uterus.

hysteroscopy

A procedure using a hysteroscope to visually examine the uterus through the vagina.
In simple terms: A camera procedure to see inside the womb.

I

ibuprofen

A non-steroidal anti-inflammatory drug (NSAID) available over-the-counter.
In simple terms: A common pain and fever reliever (like Advil® or Motrin®); also helps reduce swelling.

ileostomy

A procedure that connects the ileum (end of the small intestine) to an opening in the abdomen.
In simple terms: Surgery that reroutes bowel waste to exit through an opening in the belly instead of the rectum.

ileum

The third and final section of the small intestine.
In simple terms: The last part of the small intestine where nutrients are absorbed.

image recording plate

Part of a digital x-ray system that captures radiation and converts it into images using a computer.
In simple terms: A plate in an x-ray machine that records the image before it's sent to a computer.

image-guided biopsy

Using imaging (like ultrasound or CT) to help target a small or hidden lesion for biopsy.
In simple terms: A biopsy where imaging helps guide the needle to the right spot.

immunotherapy

Giving small amounts of allergens to build resistance. Or, using the body’s immune system to fight cancer.
In simple terms: Treatments that boost or train the immune system—either against allergies or cancer.

impaction

A trapped tooth that cannot fully emerge. Or, a hard stool stuck in the rectum that cannot pass normally.
In simple terms: A stuck tooth—or severe constipation where stool becomes blocked.

impingement

Painful condition where shoulder tendons or bursa become inflamed, causing weakness and limited movement.
In simple terms: Shoulder pain from pinched or irritated tissue—common in athletes.

implant

Material inserted or grafted into the body (for teeth, joints, or tissue).
In simple terms: A medical device or material placed inside the body—like metal joints or tooth implants.

implanted port

A small disk inserted under the skin and connected to a vein to deliver medication or draw blood.
In simple terms: A small device placed under the skin to make getting IVs and treatments easier.

impotence

Inability to maintain an erection and engage in sexual activity.
In simple terms: Troubles with achieving or keeping an erection.

incentive spirometer

A breathing device that helps patients inflate their lungs and prevent pneumonia after surgery.
In simple terms: A lung exercise tool used to help patients breathe deeply after surgery.

incidental finding

Something discovered during an exam that wasn’t being looked for.
In simple terms: An unexpected finding on a scan or test.

incontinence

Inability to control the release of urine or feces.
In simple terms: Accidental leaking of urine or stool.

indolent

Slow to develop or progress.
In simple terms: Slow-growing or not aggressive.

infarction

Tissue death caused by lack of blood and oxygen.
In simple terms: Damage or death of tissue, often seen in heart attacks.

inferior vena cava

A large vein that carries blood from the legs and abdomen back to the heart.
In simple terms: The main vein that returns blood to the heart from the lower body.

inferior vena cava (IVC) filter

A device placed in the inferior vena cava to stop blood clots from reaching the lungs or heart.
In simple terms: A small trap placed in a major vein to catch clots before they can cause a stroke or lung problem.

inflammation

The body’s protective response to injury or irritation—redness, heat, swelling, and pain.
In simple terms: Swelling or irritation that happens when the body is healing or reacting to damage.

inflammatory bowel disease (IBD)

A group of conditions causing chronic inflammation in the intestines, including Crohn’s and ulcerative colitis.
In simple terms: Long-term inflammation of the digestive tract causing pain, diarrhea, and flare-ups.

interferon

A drug used in biologic therapy that slows cancer cell growth.
In simple terms: Medicine that helps the immune system slow down cancer.

internal jugular vein

One of the major veins in the neck that carries blood from the brain and face to the heart.
In simple terms: A large neck vein that drains blood from the brain.

internal radiation therapy

See brachytherapy.
In simple terms: Radiation given from inside the body directly to the tumor.

interstitial lung disease

A disorder causing scarring and shortness of breath in lung tissue. May lead to respiratory or heart failure.
In simple terms: Lung disease that causes scarring and makes breathing harder over time.

interstitium

The supportive tissue in the lungs that holds tiny air sacs (alveoli).
In simple terms: The structure or “framework” around the lung’s air sacs.

interventional radiologist

A doctor who uses imaging (fluoroscopy, CT, ultrasound) to guide minimally invasive procedures such as biopsies or drainage.
In simple terms: A specialist who uses imaging to do procedures without open surgery.

interventional radiology

The medical field that performs minimally invasive procedures using imaging guidance.
In simple terms: Using imaging to perform treatments through tiny cuts instead of surgery.

intervertebral disks

Fibrous pads between spinal bones that act as cushions.
In simple terms: The soft “shock absorbers” between the bones of the spine.

intima

One of the inner layers of artery walls, including the carotid arteries.
In simple terms: The smooth inner lining of blood vessels.

intracranial

Inside the skull.
In simple terms: Located within the head or brain area.

intracranial pressure (ICP)

Pressure inside the skull, including brain tissue and fluid.
In simple terms: The pressure inside the head—too much can be dangerous.

intractable ascites

Fluid buildup in the abdominal cavity that continues even after treatment.
In simple terms: Severe belly fluid buildup that doesn’t go away with standard treatment.

intraoral

Inside the mouth.
In simple terms: Within the mouth.

intraperitoneal therapy

Anti-cancer drugs delivered directly into the abdominal cavity via a port under the skin.
In simple terms: Cancer treatment where medication is delivered straight into the belly area.

intrauterine

In the uterus.
In simple terms: Inside the womb.

intravenous

Inside a vein; used to deliver fluids or medicine through a needle.
In simple terms: When medicine goes directly into a vein through an IV.

intravenous pyelography (IVP)

An x-ray exam of kidneys, ureters, and bladder after injecting contrast into a vein.
In simple terms: A dye-based x-ray test that shows how the kidneys and bladder are working.

invasive

A procedure requiring surgical incision or deeper access to organs.
In simple terms: A medical procedure that involves cutting into the body.

involved site radiation

Radiation therapy focused only on areas known to have cancer.
In simple terms: Targeted radiation only to the cancerous area.

iodine

A trace element found in salt and sea-based foods; used in contrast imaging tests.
In simple terms: A mineral needed by the body and used in imaging dyes.

ionizing radiation

Radiation with enough energy to alter cells and DNA.
In simple terms: Strong radiation that can change or damage cells (used in imaging and cancer treatment).

irradiation

Exposure to electromagnetic radiation such as light, heat, or x-rays.
In simple terms: Exposure to radiation—sometimes used for treatment or imaging.

irritable bowel syndrome (IBS)

A digestive disorder causing stomach pain and irregular bowel movements (constipation and/or diarrhea).
In simple terms: Stomach condition with cramps and unpredictable bowel movements.

ischemia

Lack of enough blood supply to a body part or organ.
In simple terms: When part of the body isn’t getting enough blood or oxygen.

ischemic stroke

A stroke caused by a blocked or narrowed blood vessel supplying the brain.
In simple terms: A stroke from a clot or blockage that stops blood flow to the brain.

isotope

Versions of the same chemical element that have different atomic masses. Many are used in medical imaging.
In simple terms: A type of the same element that weighs differently—often used in scans.

J

jaundice

A condition caused by high levels of bilirubin (a yellow/orange pigment), which turns the skin and eyes yellow.
In simple terms: Yellowing of the skin and eyes, often due to liver problems.

jejunum

The middle part of the small intestine.
In simple terms: The section of the small intestine between the duodenum and ileum.

K

kidney

One of two bean-shaped organs that filter blood and produce urine.
In simple terms: Organs that clean the blood and make urine.

L

laceration

A torn wound or deep cut.
In simple terms: A cut or tear in the skin or tissue.

laparoscope

A thin tube with a light and lens used to look inside the abdomen.
In simple terms: A camera tool used to see inside the belly during surgery.

laparoscopy

A procedure using a laparoscope to view organs inside the abdomen through a small incision.
In simple terms: A minimally invasive surgery using a camera inserted through a small cut.

laparotomy

A surgery that involves making a large cut in the abdomen to examine the organs.
In simple terms: Open surgery to look inside the abdomen.

large intestine

The final part of the digestive system where water is absorbed, and waste is prepared to leave the body.
In simple terms: The colon — where waste turns into stool before leaving the body.

laser

A device that produces a focused beam of light strong enough to cut or destroy tissue.
In simple terms: A powerful light tool used in surgery to cut or remove tissue.

lateral view

A side view.
In simple terms: A picture or scan taken from the side.

laxative

A substance that helps move the bowels.
In simple terms: Medicine that helps you poop.

lesion

An abnormal area of tissue caused by injury or disease — can be cancerous or noncancerous.
In simple terms: A spot or damaged area in the body that shouldn’t be there.

lethal-ice

Water frozen at -40°C or lower, which kills cells.
In simple terms: Extremely cold ice used to destroy tissue, often in medical treatments.

leukemia

A cancer of blood-forming cells in the bone marrow.
In simple terms: Blood cancer that starts in the bone marrow.

Li-Fraumeni syndrome

A rare inherited condition that greatly increases cancer risk.
In simple terms: A genetic disorder that makes people more likely to develop many types of cancer.

linear accelerator (LINAC)

A machine used in radiation therapy to direct high-energy beams at tumors.
In simple terms: A device that delivers precise radiation to treat cancer.

liquid nitrogen

Extremely cold nitrogen used to freeze and destroy abnormal tissue.
In simple terms: Very cold liquid used to freeze off diseased tissue.

liver

The largest gland in the body, involved in metabolism and bile production.
In simple terms: Organ that filters blood, helps digestion, and processes nutrients.

lobules

Milk-producing glands in the breast.
In simple terms: Small structures in the breast that make breast milk.

local anesthesia

Medication that numbs a small area without putting the patient to sleep.
In simple terms: Numbing medicine used so you don’t feel pain in one spot.

local anesthetic

Medication used to produce local numbness — can be injected, applied as a cream, or a patch.
In simple terms: Medicine that numbs the skin or area being treated.

localization

Identifying and limiting something to a specific area — such as a tumor.
In simple terms: Finding an exact spot in the body (like locating a tumor).

low dose rate (LDR) brachytherapy

A cancer treatment that places a radioactive material near a tumor for several hours at a time.
In simple terms: Low-dose internal radiation therapy used over a longer time.

low-dose computed tomography (LDCT)

CT scan using less radiation than a standard CT.
In simple terms: A safer version of a CT scan that uses lower radiation.

lumbar

Refers to the lower back (spine bones L1–L5).
In simple terms: Lower back area of the spine.

lumbar puncture (spinal tap)

A test that removes fluid from the lower spine using a needle.
In simple terms: A needle procedure to collect spinal fluid from the lower back.

lumen (pl. lumina/lumens)

The inside space of a tube-like structure, such as a blood vessel or intestine.
In simple terms: The hollow part inside a tube—like the inside of a blood vessel.

lumpectomy

Surgical removal of a lump, usually from the breast.
In simple terms: Surgery to remove a breast lump without removing the whole breast.

lung

Organs that allow the body to breathe and exchange oxygen and carbon dioxide.
In simple terms: Organs that help you breathe.

lung volume reduction surgery

Removal of damaged lung tissue to allow healthier tissue to work better.
In simple terms: Surgery to remove diseased parts of the lung to make breathing easier.

lymph

A clear fluid containing white blood cells that circulates through the lymphatic system.
In simple terms: Body fluid that helps fight infections.

lymph nodes

Small structures that filter lymph and store immune cells.
In simple terms: “Filter stations” that trap germs and swollen during infection.

Lymphadenopathy

Swollen lymph nodes.
In simple terms: Swollen glands.

lymphangiography

An older x-ray test of the lymph system (now replaced by lymphoscintigraphy).
In simple terms: An older imaging test of the lymph system.

lymphatic malformation

Misshaped lymph vessels that trap fluid and form cysts.
In simple terms: A fluid-filled lump caused by abnormal lymph vessels.

lymphatic system

Network of vessels and lymph nodes that move infection-fighting cells through the body.
In simple terms: The body’s infection-fighting drainage system.

lymphedema

Swelling (usually in the arms or legs) caused by poor lymph drainage.
In simple terms: Fluid buildup that causes swelling due to blocked lymph flow.

lymphocytes

White blood cells that help fight infection—includes B cells and T cells.
In simple terms: Immune system cells that protect against disease.

lymphoma

Cancer of lymphocytes (a type of white blood cell). Includes Hodgkin and non-Hodgkin types.
In simple terms: Cancer of the immune system.

lymphoscintigraphy

Imaging test that shows lymph flow using nuclear medicine.
In simple terms: A scan to see how lymph fluid moves in the body.

M

magnetic resonance angiography (MRA)

A scan that uses magnetic fields—rather than x-rays—to create images of blood vessels.
In simple terms: A type of MRI used to see blood vessels without using radiation.

magnetic resonance imaging (MRI)

An imaging test that uses radio waves and a strong magnet to take detailed pictures inside the body.
In simple terms: A scan that uses magnets—not x-rays—to get clear images of organs and tissues.

malignant

Cancerous cells that can spread and damage other tissues.
In simple terms: Cancer that can grow and spread.

mammography

A breast x-ray used to detect disease, especially cancer.
In simple terms: A breast screening test to look for cancer.

mandible

The lower jawbone.
In simple terms: Lower jaw.

margin (surgical margin)

A small area of healthy tissue removed along with a tumor during surgery.
In simple terms: Extra tissue removed around a tumor to make sure all cancer is gone.

maxilla

The upper jawbone.
In simple terms: Upper jaw.

media

An inner layer of artery walls.
In simple terms: A layer inside major blood vessels.

mediastinum

Central chest area between the lungs, containing the heart, major blood vessels, trachea, and esophagus.
In simple terms: The space in the middle of the chest behind the breastbone.

medical radiation physicists

Experts who help plan and safely deliver radiation treatment for cancer.
In simple terms: Specialists who make sure radiation therapy is accurate and safe.

melanoma

A serious type of skin cancer that develops from pigmented spots.
In simple terms: A dangerous skin cancer.

membrane

A thin layer of tissue that covers, protects, or separates parts of the body.
In simple terms: A thin tissue layer acting like a lining or barrier.

meninges

Thin protective layers that surround the brain and spinal cord.
In simple terms: The coverings around the brain and spine.

meningitis

Inflammation of the meninges, usually caused by infection.
In simple terms: A serious infection of the brain and spinal cord lining.

menopause

The time when a woman stops having menstrual periods.
In simple terms: The end of a woman’s monthly periods.

menstrual cycle

Monthly cycle when the uterus prepares for pregnancy; if no pregnancy occurs, the lining is shed.
In simple terms: A woman’s monthly reproductive cycle.

menstruation

Shedding of the uterine lining—commonly called a period.
In simple terms: Monthly bleeding from the uterus.

mesentery

Membrane that attaches the intestines to the abdominal wall.
In simple terms: Tissue that holds the intestines in place.

metabolic rate

The amount of energy the body uses in a certain time.
In simple terms: How fast the body burns energy.

metabolism

All chemical processes in the body, including energy use, digestion, and waste removal.
In simple terms: How the body processes food and uses energy.

metastases

Spread of disease—especially cancer—to another area of the body.
In simple terms: When cancer spreads to other parts of the body.

metastasize

To spread from one part of the body to another.
In simple terms: When cancer moves to a new location.

metastatic tumor

A new tumor formed when cancer spreads to another body part.
In simple terms: Cancer that has spread and formed a new tumor.

microstent

A tiny tube-like mesh that keeps an artery open after angioplasty.
In simple terms: A small tube placed in a blood vessel to keep it open.

midline catheter

A 4–6 inch catheter placed in a large vein for several weeks to give medicine or take blood.
In simple terms: A long-lasting IV tube used for ongoing treatment.

migraine headache

A severe headache often with nausea, vomiting, light sensitivity, and sometimes visual disturbances (aura).
In simple terms: A strong headache that can cause nausea and sensitivity to light and sound.

mild cognitive impairment (MCI)

Memory or thinking issues that are worse than normal aging but do not affect daily life.
In simple terms: Early memory problems—not yet dementia.

mild traumatic brain injury

See concussion.
In simple terms: A mild form of brain injury from a hit or fall.

milk ducts

Tubes in the breast that carry breast milk to the nipple.
In simple terms: Pathways that carry breast milk.

mini stroke

See Transient Ischemic Attack (TIA).
In simple terms: A brief stroke that goes away but warns of real risk.

minimal and moderate sedation

See sedation, minimal and moderate.
In simple terms: Medicine that relaxes you but does not fully put you to sleep.

minimally invasive

A procedure using small incisions or punctures rather than open surgery.
In simple terms: Surgery done through small cuts, not big ones.

modality

The method used to diagnose or treat a disease.
In simple terms: The type of medical test or treatment used.

monoclonal antibodies

Lab-made molecules that attach to cancer cells to help target them.
In simple terms: Artificial antibodies designed to find and attack cancer cells.

monoclonal antibody therapy (targeted therapy)

Uses monoclonal antibodies combined with drugs or radiation to attack cancer cells directly.
In simple terms: Treatment that delivers cancer-killing medicine straight to the tumor.

MR spectroscopy (MRS)

A type of MRI that measures brain chemicals to detect disease.
In simple terms: An MRI that shows chemical changes in the brain.

mucous

A slippery fluid made by membranes to protect and lubricate body surfaces.
In simple terms: Body mucus that protects tissues.

multi-detector computed tomography (MDCT)

A type of CT scan that produces very detailed images quickly using multiple detectors.
In simple terms: A faster, clearer version of a CT scan.

multiple myeloma

A rare cancer of white blood cells in the bone marrow.
In simple terms: Bone marrow cancer affecting blood cells.

multiple sclerosis

A disease that damages nerve coverings in the brain and spinal cord.
In simple terms: A disorder where the immune system damages nerves, causing weakness and problems with movement.

musculoskeletal

Relating to muscles and bones.
In simple terms: Having to do with muscles and the skeleton.

myelogram

An x-ray of the spine after injecting contrast material.
In simple terms: A spinal imaging test using dye.

myelography

A radiographic procedure that examines the spinal cord using contrast material.
In simple terms: A scan that helps find spinal cord problems using dye.

myeloma

A tumor of bone marrow; the cancer form is multiple myeloma.
In simple terms: A cancer that starts in bone marrow.

myocardial infarction (heart attack)

Occurs when blood flow to the heart is blocked and part of the heart begins to die.
In simple terms: A heart attack.

myocardial perfusion scan

A nuclear medicine test that shows blood flow to the heart muscles.
In simple terms: A scan to see how well blood reaches your heart.

myomas (fibroid tumors)

Noncancerous tumors in the uterus that can cause pain or heavy bleeding.
In simple terms: Uterine fibroids.

myomectomy

Surgical removal of uterine fibroids.
In simple terms: Surgery to remove fibroids but keep the uterus.

myometrium

The muscular layer of the uterus.
In simple terms: The muscle wall of the uterus.

myopathy

A disease causing weakness and loss of muscle tissue.
In simple terms: A muscle disorder that leads to weakness.

N

narcotic

A substance used medically to relieve pain and/or cause drowsiness or sleep.
In simple terms: Strong pain-relief medication that can make you sleepy.

nasal cavity

A system of air channels connecting the nose with the back of the throat.
In simple terms: The inside of the nose where air passes through to the throat.

necrosis

The death of living tissue.
In simple terms: When tissue dies, often due to injury or lack of blood flow.

needle aspiration

Using a fine needle to remove cells or fluid from an area for testing.
In simple terms: A needle procedure to take a sample of fluid or cells.

needle biopsy

The removal of cells or tissue using a small needle for diagnosis.
In simple terms: Using a needle to collect tissue for testing (often to check for cancer).

needle electrode

A wire that carries electrical current to create heat, destroy tissue, seal blood vessels, or monitor electrical activity.
In simple terms: A needle tool used to burn tissue or measure electric signals in the body.

neoadjuvant treatment

Treatment given before the main treatment.
In simple terms: A therapy used before the primary treatment to shrink a tumor.

neonatal intensive care unit (NICU)

A specialized hospital unit for critically ill or premature newborns.
In simple terms: Intensive care for sick or premature babies.

neoplasm

Abnormal tissue growth that forms a mass; may be benign or cancerous.
In simple terms: An abnormal lump or tumor.

nephrogenic systemic fibrosis

A rare reaction in people with kidney disease who receive MRI contrast—causes thickening of skin and organs.
In simple terms: A rare complication after MRI contrast that can harden skin and tissues.

nephropathy

Damage or disease of the kidneys.
In simple terms: Kidney disease.

nerve cell (neuron)

A specialized cell that sends and receives electrical signals in the brain and nervous system.
In simple terms: The basic cell that carries messages in the nervous system.

nerve fibers (axons)

Threadlike extensions from nerve cells that carry electrical impulses.
In simple terms: The long “wires” that carry nerve signals.

neuroendovascular treatments

Procedures using tiny instruments or catheters inserted into brain blood vessels to treat abnormalities.
In simple terms: Minimally invasive brain procedures done through blood vessels.

neurofibrillary tangles

Abnormal structures found in neurons; a hallmark of Alzheimer’s disease.
In simple terms: Brain cell tangles linked to Alzheimer’s.

neurologic

Related to the nervous system and its disorders.
In simple terms: Involving the brain, spine, or nerves.

neuron

See nerve cell.
In simple terms: A nerve cell that sends signals in the brain and body.

neuroradiology

A specialty that uses imaging to diagnose disorders of the brain, head, and neck.
In simple terms: Medical imaging focused on the brain and nervous system.

neurostimulators

Implanted devices that stimulate nerves to block pain signals or improve organ function.
In simple terms: Devices placed in the body to reduce pain by sending electrical signals to nerves.

nodule

A small solid lump, which may be benign or cancerous.
In simple terms: A small bump or lump in the body.

non-Hodgkin lymphoma

A type of blood cancer that begins in immune system cells (B cells or T cells).
In simple terms: A cancer of the lymphatic system (not Hodgkin type).

noninvasive

A procedure that does not require surgery or insertion of tools into the body.
In simple terms: A test or treatment that doesn’t involve cutting or instruments inside the body.

nonradiologic

Not related to radiology or imaging.
In simple terms: Not involving medical imaging.

nonrepudiation

A security feature ensuring that messages or actions cannot be denied.
In simple terms: Proof that a message was definitely sent and received (often using digital signatures).

NSAID

A non-steroidal anti-inflammatory drug (e.g., ibuprofen, aspirin) that reduces pain and swelling.
In simple terms: Common pain and swelling medicine like ibuprofen or Advil.

nuclear medicine

A specialty using radioactive substances to diagnose or treat diseases—such as PET scans.
In simple terms: Imaging or treatment that uses small amounts of radiation to see how organs work.

nucleus (spine)

The soft, gel-like center of spinal discs between vertebrae.
In simple terms: The inner cushion of spinal discs.

numbing agent

See local anesthetic.
In simple terms: Medicine that makes an area lose feeling so you don’t feel pain.

O

occluded

Blocked.
In simple terms: Something is clogged or obstructed (like a blocked blood vessel).

oncologist

A doctor who specializes in diagnosing and treating cancer.
In simple terms: A cancer doctor.

oncology

The study and treatment of tumors and cancer.
In simple terms: The medical field focused on cancer care.

oophorectomy

Surgical removal of one or both ovaries.
In simple terms: Surgery to remove an ovary (or both ovaries).

optionally retrievable filters

A temporary device placed inside the inferior vena cava (large vein) to catch blood clots and prevent them from reaching the heart or lungs.
In simple terms: A removable filter placed in a major vein to block dangerous clots.

orchitis

Inflammation of one or both testicles, often caused by infection.
In simple terms: Swelling or infection of the testicles.

orthopedic cement

A strong acrylic material used in bone surgeries and fracture repair.
In simple terms: Special medical glue used to fix bones during surgery.

orthopedics

The medical specialty that treats bones, muscles, joints, and the spine.
In simple terms: The branch of medicine focused on the bones and movement system.

osteoarthritis

A common condition caused by wear and tear of joints over time.
In simple terms: Age-related joint damage that causes pain and stiffness.

osteomyelitis

A bone infection.
In simple terms: Infection in the bone.

osteopenia

Low bone density—an early sign of bone loss that can lead to osteoporosis.
In simple terms: Early stage of weak bones; warning sign before full osteoporosis.

osteoporosis

A condition where bones become thin and fragile, making fractures more likely.
In simple terms: Weak, brittle bones that break easily—especially with age.

ovary

One of two female glands that store and release eggs during ovulation.
In simple terms: Female organ that produces eggs for reproduction.

ovulation

Release of an egg from the ovary into the fallopian tube for possible fertilization.
In simple terms: When an egg is released from the ovary—part of the monthly cycle.

P

pacemaker

See cardiac pacemaker.
In simple terms: A small device implanted to help the heart beat regularly.

Paget disease

A condition where bones break down and rebuild too quickly, leading to weak or misshapen bones.
In simple terms: A bone disorder that makes bones become large and deformed.

palliative treatment

Treatment meant to relieve symptoms rather than cure the disease.
In simple terms: Care focused on comfort—not curing—often used in serious illness.

palpable

Able to be felt by touch

Clearly noticeable
In simple terms: Something you can easily feel or notice.

pancreas

A gland that makes digestive enzymes and hormones like insulin.
In simple terms: An organ that helps with digestion and controls blood sugar.

pancreatic duct

The tube that carries digestive enzymes from the pancreas to the intestine.
In simple terms: A passage that connects the pancreas to the intestines for digestion.

pancreatitis

Inflammation of the pancreas.
In simple terms: Swelling or irritation of the pancreas.

pancreatography

Imaging test of the pancreatic ducts—using contrast for x-ray or MRI.
In simple terms: A scan to look at the ducts of the pancreas.

Pap test (Pap smear)

A test where cells are taken from a woman’s cervix to check for cancer.
In simple terms: A screening test for cervical cancer.

papilloma

A usually benign tumor that appears on skin or mucous membranes.
In simple terms: A small, noncancerous growth (similar to a wart).

paranasal

Located beside the nose.
In simple terms: Next to the nose.

paranasal sinuses

Air-filled spaces in facial bones connected to the nose.
In simple terms: Hollow areas around the nose that help with breathing and voice.

parathyroid glands

Four tiny glands in the neck that regulate calcium and phosphorus levels.
In simple terms: Small neck glands that control calcium balance in the body.

partial colectomy

Surgical removal of part of the colon.
In simple terms: Surgery to remove part of the large intestine.

particulate agents

Man-made materials injected into blood vessels to block blood flow—used to stop bleeding or cut off blood to tumors.
In simple terms: Particles used to intentionally block blood flow during treatment.

patency

The state of being open or unblocked.
In simple terms: When a tube or vessel is clear and not clogged.

pathologist

A doctor who examines cells and tissues to diagnose disease.
In simple terms: A doctor who studies samples to find illness—often cancer.

pathology

The study of disease processes.
In simple terms: The science of diagnosing diseases.

pelvic floor dysfunction

A group of conditions affecting muscles supporting pelvic organs, causing pain, constipation, or organ movement.
In simple terms: Weak pelvic muscles that can cause bowel, bladder, or organ problems.

penetrating injury

An injury where the skin is pierced, usually by a sharp object.
In simple terms: A deep wound that breaks the skin, like a stab or cut.

percutaneous

Going through the skin—by needle, catheter, or absorption.
In simple terms: Entering the body through the skin, usually with a needle.

percutaneous transhepatic cholangiography (PTC)

An x-ray test where contrast is injected into the liver to visualize bile ducts.
In simple terms: A liver scan using a dye to examine bile ducts.

perforation

A hole in an organ or tissue caused by trauma or disease.
In simple terms: A tear or hole in an organ.

perfusion

The flow of blood or fluid to an organ.
In simple terms: Blood flow to body parts.

perineum

The area between the genitals and anus.
In simple terms: The skin between the private parts and the anus.

periodontal disease

Disease affecting gums and bone around the teeth.
In simple terms: Gum disease.

peripheral artery disease (PAD)

Narrowing or blockage of arteries in the arms or legs due to plaque.
In simple terms: Poor blood flow to the legs or arms—can cause pain when walking.

peripherally inserted central catheter (PICC)

A long-term IV line placed in a major vein through the arm or leg.
In simple terms: A long IV tube used for weeks or months to give medicine or draw blood.

peritoneal cavity

The empty space in the abdomen not filled by organs.
In simple terms: The open area inside the belly around the organs.

peritoneal port

A small implanted chamber for delivering medication or fluids into the abdominal cavity.
In simple terms: A device under the skin used to access the belly for treatments.

peritoneum

A thin tissue lining the abdominal cavity.
In simple terms: The lining inside the belly.

permanent brachytherapy (seed implantation)

Radiation treatment where radioactive seeds are permanently placed near a tumor.
In simple terms: Tiny radiation seeds implanted to treat cancer.

peroxide (hydrogen peroxide)

A liquid used for disinfecting and bleaching.
In simple terms: Common antiseptic used for cleaning wounds.

petit mal seizure (absence seizure)

A brief seizure where the person stares into space and becomes unresponsive.
In simple terms: A short staring spell often seen in epilepsy.

pharynx

The throat area behind the nose and mouth.
In simple terms: The throat.

phlebitis

Painful inflammation of a vein.
In simple terms: Swollen or irritated vein.

pituitary adenoma

A benign tumor in the pituitary gland that may affect hormones.
In simple terms: A noncancerous growth in the hormone-controlling gland under the brain.

pituitary gland

A gland beneath the brain that controls many hormone functions.
In simple terms: The “master gland” that controls hormones in the body.

plaque

Fat buildup inside blood vessels that can narrow or block them.
In simple terms: Cholesterol buildup in arteries.

platelets

Blood particles that help with clotting.
In simple terms: Cells that stop bleeding when you get a cut.

pleural effusion

Excess fluid in the space around the lungs.
In simple terms: Fluid buildup around the lungs.

pleural space (pleural cavity)

The area between the lungs and chest wall.
In simple terms: The small space around your lungs.

pneumonia

Infection that causes inflammation in one or both lungs.
In simple terms: Lung infection.

pneumothorax

Air trapped in the pleural space that can collapse the lung.
In simple terms: Collapsed lung due to air leaking into the chest.

polycythemia

A condition with too many red blood cells.
In simple terms: Too many red blood cells in the blood.

polyp

A usually benign growth that sticks out from tissue.
In simple terms: A small growth, often found in the colon or nose.

polypectomy

Removal of polyps from the colon or rectum.
In simple terms: Procedure to remove abnormal growths in the intestine.

porous

Having tiny holes or spaces.
In simple terms: Full of small openings.

portal hypertension

High pressure in liver veins due to blocked blood flow.
In simple terms: Increased pressure in liver blood vessels.

portal vein

Main vein that carries blood from the digestive system to the liver.
In simple terms: The major vein that brings blood from the stomach and intestines to the liver.

positron emission tomography (PET)

A scan using radioactive tracers to detect early disease at the cellular level.
In simple terms: A specialized scan that shows how organs are working—not just how they look.

post-embolization syndrome

Symptoms like pain, nausea, and fever after embolization treatment.
In simple terms: Common side effects after blocking blood flow to a tumor.

power Doppler

An ultrasound technique that is highly sensitive to blood flow but doesn’t show direction.
In simple terms: A stronger type of ultrasound used to find blood flow more clearly.

precancerous

Abnormal tissue that may become cancer in the future.
In simple terms: Early warning signs before cancer starts.

primary aldosteronism

A condition where the adrenal glands produce too much aldosterone, causing high blood pressure.
In simple terms: Hormone problem that leads to high blood pressure.

primary headache

Headaches not caused by another medical condition (e.g., migraine).
In simple terms: Headaches that are not due to another disease.

primary tumor

The original site where cancer starts.
In simple terms: The first tumor before cancer spreads.

probe

Tool used to explore a body cavity Lab tool to detect substances like DNA
In simple terms: A tool used to explore or detect things in the body.

proctocolectomy

Surgery to remove the rectum and part or all of the colon.
In simple terms: Removal of the lower bowel and rectum.

proctoscopy

A procedure using a camera to view the inside of the rectum.
In simple terms: A scope used to look inside the rectum.

prognostic

Related to predicting the outcome of a disease.
In simple terms: Tells how likely recovery is.

prostate cancer

Cancer that forms in the prostate gland.
In simple terms: Cancer in a man’s prostate.

prostate gland

A walnut-sized gland in men that makes fluid for semen.
In simple terms: A male gland that helps make sperm fluid.

prostate-specific antigen (PSA)

A protein measured in a blood test to help detect prostate cancer.
In simple terms: A blood test used to check prostate health.

proton

A positively charged particle found in every atom’s nucleus.
In simple terms: A basic part of atoms—one of the building blocks of matter.

pulmonary

Related to the lungs.
In simple terms: Involving the lungs.

pulmonary edema

Fluid buildup in the lungs.
In simple terms: Fluid in the lungs causing breathing trouble.

pulmonary embolism

A blood clot blocking an artery in the lungs.
In simple terms: A dangerous clot that travels to the lungs.

pulmonary hypertension

High blood pressure in the lung blood vessels.
In simple terms: High lung blood pressure.

pulmonologist

A doctor specializing in lung diseases.
In simple terms: Lung specialist.

pulse oximetry

A fingertip device that measures oxygen in the blood.
In simple terms: A quick test to check oxygen levels.

pyelonephritis

Kidney infection, usually from a urinary tract infection spreading upward.
In simple terms: A serious kidney infection.

pylorus

The opening from the stomach to the small intestine.
In simple terms: The exit of the stomach into the intestines.

R

radiation

Radiant energy found in waves or particles.
In simple terms: Energy that can travel through space—like x-rays, sunlight, or radio waves.

radiation oncologist

Doctors who plan and monitor radiation treatment for cancer patients. They also manage side effects and work with the radiation team.
In simple terms: A cancer doctor who specializes in treating tumors with radiation.

radiation oncology (radiation therapy)

The study and use of radiation to treat abnormal tissue growths.
In simple terms: Using radiation to treat cancer or tumors.

radiation oncology nurses

Nurses who care for patients receiving radiation therapy, educate them, and help manage side effects.
In simple terms: Nurses who support cancer patients during radiation treatment.

radiation pneumonitis

Inflammation of lung tissue caused by radiation therapy.
In simple terms: Lung irritation that can happen after radiation treatment.

radiation therapist

Professionals who operate radiation machines and administer daily radiation treatments under medical supervision.
In simple terms: A specialist who gives radiation treatments to patients.

radiation therapy (radiotherapy)

The medical use of radiation to treat disease, especially cancer.
In simple terms: Treatment that uses radiation to kill cancer cells.

radiation units

Measurements of radiation exposure or dose, including:
rad – Energy absorbed by tissue
gray (Gy) – 100 rad
milligray (mGy) – 0.1 rad
em – Measures biological impact of radiation
millirem – One thousandth of a rem
roentgen (R) – Exposure to x-rays or gamma rays
sievert (Sv) – Effective dose considering tissue sensitivity
millisievert (mSv) – One thousandth of a sievert
In simple terms: Different measurement units for how much radiation the body receives.

radioactive

Something that emits radiation.
In simple terms: Gives off energy that may be harmful in large amounts.

radioactive iodine I-131 (radioiodine)

A type of iodine that gives off radiation and is used medically.
In simple terms: A radioactive form of iodine used for imaging or treating thyroid problems.

radioactive iodine I-131 therapy

Treatment for hyperthyroidism using radioactive iodine that destroys overactive thyroid cells.
In simple terms: A pill used to treat an overactive thyroid by shrinking it with radiation.

radioactive material (radioactive substance)

Material that gives off radiation and is often sealed inside small pellets for cancer treatment.
In simple terms: Radioactive seeds placed in the body to treat cancer.

radiofrequency ablation

Treatment that uses electrical energy to heat and destroy tissue or tumors.
In simple terms: Using heat from electrical waves to burn away abnormal tissue.

radiofrequency electrodes

Thin wires used to deliver radiofrequency energy during ablation or to seal blood vessels.
In simple terms: Wires used to deliver heat and destroy tissue during treatment.

radiography

X-ray imaging for diagnosis, saved on film or digitally.
In simple terms: Taking x-ray pictures to diagnose medical problems.

radioimmunotherapy

A treatment combining radiation therapy and immunotherapy to target tumors.
In simple terms: A combined cancer treatment that delivers radiation directly to cancer cells.

radioisotope bone scan

A nuclear medicine scan that uses radioactive material to detect bone abnormalities.
In simple terms: An imaging test that shows bone problems using a small amount of radiation.

radiologist

A physician trained in medical imaging such as x-rays, CT, MRI, or ultrasound.
In simple terms: A doctor who reads medical scans.

radiology

The medical field that uses imaging and radiation to diagnose and treat diseases.
In simple terms: The science of using medical images like x-rays and MRIs to find and treat illness.

radionuclide

A radioactive isotope used in imaging and treatment of diseases.
In simple terms: A radioactive substance used in medical scans.

radiopaque

Impenetrable by x-rays.
In simple terms: Shows up clearly on x-rays because radiation cannot pass through it.

radiopharmaceutical (radiotracer)

A radioactive drug used in diagnostic imaging or treatment.
In simple terms: Medicine that contains radiation to help doctors see or treat disease.

radiotherapy

Use of radiation to treat disease.
In simple terms: Radiation treatment, usually for cancer.

radon

A naturally occurring radioactive gas that can cause lung cancer if inhaled in high amounts.
In simple terms: A dangerous gas found in some homes that can cause lung cancer.

rectal prolapse

When part of the rectum slips outside the body through the anus.
In simple terms: The rectum falling out through the anus.

rectum

The lower part of the colon where stool is formed.
In simple terms: The last section of the digestive tract before waste leaves the body.

red blood cells (erythrocytes)

Cells that carry oxygen and carbon dioxide through the bloodstream.
In simple terms: Blood cells that transport oxygen to the body.

Reed-Sternberg cell

A type of cell seen in Hodgkin lymphoma.
In simple terms: A marker cell used to diagnose Hodgkin lymphoma.

referring physician

A doctor who sends a patient to a specialist for more care or diagnosis.
In simple terms: A doctor who refers you to another specialist.

regurgitation

The backward flow of undigested food from the esophagus to the mouth.
In simple terms: Food coming back up—similar to reflux or spitting up.

renal hypertension

High blood pressure caused by narrowing of the kidney arteries.
In simple terms: High blood pressure due to kidney problems.

reproductive

Related to organs involved in reproduction.
In simple terms: Involves the body's sex and fertility organs.

respiratory

Related to breathing and airflow in and out of the lungs.
In simple terms: About breathing and lung function.

respiratory therapy

Treatments used to improve lung function.
In simple terms: Therapy to help people breathe better.

restenosis

Re-narrowing of an artery after it was previously widened.
In simple terms: The artery closing again after being opened.

rheumatoid arthritis

An autoimmune disease where the immune system attacks the joints.
In simple terms: A type of arthritis that causes painful, swollen joints.

Rituximab®

A monoclonal antibody used to treat non-Hodgkin lymphoma.
In simple terms: A drug that targets cancer cells in lymphoma.

rotator cuff

A group of shoulder muscles that help lift and rotate the arm.
In simple terms: Shoulder muscles that allow arm movement and stability.

S

sacroiliac joint

The joint in the pelvis between the sacrum and the ilium of the pelvis.
In simple terms: The joint that connects the spine to the pelvis.

saline

Salt water.
In simple terms: Sterile salty water often used in IVs and for cleaning wounds.

salpingo-oophorectomy

The removal of the ovaries and fallopian tubes.
In simple terms: Surgery to remove a woman’s ovaries and fallopian tubes.

sarcoma

A cancerous tumor that occurs in the connective tissues of the body, such as the bones, cartilage, tendons and soft tissues.
In simple terms: A type of cancer that starts in bones or soft tissues.

scan(s)

To survey by traversing with an active or passive sensing device. The image, record, or data obtained by scanning, usually identified by the technology or device employed; e.g., CT scan, radionuclide scan, ultrasound scan.
In simple terms: A medical picture of the inside of the body, made with machines like CT, MRI, or ultrasound.

scintigraphy

A diagnostic procedure. It consists of administering a radionuclide that accumulates in the organ or tissue of interest. Then the distribution of the radioactivity is recorded with a stationary or scanning external scintillation camera.
In simple terms: A nuclear medicine test that uses a small amount of radioactive material to take pictures of organs.

sclerosing

Causing scarring. Liquid chemicals or alcohols used to destroy blood vessels in an embolization procedure. Sclerosing damages the inner lining of a vessel and causes blood clots to form, thus preventing blood flow.
In simple terms: Using chemicals to scar and close off a blood vessel so blood can’t flow through it.

sclerosing cholangitis

Inflammation of the bile ducts.
In simple terms: Long-term swelling and scarring of the tubes that carry bile from the liver.

scoliosis

A side-to-side curvature of the spine. It usually develops in childhood or adolescence.
In simple terms: A curved spine that bends sideways.

scrotum

A muscular sac that contains the testes.
In simple terms: The pouch of skin that holds the testicles.

secondary headache

One of the two major types of headaches. Secondary headaches are caused by an injury or underlying illness, such as bleeding in the brain, an infection or a brain tumor.
In simple terms: A headache that happens because of another medical problem, like an infection or trauma.

secondary hyperparathyroidism

A condition in which one or more of the body’s four parathyroid glands produces too much parathyroid hormone due to low calcium levels in the blood. Symptoms include bone and joint pain.
In simple terms: Overactive parathyroid glands caused by low blood calcium, often leading to bone pain.

secure sockets layer (SSL)

A cryptographic communications protocol that provides secure transmissions on the Internet by encoding/decoding the data transfers.
In simple terms: A way websites encrypt data so information sent online is secure.

sedation, deep

A level of sedation in which patients will generally sleep during the procedure without responding to painful stimulation. Patients will be able to breathe on their own and in many cases will receive oxygen from a face mask. See sedation, minimal and moderate.
In simple terms: Medicine that makes you sleep very deeply during a procedure, but you still breathe on your own.

sedation, minimal and moderate

Levels of sedation in which the patient receives a drug to relax but remains responsive to verbal questions and painful stimulation. Patient is able to breathe independently during a surgical or medical procedure. See sedation, deep.
In simple terms: Light to medium sedation that relaxes you but keeps you awake and able to respond.

sedative

A drug that allows you to relax during a procedure, often without putting you to sleep.
In simple terms: A calming medicine that helps you feel relaxed.

seizure

A sudden, uncontrollable wave of electrical activity in the brain. It can cause involuntary bodily movement, a change in attention or a loss of consciousness.
In simple terms: A sudden episode where the brain misfires, causing shaking, confusion, or loss of awareness.

seizure disorders

A condition marked by sudden, uncontrollable waves of electrical activity in the brain. It can cause involuntary movement or loss of consciousness.
In simple terms: Conditions like epilepsy that cause repeated seizures.

serial paracentesis

A minimally invasive procedure. Excess fluids in the abdomen are repeatedly withdrawn through a needle inserted directly into the peritoneal cavity or through a catheter connected to a peritoneal port.
In simple terms: Repeated draining of fluid from the belly using a needle or tube.

sexually transmitted diseases (STDs)

Any infectious disease that is passed from one person to another during sex.
In simple terms: Infections you can catch through sexual contact.

shear injury (diffuse axonal injury)

Stretched or torn nerve fibers in the brain.
In simple terms: Brain damage caused by the brain shaking and nerve fibers tearing, often from trauma.

sheath

A short, hollow plastic tube inserted through the skin into a blood vessel or tissue. It allows other instruments, such as a guide wire and balloon-tipped catheter to enter the body.
In simple terms: A short tube placed in a vessel so other tools can be passed through it.

short-bore MRI system

A type of MRI unit where the magnet is shorter, allowing part of the body to be outside the tube. Patients often report less claustrophobia compared to standard MRI.
In simple terms: A shorter MRI machine that feels less enclosed for the patient.

sickle-cell anemia

A severe, chronic type of anemia caused by an abnormal form of hemoglobin that distorts the red blood cells. These abnormal red blood cells sometimes plug the blood vessels, causing damage to the organ downstream.
In simple terms: An inherited blood disease where red cells become sickle-shaped and can block blood flow.

sigmoid colon

The lower part of the colon.
In simple terms: The S-shaped last section of the large intestine before the rectum.

sigmoidoscope

A thin flexible tube with a tiny camera at the end used in a procedure called a sigmoidoscopy. It captures images of the interior of the lower large intestine and rectum.
In simple terms: A small camera tube used to look inside the lower colon.

sigmoidoscopy

An exam in which a flexible tube with a tiny camera at the end called a sigmoidoscope is inserted into the colon. It is used to capture images of the interior of the lower colon and rectum.
In simple terms: A scope test that looks inside the lower part of the large intestine.

simulation

Use of a radiographic system or computer to plan radiation therapy. See also treatment planning.
In simple terms: A practice/planning session with imaging to map out where radiation will go.

single-photon emission-computed tomography (SPECT)

An imaging test that uses a gamma camera and a computer to create three-dimensional (3-D) images of radiotracers in the body. SPECT is used to study blood flow through the heart muscle, and to study the brain, bones and to detect infection and certain types of tumors.
In simple terms: A 3D nuclear medicine scan that shows how blood flows or how organs are working.

sinus (sinuses)

Hollow, air-filled spaces located within the bones of the face surrounding the nasal cavity. There are four pairs of cavities, called paranasal sinuses, each of which is connected to the nose by small openings.
In simple terms: Air pockets in the bones around your nose and eyes.

sinusitis

Infection or inflammation of one or more of the sinuses.
In simple terms: A sinus infection or inflamed sinuses.

small intestine

The section of the gastrointestinal tract that digests food and absorbs nutrients after they have passed through the stomach.
In simple terms: The long, coiled part of the gut where most digestion and nutrient absorption happens.

social workers

Social workers may be available to provide practical help and counseling to patients or members of their families and can help them to cope. They also may help arrange for home health care and other services. Social workers may be licensed. Licensed social workers must have a master's degree and must pass an examination.
In simple terms: Professionals who help patients and families with emotional support, resources, and practical needs.

sonication

A pulse of ultrasonic energy. It is used to heat up and destroy diseased tissue.
In simple terms: Using focused sound waves to heat and kill abnormal tissue.

sonographer

A health professional who has been specifically trained to perform ultrasound exams.
In simple terms: A specialist who performs ultrasound scans.

sonography (ultrasonography)

The imaging of body structures by measuring the reflection or transmission of high frequency sound waves.
In simple terms: Using sound waves to create images of organs inside the body (ultrasound).

sonohysterography

Sonography of the uterus and fallopian tubes using a transvaginal probe. It follows the injection of sterile saline into the uterus via a thin catheter inserted through the cervix.
In simple terms: An ultrasound test of the uterus and tubes after filling the uterus with sterile fluid.

spectral Doppler

Displays the blood flow measurements graphically, showing flow velocities over time instead of just colors.
In simple terms: An ultrasound mode that shows blood flow speed as a graph.

speculum

An instrument for enlarging the opening of a canal or cavity in order to inspect its interior. It is most frequently used with Pap tests.
In simple terms: The tool used during a pelvic exam to gently open the vagina so the cervix can be seen.

sperm

It is the male reproductive cell carried by semen through the penis when a man ejaculates.
In simple terms: Male reproductive cells that can fertilize an egg.

spinal anesthesia

Injection of a local anesthetic into the subarachnoid space surrounding the spinal cord. It is generally used to prevent pain and movement in areas below the chest and extending to the feet.
In simple terms: A numbing injection in the lower back that blocks feeling in the lower body.

spinal canal

The cavity within the vertebral column through which the spinal cord passes.
In simple terms: The hollow tunnel inside the spine where the spinal cord runs.

spinal cord

A bundle of nerves, lying within the vertebral column, that carries sensory messages from peripheral nerves to the brain and motor impulses from the brain to the body's muscles.
In simple terms: The main nerve pathway running from the brain down the back.

spinal fusion

Surgical fixation of an unstable segment of the spine.
In simple terms: Surgery to permanently join two or more bones in the spine.

spirometer

A device that measures the volume of air that moves in and out of the lungs.
In simple terms: A machine used to test how much air you can breathe in and out.

spirometry

A test of lung function using a spirometer.
In simple terms: A breathing test that measures lung capacity.

spleen

A large organ located in the left, upper abdomen, beside the stomach. It is part of the immune system, producing white blood cells and acts as a blood filter.
In simple terms: An organ that helps fight infection and filters blood.

spontaneous pneumothorax

A condition in which a collection of air in the pleural space causes the lung to collapse. This occurs in the absence of disease or injury.
In simple terms: A sudden collapsed lung that happens without obvious injury.

sputum

A mixture of saliva and mucus coughed up from the respiratory tract.
In simple terms: Mucus you cough up from your chest.

sputum cytology

A diagnostic test in which a sample of sputum is examined under a microscope. It determines whether abnormal cells are present.
In simple terms: Checking mucus from the lungs under a microscope to look for abnormal or cancer cells.

squamous cell carcinoma

A cancer that develops in the thin, flat cells (called squamous) that make up the outer layer of the skin.
In simple terms: A common type of skin cancer that starts in the top layer of the skin.

stage

Extent or progression of a disease such as cancer.
In simple terms: How advanced the cancer or disease is.

staging

Determining the extent or progression of a disease such as cancer.
In simple terms: The process of figuring out how far cancer has spread.

stem cell transplant

Diseased bone marrow is replaced with the patient's own healthy stem cells or the stem cells of a donor. This is done in order to help new bone marrow grow.
In simple terms: A procedure that replaces damaged blood-forming cells with healthy ones.

stenosis, pl. stenoses (stricture)

An abnormal narrowing of any canal. For example, a narrowing of one of the cardiac valves. Narrowing of an opening or passageway in the body. Stenosis of an artery may reduce blood flow through the vessel.
In simple terms: A tightening or narrowing of a tube in the body, like a blood vessel or valve.

stent

Slender thread, rod, or catheter lying within the space in the interior of a tubular structure. It is used to provide support during or after opening surgically, or to assure the opening of an intact but contracted lumen.
In simple terms: A tiny tube used to keep a blood vessel or duct open.

stent graft

A synthetic tube-like device used to replace a portion of an artery that has weakened and bulged (called an aneurysm).
In simple terms: A reinforced tube placed inside a damaged artery to strengthen it and prevent rupture.

stenting

The act of placing a stent.
In simple terms: Putting in a stent to keep a vessel open.

stereotactic biopsy

An x-ray procedure. It uses multiple coordinates to precisely determine the location of a tumor or nodule so that a tissue sample may be obtained.
In simple terms: A precisely guided biopsy that uses imaging to target a small lesion.

stereotactic radiosurgery

A highly precise form of radiation therapy. It directs narrow beams of radiation from different angles at a brain tumor or abnormality, minimizing radiation to healthy tissue.
In simple terms: A focused radiation treatment for brain problems that doesn’t require cutting.

stereotactic radiotherapy

A form of stereotactic radiosurgery using smaller doses over several days or weeks to minimize tissue damage.
In simple terms: Repeated, precise radiation sessions to a small brain area over time.

stress echocardiography

A test in which ultrasound is used to create moving pictures of the heart before and after the heart is stressed by exercise or medication.
In simple terms: An ultrasound of the heart done while it’s working hard, like during exercise.

stress test

A heart monitoring test to discover how well the heart works under stress, usually exercise or medication.
In simple terms: A test that checks how your heart performs when it’s beating faster.

stroke

A stroke occurs when a blood vessel that carries oxygen and nutrients to the brain is either blocked by a clot or bursts, interrupting blood flow to an area of the brain.
In simple terms: Brain damage caused by loss of blood flow to part of the brain.

subarachnoid hemorrhage

Blood collection between middle and inner linings of the brain, often from trauma or a ruptured aneurysm.
In simple terms: Bleeding in the space around the brain, often from a burst aneurysm.

subarachnoid space

The space between the membrane covering the spinal cord and the cord itself.
In simple terms: The fluid-filled space around the brain and spinal cord.

subcutaneous port

A permanent vascular access device placed under the skin and connected to a major vein for long-term blood draws or treatments.
In simple terms: A small device under the skin that makes it easier to give IV treatments or take blood over months/years.

subdural hematoma

Bleeding between the brain surface and its outer coverings, usually from a burst vein, with symptoms that can appear slowly.
In simple terms: A slow brain bleed under the skull, often after a head injury.

superior vena cava

One of the largest veins in the body. It returns blood from the upper half of the body to the heart.
In simple terms: The big vein that carries blood from the head and arms back to the heart.

surgical shunt

A surgically created passageway to allow fluids like blood to flow between two places.
In simple terms: A surgically made tunnel that redirects fluid or blood in the body.

synchrotron

A large ring-shaped particle accelerator that can produce very high energy particles, such as protons or carbon ions, used to treat cancer.
In simple terms: A big machine that speeds up particles to high energies, sometimes used for advanced cancer treatments.

syphilis

A sexually transmitted disease that can cause serious damage to the nervous system and heart if not treated.
In simple terms: A sexually transmitted infection that can become serious if untreated.

T

targeted therapy

See monoclonal antibody therapy.
In simple terms: Cancer treatment that aims directly at specific molecules on cancer cells instead of attacking all fast-growing cells.

technetium-99m

A radiotracer commonly used in nuclear medicine for many different types of exams. It decays within 24 hours, leaving no residual radiation.
In simple terms: A short-lasting radioactive substance used in many scans that’s mostly gone from the body within a day.

technologist

One trained in and using the techniques of a profession, art, or science.
In simple terms: A trained professional who operates medical equipment or performs technical procedures (like radiology techs, ultrasound techs).

temporary brachytherapy

A radiation therapy treatment for cancer. A radioactive seed is placed in or near a tumor for a set time, then removed. It can be low dose rate (LDR) or high dose rate (HDR).
In simple terms: Short-term internal radiation where radioactive seeds are put in the body for a while and then taken out.

temporomandibular joint disorder (TMJ)

A group of disorders causing pain in the face, jaw muscles, jaw joint, and nearby nerves.
In simple terms: Jaw joint problems that cause pain, clicking, or difficulty opening the mouth.

tension headache

A headache with pressure and band-like tightness starting in the back of the head and neck and wrapping around the head.
In simple terms: A common “stress headache” that feels like a tight band around the head.

testis (pl. testes)

One of the two male glands that produce sperm and testosterone, located in the scrotum.
In simple terms: Testicle—the male organ that makes sperm and male hormones.

thoracic

Refers to the chest or ribs region of the spine (vertebrae T1–T12).
In simple terms: Middle back area where the ribs attach.

three-dimensional conformal radiation therapy (3D-CRT)

A type of external radiation that shapes the radiation beams to match the tumor so higher doses can be given safely.
In simple terms: A precise radiation technique that molds the beam to the shape of the tumor.

thrombolysis

See Catheter-directed Thrombolysis.
In simple terms: Breaking up blood clots using medicine, often delivered through a catheter.

thrombolytic agent

A medication used to dissolve blood clots in blood vessels.
In simple terms: “Clot-busting” drug.

thrombolytic therapy

The use of medication to break up or dissolve blood clots.
In simple terms: Treatment that dissolves clots to restore blood flow.

thrombophlebitis

Inflammation of a vein due to a blood clot forming along its wall.
In simple terms: A painful, swollen vein caused by a clot.

thrombosis

Blocking of a blood vessel by a clot that forms there.
In simple terms: A blood clot that forms and blocks a vein or artery.

thrombotic stroke

A stroke that occurs when a clot forms inside a brain blood vessel that is already narrowed.
In simple terms: A stroke caused by a clot forming right in a brain artery.

thyroid gland

A butterfly-shaped gland in the front of the neck that makes hormones that control metabolism, heart rate, weight, energy, and more.
In simple terms: A neck gland that controls how fast the body works (metabolism).

tissue plasminogen activator (t-PA)

A clot-busting drug used to reduce the severity of an ischemic stroke if given quickly after symptoms start.
In simple terms: Emergency medicine that can dissolve a stroke-causing clot if given early.

tonic-clonic seizure

See grand mal seizure.
In simple terms: A seizure with loss of consciousness and full-body shaking.

total body irradiation

Radiation therapy where the entire body is treated before chemotherapy and a stem cell or bone marrow transplant.
In simple terms: Whole-body radiation used to prepare for a bone marrow or stem cell transplant.

total nodal irradiation

Radiation therapy to all the lymph nodes in the body.
In simple terms: Radiation aimed at all lymph node areas.

trachea (windpipe)

The tube that connects the mouth and nose to the lungs.
In simple terms: The airway tube from the throat down to the lungs.

transabdominal

Through or across the abdomen.
In simple terms: Going through the belly.

transducer

A handheld device that sends and receives ultrasound signals.
In simple terms: The ultrasound “probe” placed on the skin to create images.

transient ischemic attack (TIA)

A temporary blockage of blood flow to the brain, often called a mini stroke. Symptoms usually resolve within a day.
In simple terms: A short-lived stroke warning—symptoms go away, but it signals high stroke risk.

transplant

To transfer tissue or an organ from one place to another. Or, the tissue or organ being transferred.
In simple terms: Moving an organ or tissue (like a kidney) into another part of the body or another person.

transrectal

Passing through or done via the rectum.
In simple terms: Through the rectum (back passage).

transvaginal

Across or through the vagina.
In simple terms: Through the vagina.

treatment planning

Creating a detailed plan to deliver effective radiation therapy while minimizing damage to healthy tissue.
In simple terms: Carefully designing where and how radiation will be given.

trocar

A hollow needle with a sharp tip used to access a body cavity, vessel, or bone so other instruments can be passed through it.
In simple terms: A sharp tube used to make an opening so other tools can be inserted.

tuberculosis

A highly contagious infection spread through the air that mainly attacks the lungs, but can affect other organs.
In simple terms: A serious lung infection (TB) that spreads through coughing.

tumor

A growth of abnormal cells that may be benign or malignant (cancerous).
In simple terms: An abnormal lump or mass of cells.

tumor ablation

The removal or destruction of a tumor.
In simple terms: Destroying or removing a tumor (often with heat, cold, or chemicals).

tunneled catheter

A long-term catheter placed in a large vein and “tunneled” under the skin, with a cuff that helps hold it in place. Often used for dialysis or long-term treatments.
In simple terms: A permanent IV tube that runs under the skin into a big vein for frequent access.

U

ulcerative colitis

A chronic disease of unknown cause characterized by ulceration of the colon and rectum. Symptoms include rectal bleeding, abdominal pain, and diarrhea; frequently causes anemia and electrolyte imbalance. Less often, it may lead to inflammation of the abdominal membrane, toxic megacolon, or colon cancer.
In simple terms: A long-term disease that causes sores and inflammation in the colon and rectum, leading to bloody diarrhea and pain. It can be serious if not treated.

ulcers (of the skin)

An open sore or irritation on the skin.
In simple terms: A wound on the skin that doesn’t heal properly.

ulcers (of the stomach)

A sore or erosion in the lining of the stomach.
In simple terms: A painful sore inside the stomach, often caused by stress, infection, or acid.

ultrasonography

See sonography.
In simple terms: Another name for ultrasound imaging.

ultrasound, diagnostic (ul-tra-sownd)

Also known as ultrasound scanning or sonography. A method of taking images inside the body using high-frequency sound waves. No radiation is involved.
In simple terms: A safe imaging test that uses sound waves to make pictures of organs—often used for pregnancy scans.

ureter

The tube that carries urine from each kidney to the bladder.
In simple terms: A urine-carrying tube from the kidney to the bladder.

urethra

A tube that carries urine from the bladder out of the body. In men, it also carries semen out through the penis.
In simple terms: The tube that urine (and semen in men) travels through to leave the body.

uric acid

A waste product from normal chemical processes in the body, found in urine and blood.
In simple terms: A chemical waste in the body; high levels can cause gout.

urinary

Relating to the organs involved in making and passing urine.
In simple terms: Having to do with pee and the organs that make or remove it.

urologist

A doctor who specializes in diagnosing and treating diseases of the urinary and genital organs.
In simple terms: A urinary and reproductive system specialist (e.g., prostate, bladder, kidneys).

uterine

Relating to the uterus.
In simple terms: Having to do with the womb.

uterine cavity

The space within the uterus.
In simple terms: The inside area of the womb.

uterus

A hollow muscular organ in a woman’s lower abdomen where a fertilized egg develops into a baby.
In simple terms: The womb — where a baby grows during pregnancy.

V

V/Q Lung Scan

A nuclear medicine exam that uses a small amount of radioactive material to show how blood and air flow throughout the lungs.
In simple terms: A scan that checks how well air and blood move through the lungs using a tiny amount of radiation.

vacuum-assisted biopsy

A type of biopsy in which a vacuum-powered instrument is inserted through the skin to collect cells without removing the needle after each sampling.
In simple terms: A sample of tissue taken with a suction device so multiple samples can be collected quickly with one needle.

vagina

The genital canal in the female, extending from the uterus to the vulva.
In simple terms: The birth canal and passage that connects the uterus to the outside of the body.

vagus nerve

One of two major nerves that control automatic body functions such as digestion, heart rate, and breathing.
In simple terms: A nerve that controls automatic things like your heartbeat and digestion.

venogram

X-ray imaging of veins after contrast material is injected.
In simple terms: A special X-ray test that shows how veins look by using dye.

venography (vE-nog-ra-fE)

A type of X-ray test using contrast material to view vein structure and detect problems.
In simple terms: A scan that shows detailed pictures of veins using injected dye.

venous malformation (VM)

Abnormally formed veins that may enlarge with time.
In simple terms: A birth defect where veins grow incorrectly and may swell or cause pain.

ventricles

1. Brain: hollow spaces containing cerebrospinal fluid. 2. Heart: the main pumping chambers.
In simple terms: Chambers that pump blood in the heart—or spaces that hold fluid in the brain.

vertebra

A bone in the spinal column that protects the spinal cord.
In simple terms: One of the spine bones.

vertebrae

The bony segments of the spinal column protecting the spinal cord.
In simple terms: The set of bones that make up the spine.

vertebral compression fractures

Fractures caused when one spine bone pushes down on another.
In simple terms: Broken back bones often caused by weak bones (like in osteoporosis).

vertebroplasty

A minimally invasive procedure that injects bone cement to strengthen a broken spine bone weakened by osteoporosis or cancer.
In simple terms: A procedure where medical cement is injected into a broken spine bone to stabilize it.

vesicoureteral

From the bladder to the ureter; may involve abnormal urine backflow into the ureter.
In simple terms: Urine going the wrong way—from the bladder back toward the kidney.

video capsule endoscopy

A procedure where a patient swallows a tiny camera that records images of the small intestine.
In simple terms: A pill with a camera that takes pictures inside the digestive system.

virtual private network (VPN)

A computer network that uses public connections but protects data through encryption.
In simple terms: A secure internet connection used to protect sensitive data.

volumetric modulated arc therapy (VMAT)

An advanced form of radiation therapy delivering a targeted 3D dose to a tumor.
In simple terms: A precise type of radiation treatment that rotates around the body to aim at the tumor.

W

warfarin

Also called Coumadin®. One of a class of medications called anticoagulants, or blood thinners. It decreases the clotting ability of the blood.
In simple terms: A medication that helps prevent blood clots—it makes the blood thinner.

white blood cells

Also known as lymphocytes. Cells that circulate in the blood and fight infection by attacking foreign invaders.
In simple terms: Blood cells that protect the body from germs and illness.

wire localization

Guided by imaging (such as MRI), a thin wire is inserted through a needle into a suspicious area of tissue to mark it for surgical removal.
In simple terms: A wire placed in the body using imaging to help doctors find and remove abnormal tissue during surgery.

X

x-ray (X-Ra)

Ionizing electromagnetic radiation used for imaging. Radiation produced by atomic changes. Or, a radiograph (the image itself).
In simple terms: A kind of invisible energy used to take pictures inside the body—commonly used to see bones.

x-ray therapy

A medical specialty that treats abnormal tissue—cancerous or noncancerous—using x-rays or radioactive substances.
In simple terms: Using x-rays to treat cancer or other abnormal tissue.

Y

Yttrium Y-90

A radioactive form of yttrium used in radiation therapy and immunotherapy.
In simple terms: A type of radiation used to treat certain cancers.

Z

Zevalin®

A Yttrium-90 agent used in radioimmunotherapy to treat non-Hodgkin lymphoma.
In simple terms: A treatment that combines radiation and immune therapy to fight a type of lymphoma.