Ultrasound Glossary

A non-cancerous enlargement of an organ caused by an increase in the number of normal cells, most commonly referring to the prostate gland.

A physics equation used in echocardiography to estimate pressure differences across narrowed heart valves from Doppler velocity measurements.

A measurement used in infant hip ultrasound to assess the cartilage roof of the hip socket.

Breast Imaging Reporting and Data System — a standardized classification for breast ultrasound findings guiding management decisions.

BI-RADS (Breast Imaging Reporting and Data System): ACR standardized reporting system for breast imaging; ultrasound categories 0–6 guide clinical management from routine screening to biopsy recommendation. BI-RADS is the ACR standardized lexicon and reporting system for breast imaging including ultrasound, mammography, and MRI. Ultrasound BI-RADS categories range from 0 (incomplete) to 6 (known malignancy). Key…

A large muscle on the back of the thigh that is part of the hamstring group and can be evaluated with musculoskeletal ultrasound.

A heart-shaped uterus with two separate upper cavities joined at the lower segment, caused by incomplete fusion during fetal development.

A congenital heart defect in which the aortic valve has two leaflets instead of the normal three, affecting about 1 to 2 percent of the population.

A medical term meaning on both sides of the body, commonly used in ultrasound reports to describe findings affecting paired organs or structures.

The tubes that carry bile from the liver and gallbladder to the small intestine, routinely measured during abdominal ultrasound.

Intense, cramping pain in the upper right abdomen caused by a gallstone temporarily blocking the cystic duct or common bile duct.

Enlargement of the bile ducts on ultrasound, indicating obstruction — the common bile duct normally measures less than 6 mm.

A condition in which bile flow slows or stops within the bile ducts or gallbladder, which can lead to sludge formation visible on ultrasound.

A localized collection of bile outside the bile ducts, usually caused by trauma, surgery, or gallbladder rupture.

The biological effects of ultrasound energy on tissue, including thermal and mechanical (cavitation) effects monitored by the TI and MI indices.

The practice of taking standardized measurements of fetal structures during ultrasound to estimate gestational age and assess growth.

A prenatal assessment combining ultrasound observations of fetal movement, tone, breathing, and amniotic fluid with a non-stress test.

A medical procedure in which a small tissue sample is removed from the body for examination, often performed under ultrasound guidance.

A fetal head measurement from the outer edge of one parietal bone to the inner edge of the opposite — used for gestational age and growth assessment.

The hollow, muscular organ that stores urine, commonly imaged with ultrasound and used as an acoustic window for pelvic examinations.

A stone that forms or lodges within the urinary bladder, visible on ultrasound as a bright structure with posterior shadowing that moves with patient positioning.

An outpouching of the bladder wall that can trap urine and lead to infections or stone formation, visible on ultrasound.

A blockage at the base of the bladder that prevents urine from flowing freely into the urethra, commonly caused by an enlarged prostate in men.

An early stage of embryonic development, about five days after fertilization, when the fertilized egg becomes a hollow ball of cells ready to implant in the uterus.

The movement of blood through the cardiovascular system, assessed in ultrasound using Doppler techniques that measure the speed and direction of flowing blood.

A dose of contrast agent or medication injected quickly into a vein, sometimes used during specialized ultrasound examinations.

A blockage in the small or large intestine that prevents food and fluid from passing through, detectable with ultrasound in many cases.

The main artery of the upper arm, extending from the axilla to the elbow, where it splits into the radial and ulnar arteries.

A network of nerves originating from the neck and running through the shoulder that controls movement and sensation in the arm.

A deep vein of the upper arm that runs alongside the brachial artery and is evaluated during upper extremity venous duplex examinations.

The first and largest branch of the aortic arch, which divides into the right common carotid artery and the right subclavian artery.

An abnormally slow heart rate, generally defined as fewer than 60 beats per minute in adults or below the normal range for a fetus.

The lower portion of the brain connecting to the spinal cord, controlling vital functions like breathing and heart rate, visible on neonatal cranial ultrasound.

The most common benign breast tumor, appearing on ultrasound as a smooth, well-defined, oval mass that is wider than it is tall.

An abnormal whooshing sound heard with a stethoscope over a blood vessel, indicating turbulent flow that can be further evaluated with Doppler ultrasound.

Tiny gas-filled microspheres injected into the bloodstream to enhance ultrasound images of blood vessels and organ perfusion.

A collection of specialized heart cells that transmits electrical signals from the upper chambers to the lower chambers of the heart.

A small, fluid-filled sac that cushions areas where bones, tendons, and muscles move against each other, easily evaluated with musculoskeletal ultrasound.

Inflammation of a bursa, causing pain and swelling near a joint, which is clearly visible and characterizable with musculoskeletal ultrasound.

The heel bone, the largest bone of the foot, which can be evaluated with musculoskeletal ultrasound for injuries and inflammation.

A deposit of calcium within body tissues that appears bright white on ultrasound and typically casts an acoustic shadow.

A hard, stone-like deposit that forms in organs or ducts, such as gallstones in the gallbladder or kidney stones in the urinary tract.

Enlargement of the cup-shaped structures in the kidney that collect urine, an early sign of urinary obstruction visible on ultrasound.

One of the small, cup-shaped structures in the kidney that collects urine from the kidney tissue and channels it toward the renal pelvis.

Cardiac refers to the heart. Learn about cardiac anatomy, cardiac disease, and cardiac sonography (echocardiography).

One complete sequence of heart contraction and relaxation, consisting of systole and diastole, which is the foundation of all echocardiographic measurements.

The total volume of blood pumped by the heart per minute, calculated using echocardiographic measurements of stroke volume and heart rate.

A life-threatening condition in which fluid accumulates in the sac around the heart, compressing it and preventing it from filling properly.

A blood clot that forms inside one of the heart chambers, which can be detected by echocardiography and may break loose to cause a stroke.

An enlarged heart, which can be detected and measured using echocardiography and may indicate underlying heart disease.