Ultrasound Glossary

The largest artery in the body, carrying oxygen-rich blood from the heart to all other organs, and one of the most commonly evaluated structures in abdominal ultrasound.

Permanent dilation of the aorta to 1.5 times its normal diameter or greater — the abdominal aorta is screened with ultrasound in high-risk populations.

The curved upper portion of the aorta that gives rise to the major arteries supplying the head, neck, and arms.

A life-threatening condition in which the inner layer of the aorta tears, allowing blood to flow between the layers of the vessel wall.

A condition in which the aortic valve does not close properly, allowing blood to leak backward into the heart with each beat.

The first section of the aorta as it exits the heart, containing the aortic valve and the origins of the coronary arteries.

A narrowing of the aortic valve that restricts blood flow from the heart to the rest of the body, commonly evaluated with echocardiography.

The valve between the left ventricle and the aorta that opens to let blood flow out of the heart and closes to prevent backflow.

Aortic Valve Area (AVA): Continuity equation-derived functional valve orifice area; severe aortic stenosis = AVA

A standard echocardiographic view obtained at the cardiac apex showing all four cardiac chambers simultaneously.

Inflammation of the appendix, a condition that can be diagnosed using ultrasound, especially in children and pregnant women.

A small, tube-shaped pouch attached to the large intestine in the lower right abdomen, commonly evaluated with ultrasound when appendicitis is suspected.

A fluid-filled sac that develops between the brain and the arachnoid membrane, usually detected incidentally on ultrasound or other brain imaging.

Small projections of the arachnoid membrane that absorb cerebrospinal fluid back into the bloodstream, occasionally visible on neonatal cranial ultrasound.

A small artery in the kidney that runs along the border between the cortex and medulla, visible on Doppler ultrasound.

A fibrous band near the diaphragm that can compress the celiac artery, a condition detectable with Doppler ultrasound.

A minor variation in the shape of the uterus where the top has a slight inward curve, considered a normal variant by most experts.

The American Registry for Diagnostic Medical Sonography — the primary credentialing body for sonographers in the United States.

An abnormal heart rhythm that can be detected during echocardiography or fetal heart rate monitoring with ultrasound.

Arterial Hyperenhancement: Intense contrast enhancement of a lesion during the arterial phase; combined with late-phase washout, it is diagnostic of HCC in cirrhotic livers. Arterial hyperenhancement is the pattern of rapid, intense enhancement of a lesion during the arterial phase of contrast-enhanced ultrasound (CEUS), CT, or MRI, reflecting neovascularity. In the liver, arterial hyperenhancement followed…

An abnormal connection between an artery and vein, recognized on Doppler by high-velocity low-resistance arterial flow and arterialized venous flow.

A tangle of abnormal blood vessels where arteries connect directly to veins without the usual capillary bed in between.

Any feature on an ultrasound image that does not correspond to actual anatomy, produced by the physics of sound propagation.

Abnormal accumulation of free fluid in the peritoneal cavity, readily detected on abdominal ultrasound.

The absence of the spleen, either from birth or after surgical removal, which has important implications for a patient’s immune system.

A disease in which fatty deposits called plaque build up inside artery walls, narrowing the vessels and restricting blood flow.

A deposit of fat, cholesterol, calcium, and cellular debris that accumulates on the inner wall of an artery.

The most common type of irregular heartbeat, in which the upper chambers of the heart quiver chaotically instead of contracting in a coordinated rhythm.

A hole in the wall between the two upper chambers of the heart, which is one of the most common congenital heart defects.

A small cluster of specialized cells in the heart that controls the electrical signal between the upper and lower chambers.

Either of the two heart valves located between the upper and lower chambers, known as the mitral valve on the left and the tricuspid valve on the right.

The progressive loss of ultrasound energy as sound travels through tissue, due to absorption, reflection, and scattering.

An increase in venous blood flow detected by Doppler when a body part below the probe is squeezed, used to test if veins are open and functioning properly.

The mathematical technique used by color Doppler ultrasound machines to rapidly estimate the speed and direction of blood flow.

The ability of an ultrasound system to distinguish between two structures that are stacked one above the other along the path of the sound beam.

The main artery of the armpit region that continues as the brachial artery in the upper arm, evaluated in upper extremity vascular ultrasound.

The main vein draining the arm, located in the armpit, commonly evaluated during upper extremity venous ultrasound.

A vein running along the right side of the spine that drains blood from the chest wall and connects to the superior vena cava.

A bright, vertical artifact on lung ultrasound that extends from the pleural line to the bottom of the screen, indicating fluid in the lung tissue.

Vertical artifacts on lung ultrasound extending to the bottom of the screen, indicating interstitial fluid or pulmonary edema when present in large numbers.

The standard 2D grayscale ultrasound display mode, where echo brightness represents tissue density.

B-Mode is the standard 2D ultrasound image. Learn how B-Mode works, what it shows, and why it’s fundamental to ultrasound imaging.

The most common type of ultrasound that displays a two-dimensional picture of body structures in shades of gray. The brightness of each dot represents the strength of the echo returning from that spot.

A fluid-filled sac that forms behind the knee, usually related to knee joint problems, and is easily seen on ultrasound.

A group of structures deep within the brain that help control movement, visible on neonatal cranial ultrasound.

A major artery at the base of the brain formed by the junction of the two vertebral arteries, assessable with transcranial Doppler.

A vein running along the inner side of the upper arm that is commonly evaluated during upper extremity venous ultrasound.

A phenomenon in which the ultrasound beam becomes progressively weaker and shifts in frequency as it passes through tissue, affecting image quality.

The electronic technique used to direct the ultrasound beam in different directions without physically moving the transducer.

The physical width of the ultrasound beam at any given depth, which affects the lateral resolution and overall image quality.