Ultrasound Glossary

A congenital brain abnormality involving the cerebellum and the fourth ventricle, detectable on prenatal and neonatal ultrasound.

The area immediately beneath the ultrasound transducer where structures cannot be clearly imaged due to the initial pulse of sound.

A unit of measurement used to describe the relative loudness or intensity of sound waves, including the ultrasound signals used in diagnostic imaging.

A blood clot in a deep vein, most commonly in the leg — diagnosed with compression ultrasound.

An abnormal shape or structure of a body part that can be congenital or acquired, sometimes assessable with ultrasound imaging.

A condition in which spinal discs gradually break down with age, potentially causing pain and nerve compression, sometimes evaluated with ultrasound.

The gradual wearing down of joint cartilage, also known as osteoarthritis, which can be assessed with musculoskeletal ultrasound.

A condition in which the stomach takes too long to move food into the small intestine, which can be assessed with real-time ultrasound.

An abnormal electrical signal in the heart caused by an extra conduction pathway, which can affect Doppler flow patterns seen during echocardiography.

A type of ovarian tumor that can contain hair, teeth, skin, and other tissues, with a characteristic appearance on ultrasound.

A chronic metabolic disease affecting blood sugar regulation that has many complications detectable and monitorable with ultrasound.

Kidney damage caused by long-term diabetes that can be monitored with renal ultrasound.

The dome-shaped muscle separating the chest from the abdomen that is the primary muscle of breathing, visible on ultrasound as a bright, curved line.

A condition in which abdominal organs push through a hole in the diaphragm into the chest cavity, detectable on prenatal ultrasound.

The phase of the cardiac cycle when the heart muscle relaxes and the chambers fill with blood.

A condition in which the heart’s lower chambers cannot relax and fill with blood normally, diagnosed primarily through echocardiography.

Blood flow that occurs during the relaxation phase of the cardiac cycle, whose presence and pattern provide important diagnostic information on Doppler ultrasound.

The lower number in a blood pressure reading, representing the pressure in the arteries when the heart is relaxing between beats.

A broad term for conditions affecting the entire liver, including fatty liver, hepatitis, and cirrhosis, which alter the liver’s ultrasound appearance.

Disease affecting the functional tissue of an entire organ, causing widespread changes visible on ultrasound.

An X-ray-based imaging technique that creates detailed pictures of blood vessels by subtracting background bone and tissue, used as a reference standard for vascular ultrasound.

The widening or stretching of a hollow organ or tubular structure beyond its normal size, a common finding reported in many ultrasound examinations.

A heart muscle disease in which the heart chambers enlarge and the pumping function weakens, diagnosed primarily through echocardiography.

Inflammation or infection of small pouches in the colon wall, which can sometimes be diagnosed with ultrasound as an alternative to CT scanning.

A condition in which small pouches form in the walls of the colon, present in many adults over age 50, sometimes visible on abdominal ultrasound.

A small pouch or sac that protrudes outward from the wall of a hollow organ, most commonly the colon or bladder.

The angle between the ultrasound beam and the direction of blood flow, which must be 60° or less for accurate velocity measurements.

The change in frequency of sound waves when there is relative motion between the sound source and the listener, which is the fundamental principle behind Doppler ultrasound.

The difference between the transmitted and received ultrasound frequency caused by blood cell movement, used to calculate flow velocity.

An ultrasound technique that detects the movement of blood or tissue by measuring frequency shifts in reflected sound waves.

Systematic evaluation of the shape, velocity, and pulsatility of spectral Doppler waveforms to characterize normal and abnormal flow patterns.

A prenatal ultrasound finding showing two fluid-filled areas in the fetal abdomen, indicating a blockage in the upper small intestine.

An early pregnancy ultrasound finding that helps confirm the gestational sac is located inside the uterus rather than being an ectopic pregnancy.

A genetic condition caused by an extra copy of chromosome 21, which can be screened for with prenatal ultrasound markers.

A fetal blood vessel connecting the pulmonary artery to the aorta that normally closes shortly after birth.

A fetal blood vessel that shunts oxygen-rich blood from the umbilical vein directly to the heart, evaluated during first trimester screening.

A congenital condition in which the duodenum is completely blocked, diagnosed prenatally by the double bubble sign on ultrasound.

The first and shortest segment of the small intestine, connecting the stomach to the jejunum, and an important structure in abdominal ultrasound.

A congenital variant in which a kidney has two separate collecting systems, each with its own ureter, detectable on ultrasound.

An ultrasound examination that combines B-mode imaging with Doppler flow analysis to evaluate both the structure and blood flow of vessels simultaneously.

The combination of anatomical imaging and Doppler blood flow assessment in a single ultrasound examination.

Painful menstrual cramps that can be caused by conditions like endometriosis and adenomyosis, which are evaluated with pelvic ultrasound.

Abnormal development or growth of cells, tissues, or organs that can be detected prenatally or on postnatal ultrasound examinations.

The medical term for difficulty breathing or shortness of breath, a common symptom that may prompt echocardiographic or lung ultrasound evaluation.

An echocardiographic measurement of the distance between the mitral valve and the ventricular septum, used as a quick indicator of heart pumping function.

Ultrasound imaging of the heart to evaluate cardiac structure, function, and hemodynamics.

The relative brightness of a tissue on ultrasound, determined by how strongly it reflects sound waves back to the transducer.

Abnormal widening or dilation of a tubular structure, such as a blood vessel or duct.

The displacement of an organ or tissue from its normal anatomical position, which may be discovered on ultrasound examination.

A pregnancy implanted outside the uterine cavity, most commonly in the fallopian tube — a life-threatening emergency diagnosed on transvaginal ultrasound.