Ultrasound Glossary

A condition in which the flow of bile from the liver is slowed or blocked, which may cause bile duct dilation visible on ultrasound.

Thin, cord-like structures that connect the heart valve leaflets to the papillary muscles, preventing the valves from turning inside out during contraction.

End-stage liver fibrosis characterized on ultrasound by a coarsened echotexture, nodular surface, and signs of portal hypertension.

A clinical rotation is hands-on training where students perform real ultrasound exams under supervision. Learn about clinical rotations in sonography programs.

Cogwheel Sign: Cross-sectional ultrasound appearance of an inflamed fallopian tube with echogenic mucosal folds projecting inward, characteristic of pyosalpinx in PID. The cogwheel sign is a sonographic finding seen in pelvic inflammatory disease (PID) on transvaginal ultrasound in which the inflamed fallopian tube appears as a circular structure with internal echogenic projections (incomplete septa or…

A Doppler mode that overlays color-coded blood flow direction and velocity onto a 2D B-Mode image in real time.

An ultrasound technique that displays blood flow as colors on top of a grayscale image. Red typically means blood flowing toward the transducer and blue means blood flowing away.

A Doppler mode using two crystals to continuously transmit and receive, capable of measuring very high blood flow velocities without aliasing.

An imaginary line that divides the body from top to bottom, creating front and back halves. A coronal scan shows a front view of the body.

A temporary endocrine structure formed in the ovary after ovulation, appearing on ultrasound as a thick-walled cystic structure with peripheral vascularity.

The measurement from the top of the fetal head to the bottom of the torso, used to date a pregnancy in the first trimester.

A transducer with a curved face that produces a fan-shaped image, used for abdominal and obstetric imaging.

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.

Deep vein thrombosis is a blood clot in a deep leg vein. Learn about DVT risk factors, symptoms, and ultrasound diagnosis.

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.

Doppler is an ultrasound technique that measures blood flow and velocity. Learn how Doppler works, its types, and clinical applications.

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.