Ultrasound Glossary

One of two slender tubes that connect the ovaries to the uterus, through which eggs travel after ovulation, sometimes visible on ultrasound.

An abnormal channel created within the wall of a blood vessel when blood forces its way between the layers of the vessel wall during a dissection.

The region beyond the focal zone where the ultrasound beam begins to diverge, reducing lateral resolution.

Focused Assessment with Sonography for Trauma — a rapid bedside ultrasound protocol to detect free fluid and pericardial effusion in trauma patients.

The accumulation of fat within the cells of an organ, most commonly the liver, which changes its appearance on ultrasound.

Accumulation of fat within liver cells, appearing as increased echogenicity of the liver parenchyma on ultrasound.

The major artery of the thigh that supplies blood to the leg, one of the most important vessels evaluated in peripheral arterial ultrasound.

The ball-shaped top of the thighbone that fits into the hip socket, a key structure evaluated in infant hip ultrasound.

The narrow section of the thighbone connecting the femoral head to the shaft, commonly affected by fractures in elderly patients.

The major deep vein of the thigh that carries blood back to the heart, one of the most commonly evaluated vessels in venous ultrasound.

The thighbone, the longest and strongest bone in the body, whose length is measured as a standard part of obstetric ultrasound.

A standard ultrasound measurement of the fetal thighbone used to estimate gestational age and calculate fetal weight.

Standardized ultrasound measurements of the fetus used to estimate gestational age, assess growth, and calculate estimated fetal weight.

The unique pattern of blood flow in an unborn baby that bypasses the lungs and uses the placenta for oxygen exchange.

A specialized ultrasound examination of the fetal heart used to detect congenital heart defects before birth.

A condition in which a fetus does not grow to its expected size during pregnancy, monitored closely with serial ultrasound examinations.

The number of times the fetal heart beats per minute, normally between 110 and 160 beats per minute, assessed during every obstetric ultrasound.

A condition in which the fetus grows significantly larger than average, increasing the risk of delivery complications.

The earliest visible form of the developing embryo on ultrasound, appearing as a small, thickened area adjacent to the yolk sac.

The part of the fetus that overlies the maternal cervix, most commonly cephalic (head down) — assessed on obstetric ultrasound.

A common, benign tumor of the uterine muscle, also called a leiomyoma, that is one of the most frequent findings in pelvic ultrasound.

A benign tumor made of fibrous connective tissue that can occur in various locations throughout the body.

A non-inflammatory arterial disease that causes abnormal growth of cells in the artery wall, leading to narrowing, and detectable with Doppler ultrasound.

The formation of excess scar tissue in an organ, which increases its stiffness and can be assessed with ultrasound elastography.

The first 12 weeks of pregnancy, during which early ultrasound confirms viability, dates the pregnancy, and screens for certain abnormalities.

A combination of ultrasound measurements and blood tests performed between 11 and 14 weeks to assess the risk of chromosomal abnormalities.

An abnormal connection between two body structures that are not normally connected, which can sometimes be detected or evaluated with ultrasound.

Any abnormal accumulation of fluid within the body, appearing as a dark area on ultrasound that may represent blood, pus, bile, or other fluids.

The depth at which the ultrasound beam is narrowest and lateral resolution is best.

A rapid, bedside ultrasound examination performed on trauma patients to detect free fluid in the abdomen, chest, and around the heart.

A small, fluid-filled sac in the ovary that contains a developing egg, visible on ultrasound as a round, dark structure.

A reproductive hormone that stimulates the growth of ovarian follicles, whose effects are monitored with ultrasound during fertility treatment.

A common, benign ovarian cyst that forms when a follicle fails to release its egg and continues to grow, usually resolving on its own.

A soft spot on an infant’s skull where the bones have not yet fused, used as an acoustic window for brain ultrasound.

The large opening at the base of the skull through which the spinal cord connects to the brain.

A normal opening between the left and right atria of the fetal heart that allows blood to bypass the lungs before birth and usually closes after delivery.

Any object that is not naturally present in the body, such as a splinter, piece of glass, or retained surgical material, which can be located with ultrasound.

A standard ultrasound image of the fetal heart showing all four chambers, used to screen for congenital heart defects during prenatal ultrasound.

The number of complete ultrasound images produced per second, which affects how smoothly moving structures appear on the display.

Fluid that moves freely within a body cavity, such as the abdomen or pelvis, which appears as dark areas between organs on ultrasound.

The number of sound wave cycles per second, measured in megahertz (MHz); higher frequency gives better resolution but less penetration.

A type of aneurysm in which the blood vessel bulges symmetrically outward in all directions, creating a spindle-shaped dilation.

Real-time co-registration of ultrasound with a pre-acquired CT or MRI dataset, allowing simultaneous side-by-side or overlaid display for lesion targeting.

The overall amplification of returning ultrasound signals, controlling the overall brightness of the image.

A small, pear-shaped organ beneath the liver that stores and concentrates bile, one of the most commonly examined structures in abdominal ultrasound.

A relatively rare but aggressive cancer of the gallbladder that may appear on ultrasound as a mass replacing the gallbladder or as irregular wall thickening.

Abnormal distension of the gallbladder caused by prolonged obstruction of the cystic duct, resulting in a markedly enlarged, fluid-filled gallbladder.

A growth projecting from the inner wall of the gallbladder that does not move with position changes and does not cast a shadow, unlike gallstones.

A thick, muddy mixture of bile components that settles in the gallbladder, appearing as low-level echoes on ultrasound.

A sonographic finding of increased gallbladder wall thickness (>3 mm), associated with cholecystitis but also many systemic conditions.