Ultrasound Glossary

The spleen is an immune and blood-filtering organ in the left upper abdomen, routinely evaluated by ultrasound for size, texture, and focal lesions.

The splenic artery is the tortuous vessel that carries blood from the celiac trunk to the spleen, visible on abdominal ultrasound.

The splenic vein carries blood from the spleen to the portal vein, evaluated by ultrasound for thrombosis and dilation.

Enlargement of the spleen beyond its normal size, measured on ultrasound by craniocaudal length.

Stenosis is the abnormal narrowing of a body passage, frequently evaluated in blood vessels and heart valves by Doppler ultrasound.

String-of-Pearls Sign: Ultrasound pattern in PCOS of multiple 2–9 mm peripheral follicles arranged around the ovarian stroma, resembling a string of pearls. The string-of-pearls sign is a sonographic pattern in polycystic ovary syndrome (PCOS) where multiple small follicles (2–9 mm) are arranged peripherally in the ovary, resembling a necklace of pearls. It reflects arrested follicular…

The subclavian artery is a major vessel supplying the arm and parts of the brain, assessed by Doppler ultrasound for stenosis and steal syndrome.

The subclavian vein is a major vein beneath the collarbone, evaluated by ultrasound for thrombosis and used as a landmark for central venous access.

An ultrasound imaging plane obtained by placing the transducer below the ribcage, used in echocardiography and FAST exams.

A subdural hematoma is a collection of blood between the brain and its outer covering, sometimes detectable by transcranial ultrasound in infants.

The superior mesenteric artery is a major abdominal vessel supplying most of the small intestine and part of the colon, evaluated by Doppler ultrasound.

The superior mesenteric vein drains blood from the small intestine and colon, joining the splenic vein to form the portal vein.

The superior vena cava is the large vein returning blood from the upper body to the heart, partially visible on echocardiography.

Synovial fluid is the lubricating liquid within joints, visible on ultrasound when increased due to inflammation or injury (joint effusion).

Tachycardia is an abnormally fast heart rate, which can be identified and evaluated using echocardiography and fetal ultrasound.

A fibrous connective tissue structure that attaches muscle to bone, appearing as a fibrillar hyperechoic band on ultrasound.

Tendonitis is inflammation or degeneration of a tendon, appearing on ultrasound as tendon thickening and loss of normal echogenic texture.

A teratoma is a tumor containing multiple tissue types such as hair, fat, and teeth, appearing as a complex, echogenic mass on ultrasound.

Testicular carcinoma is cancer of the testicle, typically presenting as a solid, hypoechoic intratesticular mass on ultrasound.

A urologic emergency caused by twisting of the spermatic cord, diagnosed on Doppler ultrasound by absent testicular blood flow.

The testis is the male reproductive gland that produces sperm and testosterone, routinely evaluated by scrotal ultrasound.

A real-time display on ultrasound machines estimating the potential for tissue heating from the ultrasound beam.

Thrombosis is the formation of a blood clot within a blood vessel, detected by ultrasound through non-compressibility and absent Doppler flow.

The thyroid is a butterfly-shaped gland in the neck that regulates metabolism, commonly evaluated by ultrasound for nodules, size, and texture.

Thyroid carcinoma is cancer of the thyroid gland, characterized on ultrasound by suspicious nodule features like microcalcifications and irregular margins.

A thyroid nodule is a growth within the thyroid gland, assessed by ultrasound for size, characteristics, and cancer risk using the TI-RADS system.

Thyroiditis is inflammation of the thyroid gland, appearing on ultrasound as a diffusely heterogeneous and hypoechoic thyroid.

An amplification adjustment that increases gain for echoes returning from greater depths to compensate for attenuation.

Thyroid Imaging Reporting and Data System — a standardized ultrasound classification system for thyroid nodules to guide biopsy decisions.

TIRADS (Thyroid Imaging Reporting and Data System): ACR standardized classification for thyroid nodule ultrasound features; TR1–TR5 risk categories guide FNA biopsy decisions based on malignancy suspicion. TIRADS is a standardized ultrasound classification system for thyroid nodules that stratifies malignancy risk and guides fine-needle aspiration (FNA) biopsy decisions. The ACR TIRADS assigns points for composition, echogenicity,…

Tissue harmonic imaging is an ultrasound technique that uses harmonic frequencies generated within the body to produce clearer images with fewer artifacts.

Transabdominal ultrasound is the standard approach of scanning through the abdominal wall to image internal organs and the developing fetus.

Doppler ultrasound of the intracranial arteries performed through the temporal bone window, used to detect stenosis, emboli, and vasospasm.

The handheld probe that transmits and receives ultrasound waves, converting electrical energy to sound and back.

A transducer is the ultrasound probe that sends and receives sound waves. Learn about transducer types, frequencies, and how they work.

Transesophageal echocardiography (TEE) is an ultrasound technique where a probe is passed into the esophagus to obtain detailed images of the heart from behind.

An ultrasound technique using an endocavitary probe placed in the vagina for high-resolution pelvic imaging.

An imaginary line that divides the body from left to right, creating top and bottom halves. A transverse scan shows a top-down view of the body and is also called an axial scan.

An ultrasound scan taken across the width of a structure, showing how wide it is. Transverse scans show the body from side to side and help you see cross-sections of organs.

Tricuspid regurgitation is backward leaking of blood through the tricuspid valve, evaluated by Doppler echocardiography.

The tricuspid valve is the three-leaflet heart valve between the right atrium and right ventricle, assessed on echocardiography.

A tubo-ovarian abscess is an infected mass involving the fallopian tube and ovary, appearing as a complex pelvic collection on ultrasound.

A tumor is an abnormal mass of tissue that can be benign or malignant, evaluated by ultrasound for size, characteristics, and blood flow.

A rapidly flickering color Doppler signal seen behind strongly reflective surfaces such as kidney stones, improving their detection.

Microbubble-based agents injected intravenously to enhance Doppler and tissue perfusion assessment on ultrasound.

The umbilical arteries are two vessels in the umbilical cord that carry deoxygenated blood from the fetus to the placenta, assessed by Doppler for fetal well-being.

Doppler evaluation of blood flow in the umbilical arteries to assess placental resistance and fetal well-being in high-risk pregnancies.

The connecting structure between fetus and placenta, containing two arteries and one vein — evaluated on obstetric ultrasound.

The umbilical vein is the single vessel in the umbilical cord carrying oxygen-rich blood from the placenta to the fetus.

The ureter is the tube that carries urine from the kidney to the bladder, partially visualizable on ultrasound when dilated.