Stenosis refers to the abnormal narrowing of a tubular structure in the body, most commonly a blood vessel or heart valve. In vascular ultrasound, stenosis of arteries such as the carotid, renal, or peripheral arteries is evaluated using Doppler to detect increased blood flow velocities at the site of narrowing — as a passage narrows, blood must move faster to maintain flow volume, similar to water flowing faster through a pinched garden hose. The degree of stenosis is graded based on velocity measurements and ratios. In echocardiography, valve stenosis (aortic, mitral, etc.) is assessed by measuring pressure gradients and valve areas. Identifying and grading stenosis is one of the most important clinical applications of Doppler ultrasound across multiple medical specialties.
Sonography Term