COLOR AND POWER DOPPLER IMAGING OF THE KIDNEYS

Sonography is a widely used modality for the evaluation of both native and transplanted kidneys. It is noninvasive, portable, and requires m inimal patient preparation. Renal sonography can estimate kidney size, determine the presence or absence of hydronephrosis, and the presence and characteristics of any intrarenal or extrarenal masses. The addit ion of color, and, more recently, power Doppler have enhanced the diag nostic capabilities of renal sonography. Color and power Doppler have distinct but complementary uses, and knowledge of the advantages and l imitations of each are essential for proper application of these power ful tools. The differences between color and power Doppler is discusse d, with emphasis on their relative strengths. Clinical uses of color D oppler include the evaluation of perfusion abnormalities, renal artery stenosis, renal vein thrombosis, pseudoaneurysms, and arteriovenous f istulas. Color and power Doppler are also helpful in the evaluation of the transplanted kidney and can suggest the presence of transplant re jection. The sonographic color and power Doppler features of disease e ntities which affect the kidneys are discussed. Knowledge of these son ographic features will enable prompt diagnosis, thereby expediting pat ient care.