B-mode ultrasound and the nonvisualizing kidney in pediatrics.

Ultrasonic definition of the kidney is independent of renal function and therefore capable of imaging impaired or dysplastic renal tissue, In 28 cases, B-mode scanning delineated one or both kidneys which failed to visualize during intravenous pyelography. Similar imaging of both kidneys was obtained in 10 cases of renal failure in which intravenous pyelography was not attempted. The presence and relative severity of hydronephrosis was established. In three cases of multicystic kidney, a diagnostic appearance was elicited. In these instances, in one additional case of renal dysplasia, and in three cases of severe obstructive uropathy, sonography provided the only presurgical definition of the abnormal kidney. Suspected kidney enlargement was rapidly confirmed in a case of renal vein thrombosis and excluded in a case of chronic renal failure. In both instances hydronephrosis was excluded. In 12 of the 38 cases, ultrasonic guidance was utilized for percutaneous renal biopsy.