Noninvasive diagnosis of renal vein thrombosis by ultrasonic echo-Doppler flowmetry

Abstract

Renal vein thrombosis causes structural changes, such as nephromegaly, dilatation of the renal vein due to the thrombus, and the development of collaterals [1, 2]. Diagnosis of renal vein thrombosis by detecting these changes through intravenous pyelography [3, 4] or gray scale ultrasonography [5, 6] has been hampered by the limited resolution of the techniques and the infrequency and variability with which these structural alterations occur, especially in chronic renal vein thrombosis [7], Radiographic demonstration of a persistent filling defect in the vein by either renal venography [8, 9] or by selective renal arteriography during the venous phase [10] are the only definitive procedures available. The diagnosis of renal vein thrombosis has not been attempted by measuring the altered hemodynamics of renal venous blood flow, such as a reduction in the velocity of venous blood flow that is expected to occur proximal to a renal vein thrombus. Recent advances in pulsed Doppler ultrasonic techniques have made it possible to measure flow velocity characteristics in both the normal and the diseased vessels [11–14]. Noninvasive pulsed Doppler flowmetry has not been previously used to study renal veins in humans. The purpose of this study was to assess the feasibility of noninvasively diagnosing thrombosis of renal veins with the use of image-guided high resolution pulsed Doppler flowmetry. Utilizing this method, we measured renal venous blood flow velocity in 12 normal subjects and in 11 patients who had undergone renal venography.