Kidney biopsy and power Doppler imaging

Abstract

Practically, all complications of kidney biopsy are connected with hemorrhage. In the last years, the use of color Doppler sonography in monitoring kidney biopsies was being described, later the possibility of using power Doppler (PD) in performing kidney biopsies was presented. PD depicts the amplitude, or power, of Doppler signals rather than the frequency shift. This allows detection of a larger range of Doppler shifts and thus better visualization of small vessels, but at the expense of directional and velocity information. Biopsy of native kidneys was performed in 144 patients. We performed real-time ultrasound-guided biopsy with an automatic biopsy device, 2-4 MHz convex probe and modified 18 G tru-cut needles were used. The vessels in the region of the biopsy were imaged with color Doppler sonography and with PD immediately before, after and the day following biopsy. Adequate tissue for histologic diagnosis was obtained in all patients with average 3.28 attempts at biopsy (range from 2-5). Average 24.15 (range from 7-58) glomeruli were obtained during each session. We observed complications in 6 (4.2%) patients, macrohematuria was presented in 4, and small hematoma with no need for intervention in 2 patients. In 138 (95.8%) patients, no complications were observed, microhematuria was present in 116 (80.6%) patients. In our study, complication rate of kidney biopsy was low and no complication requiring intervention was observed. Number of glomeruli obtained during each session was high. For better visualization of kidney vessels in biopsy path, PD was used. This additional kidney investigation itself does not essentially prolong the duration of the biopsy.