Localization of the Kidney for Percutaneous Biopsy

Intravenous pyelography, radionuclide scan, and ultrasonography were compared to image-amplification fluoroscopy in 48 patients to assess the accuracy of each technique in determining renal size and lower pole position. The reliability of ultrasonographic renal-depth prediction for biopsy was also evaluated in 37 patients. Scan and ultrasound delineated renal size accurately, but pyelography showed a marked projection distortion (P <0.001). Ultrasound localized the lower pole most precisely, followed by scan, and pyelography demonstrated poor accuracy. Five cases could be localized only by ultrasound. The correlation of renal depth by ultrasound and exploring needle was highly significant (r = 0.88, P < 0.001). Renal tissue was obtained in 100% of biopsies, cortex in 97%, and tissue adequate for diagnosis in 92%. Ultrasound and scan appear superior to pyelography and comparable to fluoroscopy in accuracy of renal localization. Ultrasound has additional major advantages over the other methods for percutaneous renal biopsy.