Evaluation of Residual Stone Fragments Following Lithotripsy: Sonography v Radiography

Abstract

The sensitivity of sonography for the detection of residual renal calculi following lithotripsy was compared with the ability to identify stone fragments using radiography (KUB). Following extracorporeal piezoelectric lithotripsy, patients were evaluated with a 3.5 MHz real-time Diasonics ultrasound unit and the ultrasound monitoring system of the Wolf Piezolith 2300 lithotripter. Ultrasonography was performed independently by a radiologist, and by the urologist who had performed the lithotripsy treatment.

Following the ultrasound examination, a KUB was obtained for each patient. All scans and radiographs were reviewed independently by both urologists and radiologists in a blinded fashion, and the results were correlated.

Sonography enabled the detection of the majority of residual renal calculi, with the ability of the urologists to utilize sonography comparing favorably to that of the radiologists. However, because of inherent limitations of sonography, radiography remains a complementary means of identifying residual stone fragments after lithotripsy treatment.

Supported by USPHS Training Grant #5T32-DK07307.