Sensitivity of gray scale ultrasound in detecting urinary tract obstruction

TLDR

The study aimed to assess the reliability of gray‑scale ultrasound for detecting urinary tract obstruction in 67 patients. Hydronephrosis was graded by urographic criteria and the ultrasound images were evaluated blinded to urography findings. Ultrasound correctly identified obstruction in 98% of cases, proving it an effective screening test that can reduce the need for excretory urography in many patients.

Abstract

To determine the reliability of gray scale ultrasound in detecting urinary tract obstruction, a prospective study of 67 patients examined by both excretory urography and ultrasound was undertaken. The degree of hydronephrosis was defined by urographic criteria, and the corresponding echograms were analyzed without knowledge of the urographic results. Hydronephrosis was correctly diagnosed by ultrasound in 46 of 47 kidneys shown to be obstructed on urography, for a sensitivity of 98%. Our results show that when obstruction is the sole clinical question, ultrasound is an effective screening test. Thus many patients with a variety of medical diseases of the kidney can be spared excretory urography.