Ultrasonographic diagnosis of renal stones

To illucidate the diagnostic accuracy of ultrasound in the detection of renal stones we performed a blind comparative study of ultrasonography and i.v. urography. In 92 kidneys with 58 stones, 10 stones smaller than 6 mm were overlooked by ultrasound, whereas all stones 6 mm or larger were correctly detected. In one case of uric acid stone disease i.v. urography was inconclusive in determining the true nature of a renal pelvic filling defect, whereas ultrasound correctly diagnosed a stone. We conclude that ultrasonography has a place in diagnosis and control of renal stones.