Imaging in acute renal colic: the intravenous urogram remains the gold standard

In a prospective study of 150 consecutive patients presenting over a 1-year period with acute renal colic, we compared the accuracy of intravenous urogram (i.v.u.) and ultrasound (US) in identifying and localizing ureteric calculi and hydronephrosis. i.v.u. was far superior to US. It identified 141 ureteric calculi vs. only one by US (P < 0.00001) and 109 hydronephroses vs. 66 (P < 0.0001). It is concluded that i.v.u. remains the gold standard for imaging in acute renal colic. US +/- plain supine abdominal film should be reserved for contrast medium risk patients and those in whom radiation is relatively contraindicated.