Detection of renal calculi: the value of tomography

Two hundred patients were evaluated to determine the sensitivity of tomography in detecting calculous disease of the upper urinary tract. In all cases, patients had routine scout radiographs of the abdomen and five precontrast tomograms of the kidneys. Of the 200 patients, 28 (14%) had renal calculi. Of these, 11 (39%) had either unsuspected or more calculi detected on tomography than seen on abdominal radiographs. Patients with symptoms suggestive of calculous disease should be evaluated with tomography in addition to plain films in order to optimize the detection and the extent of calculous disease involving the urinary tract.