DIAGNOSIS OF ACUTE FLANK PAIN - VALUE OF UNENHANCED HELICAL CT

OBJECTIVES, The purpose of our study was to determine the value of une nhanced CT in the diagnosis of acute flank pain. We determined the acc uracy of unenhanced CT for stone detection as well as the detection of abnormalities unrelated to stone disease. MATERIALS AND METHODS, Duri ng an 18-month interval, 292 patients with acute flank pain were image d with unenhanced CT, Confirmation of the CT diagnosis was obtained fo r 210 patients: One hundred patients were proved to have ureteral ston es based on other imaging studies (58 patients), lithotripsy (seven pa tients), ureteroscopic stone extraction (five patients), and stone rec overy (30 patients), One hundred ten patients were proved not to have ureteral stones based on other imaging studies (24 patients), failure to recover a stone (56 patients), or a confirmed diagnosis unrelated t o stone disease (30 patients), This latter group of 30 patients includ ed diagnoses of adnexal masses (eight patients), appendicitis (five pa tients), diverticulitis (four patients), and common bile duct stones ( three patients), as well as other diagnoses, RESULTS. Unenhanced CT fi ndings were falsely negative for stone disease in three patients and f alsely positive for stone disease in four patients,These data yield a sensitivity of 97%, a specificity of 96%, and an accuracy of 97% for d iagnosing ureteral stone disease. Of 31 patients with a CT abnormality unrelated to stone disease, there was one false-negative diagnosis of acute appendicitis, CONCLUSION, Unenhanced CT is a valuable technique for examining patients with acute flank pain in whom a clinical diagn osis is uncertain, It can accurately determine the presence or absence of ureteral stones as well as extraurinary causes of acute flank pain , In most cases, other imaging studies are not required.