Plain abdominal radiography with transabdominal native tissue harmonic imaging ultrasonography vs unenhanced computed tomography in renal colic

OBJECTIVE: To compare plain film kidney, ureter and bladder radiography (KUB) with transabdominal native tissue harmonic imaging ultrasonography (NTHI-US) vs unenhanced computed tomography (CT) for the diagnosis of urinary calculi in patients with acute flank pain. PATIENTS AND METHODS: In all, 112 patients who presented to the urological department with clinical suspicion of ureteric calculi were included. These patients had KUB with NTHI-US and unenhanced CT. Of the 112 patients, 14 were lost to follow-up and therefore excluded. For the remaining 98 patients (53 men, 45 women; mean age 43.3 years, range: 19-74) the KUB with NTHI-US findings were compared with the CT findings, which served as the 'gold standard'. RESULTS: In all, 75 patients were confirmed to have ureteric calculi. KUB with transabdominal NTHI-US detected 72 of the 75 patients with calculi (sensitivity 96%, specificity 91%, and accuracy 95%). Unenhanced CT detected urolithiasis in all 75 patients (sensitivity, specificity and accuracy of 100%). Both techniques showed further extra-urinary pathologies. CONCLUSION: This prospective study shows that CT is the most accurate technique for detecting urolithiasis. However, KUB with transabdominal NTHI-US is an alternative to unenhanced CT with comparable results.