Application on low-dose unenhanced 16-MDCT in the etiological diagnosis of renal colic

Objective: To retrospectively analyze the application value of low-dose 16-MDCT in the etiological diagnosis of renal colic. Methods: One hundred and six patients (male 68, female 38, mean age of 44) complained of renal colic were enrolled in the study. 16-MDCT scan was performed with the configuration of 1 mm x 16, 120 kV, 60-150 mA, and 0.5s/rot. And curved multiplanar reformation images of the whole ureter were reviewed. Results: Low-dose MDCT scans detected urinary lithiasis in 52 patients with or without ureteral dilation and urinary extravasation but failed to detect a 2 mm diameter ureteral stone in one patient. The sensitivity, specificity, and accuracy of diagnosis of the urinary stone with low-dose 16-MDCT were 98.1%, 100%, and 99.1% respectively. MDCT also detected renal cysts in 18 patients, suspected of tumor in 1 patient and ureteral developmental anomalies in 4 patients. No missed diagnosis was found at follow-up. Conclusion: Low-dose 16-MDCT scanning has a high sensitivity, specificity, and accuracy in diagnosing the urinary stone, and could provide alternative or additional information. (authors)