(HU) density and axial stone diameter. Stone volume was calculated on a volumerendered 3D image for each stone. Maximum stone length was determined by comparative measurements of each stone in coronal, sagittal and axial planes, and was also measured on a plain abdominal film before ESWL. For ESWL we used the DoliS lithotripter (Dornier Medical Systems, Marrietta, GA, USA). A plain film at 6 weeks was used to categorize patients as stonefree (SF) or with residual stone. RESULTSIn all, 58 (62%) patients were SF and 36 (38%) had RS; the mean stone volume was significantly different between these groups (274 vs 464 µ L, P = 0.002). Logistic regression analysis showed that stone volume was the strongest predictor of SF status ( P < 0.001), compared to peak HU ( P = 0.015), mean HU ( P = 0.04) and axial stone diameter ( P = 0.006). The body mass index, SSD and maximum stone length on NCCT or a plain film did not predict success. A stone volume of < 500 µ L best predicted treatment success ( P < 0.001) with 72% of patients with a stone volume of < 500 µ L having a successful outcome, vs only 27% with a stone volume of > 500 µ L. CONCLUSIONOur study suggests that stone volume is an optimal predictor of SF status after ESWL of solitary upper urinary tract calculi. KEYWORDSurinary calculi, stone volume, success, shock wave lithotripsy Study Type -Diagnostic (exploratory cohort study) Level of Evidence 2b OBJECTIVETo evaluate the efficacy of stone volume measured using a three-dimensional (3D) reconstruction of preoperative non-contrast computed tomography (NCCT) as an independent predictor of success after extracorporeal shock wave lithotripsy (ESWL) of upper urinary tract calculi. PATIENTS AND METHODSWe evaluated preoperative NCCT in 94 patients who had ESWL for solitary upper urinary tract calculi of 4-20 mm in diameter. Axial images were used to measure the skinto-stone distance (SSD), Hounsfield Unit

The overall detection rate of unsuspected cancer is approximately one per 200 asymptomatic adults undergoing routine screening CT colonography, including about one invasive CRC per 500 cases and one extracolonic cancer per 300 cases. Detection and treatment at an early presymptomatic stage may have contributed to the favorable outcome.

Primary 2D CTC is less sensitive than primary 3D CTC for polyp detection in low-prevalence screening cohorts. The disappointing 2D sensitivity in this study was very similar to results obtained with primary 2D evaluation in previous CTC trials.