Comparative analysis and interobserver variation of unenhanced computed tomography and intravenous urography in the diagnosis of acute flank pain

The purpose of this study was to compare unenhanced computed tomography [UECT] to intravenous urography [IVU] for detecting urinary tract calculi, signs of obstruction and non-renal causes in the assessment of acute flank pain, and in their interobserver agreement. In this prospective study, carried out at a university hospital over a period of 1 year, 36 patients [27 males and 9 females] participated. Mean age was 44 +/- 15 years [range: 14-73 years].The patients presented with acute flank pain and underwent UECT and IVU. The images were blindly evaluated by 2 experienced radiologists and the two techniques compared using the two-tailed McNemar's test for matched pairs; p values <0.05 were considered significant. UECT detected stones in 11 [30.6%] patients, while IVU found them in only 8 [22.2%]. The increased detection by UECT was due to its ability to detect smaller stones [<6 mm]. UECT was also found to be better than IVU in determining calculus position, in detecting primary or secondary signs of obstruction and in identifying non-urinary causes of flank pain. The overall average of agreement as indicated by kappa values, was 0.88 for UECT and 0.61 for IVU. UECT showed better detectability and interobserver agreement than IVU, suggesting that UECT could replace IVU as the first imaging modality in the evaluation of acute renal colic

Accuracy of 64-multidetector-row computed tomography in the diagnosis of coronary artery disease

The aim of this prospective study was to assess the accuracy of 64-multidetector-row computed tomography coronary angiography [CTA] in the diagnosis of coronary artery disease [CAD Ninety-two patients suspected of having CAD underwent CTA using a 64-slice CT scanner before a scheduled, conventional coronary angiogram [CCA]. Blinded assessment of CTA to detect CAD was performed. The accuracy of CTA in detecting significant stenoses [>/= 50%] was compared to CCA. Data analysis was performed on 73 patients because the scans were nondiagnostic in 5 patients and 14 refused to undergo coronary angiography The CTAs of 21 of these 73 patients were considered as normal; 19 were confirmed on CCA. For the remaining 52 diagnosed as abnormal, 51 were confirmed on CCA. For patient-based analysis, CTA had a sensitivity of 95%, a specificity of 96%, a positive predictive value of 98% and a negative predictive value of 90%. For the whole vessel, the sensitivity of CTA was 60-100%, for all vessels and the specificity was 82-100%. Pooled sensitivity was 92% and pooled specificity was 98%. For the segments, the sensitivity of CTA was 64% or above for all vessels except for the distal left anterior descending artery [40%], mid circumflex artery [50%] and posterior descending artery [60%]; the pooled sensitivity was 79%. The specificity for the segments was 82-100% for all vessels and pooled specificity was 94%. The sensitivity and specificity for patient-based analysis and for the main coronary vessels were high whereas for the segments, the sensitivity was moderately good, but the specificity was high, confirming that a negative CTA is useful to rule out significant CAD. A coordinated classification system between radiologists and cardiologists is required to eliminate errors in segment classification