There is also a significant degree of overlap among the reported diagnostic accuracies of tests. Studies differ in case mix, specific test characteristics and cut-off points of positive

test results, all of which may affect estimates GSK2126458 of test performance. There are no randomized controlled trials reported in this area. There are three meta-analyses4,12,13 and two prospective comparative studies.14,15 These studies fulfilled the following predefined criteria to allow assessment of comparative test performance: 1 suspected RVHT was the indication These studies form the basis for the formulation of this subtopic. A high quality meta-analysis by Williams et al.13 examined 88 studies involving 9974 arteries in 8147 patients. The data were analysed according to a hierarchical summary receiver-operating

characteristic (ROC) curve model (Tables 1,2). Heterogeneity in test performance relating to population and design features were ABT-263 purchase also investigated. The following four parameters were evaluated – peak systolic velocity (21 studies), acceleration time (13 studies), acceleration index (13 studies) and renal aortic ratio (13 studies). It was concluded that duplex sonography is a moderately accurate test for RAS and that single peak systolic velocity has the highest performance characteristics, with expected sensitivity of 85% and specificity of 92%. Additional measurements did not increase accuracy. The meta-analysis performed by Vasbinder et al.4 included five studies16–20 that met the predefined inclusion criteria. In three studies, the assessment was blinded. Overall sensitivities Loperamide and specificities ranged from 94% to

100% and 92–99%, respectively. The area under the ROC curve for CTA was 0.99 (Table 3). The meta-analysis by Tan et al.12 identified 39 studies, of which 25 met inclusion criteria. The number of patients included in the meta-analysis was 998: 499 with non-enhanced MRA and 499 with gadolinium-enhanced MRA. The sensitivity and specificity of non-enhanced MRA were 94% (95% confidence interval (CI): 90–97%) and 85% (95% CI: 82–87%), respectively. For gadolinium-enhanced MRA sensitivity was 97% (95% CI: 93–98%) and specificity was 93% (95% CI: 91–95%). Thus, specificity and positive predictive value were significantly better for gadolinium-enhanced MRA (P < 0.001). Accessory renal arteries were depicted better by gadolinium-enhanced MRA (82%; 95% CI: 75–87%) than non-gadolinium MRA (49%; 95% CI: 42–60%) (P < 0.001). It was concluded that MRA with gadolinium enhancement is highly sensitive and specific for diagnosis of RAS (Table 4). Vasbinder et al.4 in their meta-analysis involving 16 studies on MRA demonstrated that gadolinium-enhanced MRA had the highest diagnostic performance. The area under the summary ROC curve for gadolinium-enhanced MRA was 0.