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 LDK378 in vitro 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 selleck screening library 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 Megestrol Acetate 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.