Multidetector CT Angiography -: is it a valuable screening tool to detect significant renal artery stenosis?

Purpose: To evaluate the diagnostic value of multidetector CT angiography (MDCTA) of the renal arteries. Methods: 27 patients underwent MDCTA of the renal arteries. Scan parameters were: collimation 4 x 1 mm, pitch 1.5, effective slice thickness 1.25 mm, reconstruction increment 0.8 mm, circulation time measurement, power injection of 80 ml iomeprol 400, flow 4 ml/sec. independent reading on laser film was done by two radiologists using edited maximum intensity projections, multiplanar reconstructions and source images. Standard of reference was a 3D-FLASH MR angiography (1.5T, 3.9/1.2, 10 degrees 0.2mmol GdDTPA/kg bw) in 10 and intraarterial angiography in 17 patients. Results: Analysing 63 arteries, sensitivity, specificity, positive predictive value and negative predictive value in terms of detection of moderate and high grade renal artery stenosis (n = 10) were 90, 98, 90 and 98% for reader A, and 90% each for reader B, respectively (kappa = 0.91 interobserver agreement). 1 ill I acessory renal arteries was missed by both angiography and MDCTA. Image quality was graded as excellent or good in 26/27 of cases by both readers. Conclusion: MDCTA proved to be a highly accurate tool in the detection of therapeutically relevant renal artery stenosis.