Comparing diagnostic techniques of magnetic resonance angiography (MRA) and Doppler ultrasonography in determining severity of renal artery stenosis

BACKGROUND: Renal artery stenosis is one of the important causes of hypertension and endstage renal failure. Magnetic resonance angiography (MRA) and Doppler ultrasonography arenon-invasive and safe diagnostic techniques that have also high sensitivity and specificity. Sincethe accuracy and reliability of these techniques depend upon technicians and softwares, wedecided to evaluate and compare the sensitivity and specificity of these techniques in Isfahan.METHODS: Our study included all the patients (۳۷ patients) who underwent renal arteryangiography during ۲ years from May ۲۰۰۳ to May ۲۰۰۵ and up to six months after that hadunderwent MRA (۲۱ patients) and Doppler sonography (۱۶ patients) in Isfahan. Renal arteryangiography was considered as the gold standard.RESULTS: Sensitivity, specificity, positive and negative predictive values of ۱۰۰%, ۲۵%, ۲۵%,and ۱۰۰% were obtained for MRA respectively. Specificity and positive predictive values (PPV)of Doppler sonography were ۶۷%. Its sensitivity and negative predictive values (NPV) were ۵۷%.CONCLUSION: Although it seems that technician dependency, technical and softwareproblems were the reasons of low specificity of gadolinium-enhanced MRA in our study, furtherstudies with larger sample sizes are recommended.Keywords: MRA, Doppler Ultrasonography, Renal Artery Stenosis.