Imaging diagnosis of renal artery stenosis:comparing CTA with 3D Time-of-Flight MR angiography

Objective To evaluate the diagnostic accuracy of CT renal artery angiography(CTA)and 3D Time-of-Flight MR angiography(3D TOF MRA)for the diagonosis of renal artery stenosis.Methods CTA and 3D TOF MRA were performed in 220 patients who were clinically diagnosed as secondary hypertension.The imaging diagnosis was compared with the clinical diagnosis,including the results of DSA.The imaging quality of the two methods were evaluated.Results Eighty-one cases were clinically diagnosed as renal artery stenosis.The diagnosis based on CT showed a sensitivity of 100%,a specificity of 98.5%,a positive predictive value of 93.1% and a negative predictive value of 100%,while the diagnosis based on 3D TOF MRA showed a sensitivity of 75.3%,a specificity of 100%,a positive predictive value of 100% and a negative predictive value of 95.2%.And the imaging quality of CTA was better than that of 3D TOF MRA.The sub-segment renal artery imaging of 3D TOF MRA could not be evaluated,especially those under 4th.Conclusion 3D TOF MR angiography is not reproducible or sensitive enough comparing to that of renal artery CT angiography.