T2 dark blood MRA for renal artery stenosis detection: preliminary observations.

OBJECTIVE: This study evaluated the ability of a fast spin echo T2 weighted dark blood sequence to characterize significant (>50%) renal artery stenosis compared to conventional angiography. METHODS: Sixteen patients underwent conventional catheter angiography for either renal artery stenosis evaluation or as potential renal donors. Each patient then had an MR study of the renal arteries and kidneys with fast spin echo T2 weighted MR (TR 4000, TE 102, 8 echo train length) on a Superconducting 1.5T Magnet. Results were compared with angiography and inter and intra observer statistics were calculated. RESULTS: A total of 36 renal arteries were imaged in 32 kidneys with 12 stenoses >50%. Fast spin echo T2 weighted MR is 94% accurate (95%CI: 87-100%) in detection of significant renal artery stenosis. Dark blood MRA (DBMRA) is 96% sensitive (95%CI: 89-100), 92% specific, with a predictive value positive of 96% for classifying real arteries as normal or significantly stenosed. Inter and intra observer statistics demonstrate good to excellent agreement in renal artery classification (kappa>0.60). CONCLUSION: DBMRA may be a useful adjunct to renal MR evaluation in hypertension. SUMMARY: A total of 36 renal arteries were imaged in 32 kidneys with 12 stenoses >50%. Fast spin echo T2 weighted MR is 94% accurate (95%CI: 87-100%) in detection of significant renal artery stenosis.