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Contrast-enhanced 3D FISP MR angiography of the aortic arch ostia: preliminary results.

PURPOSE
The goal of this work was to evaluate three-dimensional (3D) contrast-enhanced MR angiography (MRA) for the detection of ostial stenoses of the aortic arch.


METHOD
Sixteen patients with suspected carotid atherosclerotic disease prospectively underwent digital subtraction angiography of the aortic arch followed by contrast-enhanced MRA using a 3D fast imaging with steady-state precession (FISP) technique (TR = 5 ms, TE = 2 ms, flip angle = 30 degrees). Three neuroradiologists blindly measured stenoses on the catheter angiograms and MRA. Evaluation included the ostia of the innominate, left carotid, and left subclavian arteries. Any significant disagreement on catheter angiography was resolved by consensus. The MRA grades of each of the three observers were then compared with the consensus grades of the contrast angiogram.


RESULTS
Forty-eight vessels were scored, of which five had significant stenoses. MRA demonstrated 100% sensitivity, 89% specificity, 52% positive predictive value, and 100% negative predictive value. The Bowker test for symmetry indicated no significant difference between conventional angiography and MRA scores (p = 0.32-0.75), and there was good agreement between the three observers (weighted kappa = 0.75-0.86).


CONCLUSION
Contrast-enhanced 3D FISP MRA may be a useful imaging modality for the detection of significant stenoses at the ostia of the major aortic arch branches.