Dark-blood MRI of the thoracic aorta with 3D diffusion-prepared steady-state free precession: initial clinical evaluation.

Abstract

The purpose of this study was to compare the performance of 3D diffusion-prepared balanced steady-state free precession (SSFP) imaging with that of 3D contrast-enhanced MR angiography in evaluation of the thoracic aorta. Twenty-one patients with indications for contrast-enhanced MR angiography and diffusion-prepared SSFP of the thoracic aorta were involved in this retrospective chart review study conducted with 1.5-T MRI. Two observers scored the quality of the contrast-enhanced MR angiographic and diffusion-prepared SSFP images on the basis of depicting the thoracic aorta. Image quality scores and diametric measurements of the aorta from both image sets were compared. Diametric measurements of the thoracic aorta showed a strong linear association (r = 0.971, p < 0.0001; regression line indifferent from line of equality, p < 0.05). The aortic root was better visualized with contrast-enhanced MR angiography (image quality score, 3.6 +/- 0.9 vs 3.0 +/- 0.8 of 5; p < 0.05); however, the aortic wall was better visualized with diffusion-prepared SSFP (image quality score, 4.4 +/- 0.6 vs 1.9 +/- 0.3 of 5; p < 0.0001). Three-dimensional diffusion-prepared SSFP yields better image quality than 3D contrast-enhanced MR angiography in evaluation of the thoracic aortic wall and appears to be a useful adjunct to 3D contrast-enhanced MR angiography for assessing aortic abnormalities before administration of a contrast agent.