[Aortic diameter measurements on MRI follow-up of coarctation].

OBJECTIVE: During aortic coarctation follow-up, accurate diameter measurements using MRI are required. The purpose of this study was to compare the reproducibility of aortic measurements on axial and sagittal views using black blood (Fast-Spin-Echo) and three-dimensional Gadolinium-enhanced MR angiography.

SUBJECTS AND METHODS: We studied 34 patients who underwent evaluation after surgical treatment in the first year of life. The aortic measurements were made at six thoracic levels. We calculated the mean difference between the two sequences, and used Bland and Altman method and the comparison to zero.

RESULTS: With black blood, either on axial or sagittal views, aortic measurements were in agreement. Between two sequences, we considered as acceptable a mean difference of 0,5 mm with limits of agreement of +/- 3 mm. Difficulties were found for proximal ascending aorta measurements on all sequences. Using MR angiography, the highest agreement at the site of repair was on sagittal view, while the highest agreement at other sites was on axial views.

CONCLUSION: Black blood sequence provides a better reproducibility for aortic measurements than native slices of MR angiography.