Visualizing wall enhancement over time in unruptured intracranial aneurysms using 3D vessel wall imaging

Background Few studies directed at assessing the visualization of the walls of unruptured aneurysms have used higher-resolution 3D MRI vessel wall imaging. Prospective longitudinal studies are also needed to screen vessel wall changes in unruptured aneurysms. Purpose To compare the aneurysm wall visualization on pre- and post-3D isotropic T-1-weighted Sampling Perfection with Application-optimized Contrasts by using different flip angle Evolutions (SPACE) images and to explore whether there is a change in wall enhancement at follow up. Study Type Prospective. Population Twenty-nine patients with a total of 35 unruptured intracranial aneurysms. Sequence 3D T-1-weighted pre- and postcontrast SPACE (0.5 mm isotropic) at 3.0T. Assessment The aneurysm wall visibility (0-5 scale) between pre- and postcontrast images as well as the wall enhancement (0-5 scale) between follow-up and baseline studies (6-30 months, average 12.7 months) were compared. Differences in wall visibility and enhancement were also investigated as a function of aneurysm diameter and location. Statistical Test The Wilcoxon signed rank paired test was used to compare the wall visibility score between pre- and postcontrast SPACE images, as well as wall enhancement between follow-up and baseline. The Mann-Whitney and Kruskal-Wallis tests were used to investigate the enhancement difference between different diameters and locations. Results Postcontrast images had significantly higher wall visibility (P = 0.01). A wall enhancement score >= 2 was found in 71% of the aneurysms. Changes in levels of wall enhancement were found in 17% of the aneurysms at follow-up studies, but those changes were small. Wall visibility and enhancement scores of large aneurysms were significantly higher than small ones (P < 0.001). Data Conclusion 3D T-1-weighted higher resolution SPACE can be used to assess changes in enhancement at follow-up studies. Contrast SPACE image provides better aneurysm wall visibility and improves visualization of the aneurysm wall. Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:193-200.