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

<bold>Background: </bold>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.<bold>Purpose: </bold>To compare the aneurysm wall visualization on pre- and post-3D isotropic T1 -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.<bold>Study Type: </bold>Prospective.<bold>Population: </bold>Twenty-nine patients with a total of 35 unruptured intracranial aneurysms.<bold>Sequence: </bold>3D T1 -weighted pre- and postcontrast SPACE (0.5 mm isotropic) at 3.0T.<bold>Assessment: </bold>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.<bold>Statistical Test: </bold>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.<bold>Results: </bold>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).<bold>Data Conclusion: </bold>3D T1 -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.<bold>Level Of Evidence: </bold>2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:193-200. [ABSTRACT FROM AUTHOR]