Arjen Lindenholz

158 CHAPTER 7 Abstract Background and purpose: Vessel wall MR imaging is increasingly performed in the diagnostic work-up of patients with ischemic stroke. The aim of this study was to compare vessel wall enhancement after intra-arterial thrombosuction with that in patients not treated with thrombosuction. Materials and methods: From 2009 to 2017, forty-nine patients with an ischemic stroke underwent 7T MR imaging within 3 months after symptom onset as part of a prospective intracranial vessel wall MR imaging study. Fourteen of these patients underwent intra-arterial treatment (IAT) using thrombosuction (IAT-group). In the IAT-group, vessel walls were evaluated for major vessel wall changes. All patients underwent pre- and postcontrast vessel wall MR imaging to assess enhancing foci of the vessel wall using coregistered subtraction images. A Wilcoxon signed-rank test was performed to test for differences. Results: In the IAT-group 11 of 14 patients (79%) showed vessel wall enhancement compared with 17 of 35 without intra-arterial treatment (49%). In the IAT-group, more enhancing foci were detected on the ipsilateral side ( n = 18.5) compared with the contralateral side ( n = 3, p = 0.005). Enhancement was more often concentric on the ipsilateral side ( n = 8) compared with contralateral side ( n = 0, p = 0.01). No differences were found in the non-IAT group between the number and configuration of ipsilateral and contralateral enhancing foci. Conclusion: Patients treated with intra-arterial treatment by means of thrombosuction showed more (concentric) enhancing foci of the vessel wall ipsilateral compared with contralateral to the treated artery than the patients without intra-arterial treatment, suggesting reactive changes of the vessel wall. This should be taken into account when assessing vessel wall MR images in patients with stroke.