Usefulness of additional diffusion MRI acquisition prior to mechanical thrombectomy for acute large vessel occlusion in the early time period at a CT-based stroke center

Abstract

ObjectiveThis study aimed to investigate whether evaluating the infarction core using additionally acquired diffusion magnetic resonance imaging (MRI) could help improve the assessment of prognosis including complication rates and modify the strategy for mechanical thrombectomy in endovascular procedures at a computed tomography (CT)-based stroke center. MethodsSingle-center data from patients with acute large-vessel occlusion in the anterior circulation who underwent mechanical thrombectomy between May 2018 and January 2021 were analyzed. Diffusion MRI sequences were performed during the preparation period for mechanical thrombectomy after CT angiography. We set the infarction core reference volume on diffusion MRI to 60 cc and divided the patients into two groups: a small infarction core group (less than 60 cc) and a large infarction core group (more than 60 cc). The baseline characteristics, radiological and clinical outcomes of the patients were investigated and compared between the two groups. ResultsThe difference in numbers between the two groups was not significant in the Alberta Stroke Program Early Computed Tomography (ASPECT) score; however, the ASPECT score on diffusion MRI showed a remarkable difference between the two groups. The large infarction core volume group on diffusion MRI had a poor prognosis, with the modified Rankin score at 90 days showing a statistically significant difference (p = 0.011). Complications after the procedure, such as hemorrhagic transformation, that can occur after reperfusion, symptomatic intracerebral hemorrhage, decompressive craniectomy for increased intracranial pressure, and mortality, were significantly more frequent in the large infarction core volume group. ConclusionAt a CT-based stroke center, additionally acquired diffusion MRI without a time delay for reperfusion would improve the assessment of prognosis including complication rate, and could help neurointerventionists determine the extent of recanalization of occluded vessels during mechanical thrombectomy.