Using Multimodal Imaging to Correlate Link Between Intracranial Aneurysms and Acute Ischemic Stroke

Background: The coincidence of unruptured cerebral aneurysms in acute ischemic stroke (AIS) is well known; however evidence on causality remains unclear. In this paper we are aiming to highlight key imaging characteristics that can aid in establishing or excluding a causative relationship between the two entities. Methods: Eight symptomatic patients with ischemic stroke and presence of an aneurysm in the same vascular territory were retrospectively analyzed. The patients were evaluated with computed tomography (CT) or magnetic resonance imaging (MRI) and depending on initial imaging findings, patients received either digital subtraction angiography (DSA) and MRI or MRI alone, with or without vessel wall imaging (VWI). Eligible patients received mechanical thrombectomy (MT) and the rest were managed conservatively. Results: The analysis of the imaging findings led to a proposed framework for classification/characterization of aneurysm as a possible, probable or improbable cause of AIS. The main findings used to categorize the aneurysmatic lesions were aneurysm thrombosis, positive vessel wall imaging, location and presence of comorbidities. Depending on the category the aneurysm was classified in, a decision regarding conducting treatment or not was made. Conclusions: Detailed observation of traditional imaging along with advanced MRI sequences like VWI can potentially help stratify the probability of aneurysms being the source of thromboembolic events.