Combined Use of X-ray Angiography and Intraprocedural MRI Enables Tissue-based Decision Making Regarding Revascularization during Acute Ischemic Stroke Intervention.

Background For patients with acute ischemic stroke undergoing endovascular mechanical thrombectomy with x-ray angiography, the use of adjuncts to maintain vessel patency, such as stents or antiplatelet medications, can increase risk of periprocedural complications. Criteria for using these adjuncts are not well defined. Purpose To evaluate use of MRI to guide critical decision making by using a combined biplane x-ray neuroangiography 3.0-T MRI suite during acute ischemic stroke intervention. Materials and Methods This retrospective observational study evaluated consecutive patients undergoing endovascular intervention for acute ischemic stroke between July 2019 and May 2020 who underwent either angiography with MRI or angiography alone. Cerebral tissue viability was assessed by using MRI as the reference standard. For statistical analysis, Fisher exact test and Student t test were used to compare groups. Results Of 47 patients undergoing acute stroke intervention, 12 patients (median age, 69 years; interquartile range, 60-77 years; nine men) underwent x-ray angiography with MRI whereas the remaining 35 patients (median age, 80 years; interquartile range, 68-86 years; 22 men) underwent angiography alone. MRI results influenced clinical decision making in one of three ways: whether or not to perform initial or additional mechanical thrombectomy, whether or not to place an intracranial stent, and administration of antithrombotic or blood pressure medications. In this initial experience, decision making during endovascular acute stroke intervention in the combined angiography-MRI suite was better informed at MRI, such that therapy was guided in real time by the viability of the at-risk cerebral tissue. Conclusion Integrating intraprocedural 3.0-T MRI into acute ischemic stroke treatment was feasible and guided decisions of whether or not to continue thrombectomy, to place stents, or to administer antithrombotic medication or provide blood pressure medications. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Lev and Leslie-Mazwi in this issue.

Diagnosis of spinal dural arteriovenous fistula using 3D T2-weighted imaging.

PURPOSE: To evaluate spinal MRIs without and with 3D T2W imaging among patients without and with spinal dural arteriovenous fistula (SDAVF) confirmed by spinal digital subtraction angiography (DSA). METHODS: A retrospective case-control study was performed among patients without and with SDAVF who had both spinal MRIs and gold standard spinal DSA. Two neuroradiologists independently reviewed spinal MRIs that were performed with either sagittal T2W turbo spin echo (2D group) or sagittal 3D T2W sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) (3D group) and documented the presence or absence of SDAVF. Using spinal DSA diagnosis as a gold standard, the sensitivity, specificity, and interobserver agreement for the 2D-group and 3D-group MRI diagnosis were calculated. RESULTS: The 2D group consisted of 21 patients and the 3D group consisted of 16 patients. For both radiologists, the 2D group demonstrated a sensitivity of 100% and specificity of 100%. Interobserver agreement in the 2D group was perfect (k = 1.0). For both radiologists, the 3D group demonstrated sensitivity of 100.0% and specificity of 92.3%. Interobserver agreement in the 3D group was perfect (k = 1.0). While flow voids were considered more conspicuous, spinal cord signal abnormality was considered less conspicuous with 3D T2W SPACE compared with conventional 2D STIR sequence. CONCLUSION: 3D T2W SPACE should be used in conjunction with 2D T2W sequences to more accurately detect abnormal cord signal and determine when perimedullary flow voids are pathologically abnormal for the radiologic diagnosis of SDAVF.

Clinical outcomes after revascularization for pediatric moyamoya disease and syndrome: A single-center series.

Moyamoya is a progressive cerebrovascular arteriopathy that affects children of any age. The goal of this study was to determine imaging and clinical outcomes as well as complication rates in a pediatric cohort undergoing either a combined direct/indirect or indirect-only revascularization approach. Patients with moyamoya disease or syndrome ≤ 18 years of age at the time of initial surgery were identified, and clinical data were collected retrospectively. Over a 12-year period, 26 patients underwent revascularization procedures on 49 hemispheres with a median follow-up of 2.6 years from surgery. Median age at surgery was 7.3 years (range 1.4-18.0 years). Thirty-three hemispheres (67.3%) underwent combined revascularization with a direct bypass and encephalomyosynangiosis, and sixteen hemispheres (32.7%) underwent indirect-only revascularization. The rate of 30-day perioperative complication was 10.2%, and the rate of postoperative clinical stroke by end of follow-up was 10.2% by hemisphere. There was a 5.7% rate of intraoperative bypass failure requiring conversion to an indirect revascularization approach. On follow-up imaging, 96.9% of direct bypasses remained patent. On multivariate analysis, higher preoperative Pediatric Stroke Outcome Measure (PSOM) scores were associated with lower rates of good clinical outcome on follow-up (unit OR 0.03; p = 0.03). Patients with age < 5.4 years had lower rates of good clinical outcome on follow-up. In this North American cohort, both combined direct/indirect and indirect only revascularization techniques were feasible. However, younger children < 5.4 years of age have worse outcomes than older children, similar to east Asian cohorts.