Dynamic Changes of Asymmetric Cortical Veins Relate to Neurologic Prognosis in Acute Ischemic Stroke.

Abstract

Background Cerebral oxygenation is closely related to neural function in acute ischemic stroke (AIS) and can be measured noninvasively from asymmetrically prominent cortical veins (APCVs) using quantitative susceptibility mapping (QSM). Purpose To quantify venous oxygen saturation (SvO₂) using brain MRI with QSM in patients with AIS, to analyze its change at 2-week follow-up, and to assess the influence of SvO₂ in clinical prognosis. Materials and Methods Between 2016 and 2020, consecutive patients with AIS who underwent brain MRI within 24 hours from symptom onset and 2 weeks after treatment were retrospectively enrolled. The SvO₂ of APCVs was quantified using QSM. The independent sample <i>t</i> test was used to compare the SvO₂ between patients with and patients without APCVs. The paired sample <i>t</i> test was used to assess the dynamic change in SvO₂. Pearson and Spearman correlation analysis was used to explore the relationship among dynamic change in SvO₂ and hypoperfusion, National Institutes of Health Stroke Scale (NIHSS) score change, and 90-day modified Rankin Scale (mRS) score. The independent sample <i>t</i> test was used to compare the dynamic change in SvO₂ between different clinical prognoses and outcome subgroups. Results APCVs were detected in 39 of 73 patients (mean age, 70 years ± 10 [standard deviation]; 49 men) at admission and disappeared in 35 patients at 2-week follow-up MRI. The mean SvO₂ increased from 35.0% ± 5.8 to 64.5% ± 10.0 (<i>P</i> < .001) in 39 patients. For the 35 patients with APCVs that disappeared, the dynamic change in SvO₂ negatively correlated with change in NIHSS score (<i>r</i> = -0.37, <i>R</i>² = 0.19, <i>P</i> = .03) and 90-day mRS score (<i>r</i> = -0.54, <i>R</i>² = 0.27, <i>P</i> = .001), and the dynamic change in SvO₂ in the subgroup with good 90-day outcomes (<i>n</i> = 19) was greater than that in the subgroup with poor 90-day outcomes (<i>n</i> = 16) (mean, 34.5% ± 5.8 vs 29.7% ± 6.3; 95% CI: 0.6, 8.9; <i>P =</i> .03). Conclusion Improved oxygen saturation of asymmetric cortical veins detected using brain MRI with quantitative susceptibility mapping corresponded with better acute ischemic stroke outcomes for patients with asymmetrically prominent cortical veins that disappeared at 2-week follow-up MRI. © RSNA, 2021 <i>Online supplemental material is available for this article.</i>