Assessment of cerebrovascular hemodynamic status in ischemic cerebrovascular disease multimodal magnetic resonance imaging (MRI): A diagnostic study

Objective This study aimed to evaluate the clinical utility of a multimodal Magnetic Resonance Imaging (MRI) protocol in the noninvasive characterization of cerebrovascular hemodynamic alterations in patients with ischemic cerebrovascular disease. Methods A cohort of 82 subjects diagnosed with ischemic cerebrovascular disease was prospectively enrolled and further stratified into two groups: cerebral infarction (CI) group (n = 48) and transient ischemic attack (TIA) group (n = 34). Every participant underwent neuroimaging examination, including conventional cranial MRI acquisitions, echo-planar diffusion-weighted imaging sequences, fluid-attenuated inversion recovery (FLAIR) pulse sequences, three-dimensional time-of-flight (3D-TOF) magnetic resonance angiography (MRA), and susceptibility-weighted imaging (SWI). The modified Thrombolysis in Cerebral Infarction (mTICI) grading system was used to perform semiquantitative grading of distal arterial visualization in the symptomatic arterial territory. Favorable distal arterial visualization was defined using the prespecified MRA grading threshold, while prominent cortical veins (PCV) on SWI were recorded as a marker associated with increased oxygen extraction in the symptomatic territory. Concurrently, the extent of pial arterial collateral recruitment and the robustness of secondary hemodynamic support pathways were quantified utilizing the regional leptomeningeal collateral (rLMC) scoring system. Additionally, patients were stratified by time from symptom onset into ≤7-day and >7-day subgroups for further analysis. Results Compared with the TIA group, the proportion of patients with good distal arterial visualization (mTICI ≥ 2b) was significantly lower in the CI group (60.42% vs 79.41%; unadjusted odds ratio (OR) = 0.40, 95% confidence interval (95% CI) 0.17–0.94; P = 0.027), the mean rLMC score was also lower (10.71 ± 2.30 vs 13.41 ± 2.86; mean difference = −2.70, 95% CI −3.95 to −1.45; P < 0.001). The PCV positivity rate (70.83% vs 35.29%; unadjusted OR = 4.44, 95% CI 1.72–11.45; P = 0.002) and the detection rate of cerebral microbleeds (43.75% vs 20.59%; unadjusted OR = 3.00, 95% CI 1.15–7.83; P = 0.025) were both higher in the CI group than in the TIA group. After adjustment, the associations of disease category with good distal arterial visualization, rLMC score, and PCV positivity remained significant, whereas the association with cerebral microbleed detection was no longer significant. In the time-from-onset subgroup analysis, in the CI group, the>7-day subgroup exhibited a significantly lower proportion of good distal arterial visualization, lower rLMC scores, and a higher PCV positivity rate, compared with the ≤7-day subgroup (all P < 0.05). Conversely, in the TIA group, the>7-day subgroup showed significantly higher proportions of good distal arterial visualization and higher rLMC scores, as well as a lower PCV positivity rate, relative to the ≤7-day subgroup (all P < 0.05). When the patients were stratified according to different time-from-onset intervals, the detection rates of microbleeds did not differ significantly between the various subgroups within either the CI group or the TIA group ( P > 0.05). Conclusion Combined MRA and SWI provide complementary noninvasive information on arterial, collateral, venous, and microvascular imaging features in ischemic cerebrovascular disease. The CI group and the TIA group differed with respect to these imaging markers, whereas cerebral microbleeds remained relatively stable across subgroups stratified by the time from symptom onset to imaging.