12 research outputs found
Comparing MRI metrics to quantify white matter microstructural damage in multiple sclerosis
Quantifying white matter damage in vivo is becoming increasingly important for investigating the effects of neuroprotective and repair strategies in multiple sclerosis (MS). While various approaches are available, the relationship between MRIâbased metrics of white matter microstructure in the disease, that is, to what extent the metrics provide complementary versus redundant information, remains largely unexplored. We obtained four microstructural metrics from 123 MS patients: fractional anisotropy (FA), radial diffusivity (RD), myelin water fraction (MWF), and magnetisation transfer ratio (MTR). Coregistration of maps of these four indices allowed quantification of microstructural damage through voxelâwise damage scores relative to healthy tissue, as assessed in a group of 27 controls. We considered three white matter tissueâstates, which were expected to vary in microstructural damage: normal appearing white matter (NAWM), T2âweighted hyperintense lesional tissue without T1âweighted hypointensity (T2L), and T1âweighted hypointense lesional tissue with corresponding T2âweighted hyperintensity (T1L). All MRI indices suggested significant damage in all three tissueâstates, the greatest damage being in T1L. The correlations between indices ranged from r = 0.18 to r = 0.87. MWF was most sensitive when differentiating T2L from NAWM, while MTR was most sensitive when differentiating T1L from NAWM and from T2L. Combining the four metrics into one, through a principal component analysis, did not yield a measure more sensitive to damage than any single measure. Our findings suggest that the metrics are (at least partially) correlated with each other, but sensitive to the different aspects of pathology. Leveraging these differences could be beneficial in clinical trials testing the effects of therapeutic interventions
Comprehensive Venous Outflow Predicts Functional Outcomes in Patients with Acute Ischemic Stroke Treated by Thrombectomy.
BACKGROUND AND PURPOSE: Cortical venous outflow has emerged as a robust measure of collateral blood flow in acute ischemic stroke. The addition of deep venous drainage to this assessment may provide valuable information to further guide the treatment of these patients.
MATERIALS AND METHODS: We performed a multicenter retrospective cohort study of patients with acute ischemic stroke treated by thrombectomy between January 2013 and January 2021. The internal cerebral veins were scored on a scale of 0-2. This metric was combined with existing cortical vein opacification scores to create a comprehensive venous outflow score from 0 to 8 and stratify patients as having favorable-versus-unfavorable comprehensive venous outflow. Outcome analyses were primarily conducted using the Mann-Whitney
RESULTS: Six hundred seventy-eight patients met the inclusion criteria. Three hundred fifteen were stratified as having favorable comprehensive venous outflow (mean age, 73âyears; range, 62-81 years; 170 men), and 363, as having unfavorable comprehensive venous outflow (mean age, 77âyears; range, 67-85 years; 154 men). There were significantly higher rates of functional independence (mRS 0-2; 194/296 versus 37/352, 66% versus 11%,
CONCLUSIONS: A favorable comprehensive venous profile is strongly associated with functional independence and excellent postthrombectomy reperfusion. Future studies should focus on patients with venous outflow status that is discrepant with the eventual outcome
Aspiration Versus StentâRetriever as FirstâLine Endovascular Therapy Technique for Primary Medium and Distal Intracranial Occlusions: A PropensityâScore Matched Multicenter Analysis
Background For acute proximal intracranial artery occlusions, contact aspiration may be more effective than stentâretriever for firstâline reperfusion therapy. Due to the lack of data regarding medium vessel occlusion thrombectomy, we evaluated outcomes according to firstâline technique in a large, multicenter registry. Methods Imaging, procedural, and clinical outcomes of patients with acute proximal medium vessel occlusions (M2, A1, or P1) or distal medium vessel occlusions (M3, A2, P2, or further) treated at 37 sites in 10 countries were analyzed according to firstâline endovascular technique (stentâretriever versus aspiration). Multivariable logistic regression and propensityâscore matching were used to estimate the odds of the primary outcome, expanded Thrombolysis in Cerebral Infarction score of 2bâ3 (âsuccessful recanalizationâ), as well as secondary outcomes (firstâpass effect, expanded Thrombolysis in Cerebral Infarction 2câ3, intracerebral hemorrhage, and 90âday modified Rankin scale, 90âday mortality) between treatment groups. Results Of the 440 included patients (44.5% stentâretriever versus 55.5% aspiration), those treated with stentâretriever had lower baseline Alberta Stroke Program Early Computed Tomography Scale scores (median 8 versus 9; P<0.01), higher National Institutes of Health Stroke Scale scores (median 13 versus 11; P=0.02), and nonsignificantly fewer mediumâdistal occlusions (M3, A2, P2, or other: 17.4% versus 23.8%; P=0.10). Use of a stentâretriever was associated with 15% lower odds of successful recanalization (odds ratio [OR], 0.85; [95% CI 0.74â0.98]; P=0.02), but this was not significant after multivariable adjustment in the total cohort (adjusted OR, 0.88; [95% CI 0.72â1.09]; P=0.24), or in the propensityâscore matched cohort (n=105 in each group) (adjusted OR, 0.94; [95% CI 0.75â1.18]; P=0.60). There was no significant association between technique and secondary outcomes in the propensityâscore matched adjusted models. Conclusion In this large, diverse, multinational medium vessel occlusion cohort, we found no significant difference in imaging or clinical outcomes with aspiration versus stentâretriever thrombectomy