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Introduction1.5 Tesla (1.5T) remain a significant field strength for brain imaging worldwide. Recent computer simulations and clinical studies at 3T MRI have suggested that dynamic susceptibility contrast (DSC) MRI using a 30° flip angle ("low-FA") with model-based leakage correction and no gadolinium-based contrast agent (GBCA) preload provides equivalent relative cerebral blood volume (rCBV) measurements to the reference-standard acquisition using a single-dose GBCA preload with a 60° flip angle ("intermediate-FA") and model-based leakage correction. However, it remains unclear whether this holds true at 1.5T. The purpose of this study was to test this at 1.5T in human high-grade glioma (HGG) patients.MethodsThis was a single-institution cross-sectional study of patients who had undergone 1.5T MRI for HGG. DSC-MRI consisted of gradient-echo echo-planar imaging (GRE-EPI) with a low-FA without preload (30°/P-); this then subsequently served as a preload for the standard intermediate-FA acquisition (60°/P+). Both normalized (nrCBV) and standardized relative cerebral blood volumes (srCBV) were calculated using model-based leakage correction (C+) with IBNeuro™ software. Whole-enhancing lesion mean and median nrCBV and srCBV from the low- and intermediate-FA methods were compared using the Pearson's, Spearman's and intraclass correlation coefficients (ICC).ResultsTwenty-three HGG patients composing a total of 31 scans were analyzed. The Pearson and Spearman correlations and ICCs between the 30°/P-/C+ and 60°/P+/C+ acquisitions demonstrated high correlations for both mean and median nrCBV and srCBV.ConclusionOur study provides preliminary evidence that for HGG patients at 1.5T MRI, a low FA, no preload DSC-MRI acquisition can be an appealing alternative to the reference standard higher FA acquisition that utilizes a preload.

This systematic review analyzes contemporary literature on racial/ethnic, insurance, and socioeconomic disparities within cerebrovascular surgery in the United States to determine areas for improvement. We conducted an electronic database search of literature published between January 1990 and July 2020 using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for studies analyzing a racial/ethnic, insurance, or socioeconomic disparity within adult cerebrovascular surgery. Of 2873 articles screened for eligibility by title and abstract, 970 underwent full-text independent review by 3 authors. Twenty-seven additional articles were identified through references to generate a final list of 47 included studies for analysis. Forty-six were retrospective reviews and 1 was a prospective observational cohort study, thereby comprising Levels III and IV of evidence. Studies investigated carotid artery stenting (11/47, 23%), carotid endarterectomy (22/47, 46.8%), mechanical thrombectomy (8/47, 17%), and endovascular aneurysm coiling or surgical aneurysm clipping (20/47, 42.6%). Minority and underinsured patients were less likely to receive surgical treatment. Non-White patients were more likely to experience a postoperative complication, although this significance was lost in some studies using multivariate analyses to account for complication risk factors. White and privately insured patients generally experienced shorter length of hospital stay, had lower rates of in-hospital mortality, and underwent routine discharge. Twenty-five papers (53%) reported no disparities within at least one examined metric. This comprehensive contemporary systematic review demonstrates the existence of disparity gaps within the field of adult cerebrovascular surgery. It highlights the importance of continued investigation into sources of disparity and efforts to promote equity within the field. [ABSTRACT FROM AUTHOR]