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ObjectiveTo evaluate the role of blood pressure as mediator of the effect of conscious sedation (CS) compared to local anesthesia (LA) on functional outcome after EVT.MethodsPatients treated in MR CLEAN Registry centers with CS or LA as preferred anesthetic approach during EVT for ischemic stroke were analyzed. First, we evaluated the effect of CS on area under the threshold (AUT), relative difference between baseline and lowest procedural mean arterial pressure (∆LMAP) and procedural blood pressure trend, compared to LA. Second, we assessed the association between blood pressure and functional outcome (modified Rankin Scale, mRS) with multivariable regression. Lastly, we evaluated whether blood pressure explained the effect of CS on mRS.ResultsIn 440 patients with available blood pressure data, patients treated under CS (n = 262) had larger AUTs (median 228 vs 23 mm Hg*min), larger ∆LMAP (median 16% vs 6%) and a more negative blood pressure trend (−0.22 vs −0.08 mm Hg/min) compared to LA (n = 178). Larger ∆LMAP and AUTs were associated with worse mRS (adjusted common OR (acOR) per 10%-drop 0.87, 95%CI 0.78–0.97, and acOR per 300 mm Hg*min 0.89, 95%CI 0.82–0.97). Patients treated under CS had worse mRS compared to LA (acOR 0.59, 95%CI 0.40–0.87) and this association remained when adjusting for ∆LMAP and AUT (acOR 0.62, 95%CI0.42–0.92).ConclusionsLarge blood pressure drops are associated with worse functional outcome. However, blood pressure drops do not explain the worse outcomes in the CS group.

Background and purpose: A wide variation of MRI systems is a challenge in multicenter imaging biomarker studies as it adds variation in quantitative MRI values. The aim of this study was to design and test a quality assurance (QA) framework based on phantom measurements, for the quantitative MRI protocols of a multicenter imaging biomarker trial of locally advanced cervical cancer.Materials and methods: Fifteen institutes participated (five 1.5 T and ten 3 T scanners). Each institute optimized protocols for T2, diffusion-weighted imaging, T1, and dynamic contrast-enhanced (DCE-)MRI according to system possibilities, institutional preferences and study-specific constraints. Calibration phantoms with known values were used for validation. Benchmark protocols, similar on all systems, were used to investigate whether differences resulted from variations in institutional protocols or from system variations. Bias, repeatability (%RC), and reproducibility (%RDC) were determined. Ratios were used for T2 and T1 values.Results: The institutional protocols showed a range in bias of 0.88-0.98 for T2 (median %RC = 1%; % RDC = 12%), -0.007 to 0.029 x 10(-3) mm(2)/s for the apparent diffusion coefficient (median %RC = 3%; % RDC = 18%), and 0.39-1.29 for T1 (median %RC = 1%; %RDC = 33%). For DCE a nonlinear vendor-specific relation was observed between measured and true concentrations with magnitude data, whereas the relation was linear when phase data was used.Conclusion: We designed a QA framework for quantitative MRI protocols and demonstrated for a multi-center trial for cervical cancer that measurement of consistent T2 and apparent diffusion coefficient values is feasible despite protocol differences. For DCE-MRI and T1 mapping with the variable flip angle method, this was more challenging. (C) 2020 The Authors. Published by Elsevier B.V.