Carrión‐Penagos, Julián

Background Transcranial Doppler (TCD) is a non-invasive, bedside tool that allows for real-time monitoring of the patient’s hemodynamic status following mechanical thrombectomy (MT). This systematic review and meta-analysis aims to evaluate the predictive value of TCD parameters following successful MT (Thrombolysis in Cerebral Infarction 2b–3). Methods In July 2024, we searched PubMed, Embase, and Scopus, to identify observational studies in which TCD parameters were measured within 48 hours of MT. Using random-effects models, we compared four TCD parameters (mean flow velocity (MFV), MFV index, pulsatility index (PI), and peak systolic velocity (PSV) among groups with vs without hemorrhagic transformation (HT) and favorable vs poor functional recovery (modified Rankin Scale 0–2 vs 3–6). Results Eleven studies comprising 1432 patients (59% male; mean age range: 63–73 years) were included. The MFV and MFV index were higher in patients with HT (Hedges' g=0.42 and 0.54, P=0.015 and 0.005, respectively). Patients with MFV index ≥1.3 showed a higher risk of all HT (RR 1.97; 95% confidence interval (CI) 1.28 to 3.03, P=0.002), symptomatic HT (RR 4.68; 95% CI 1.49 to 14.65, P=0.008), and poor functional status at 90 days (RR 1.65; 95% CI 1.27 to 2.14, P=0.029), respectively. There was no difference in mean PSV (P=0.1) and PI (P=0.3) among groups with and without HT. Conclusion This study underscores the prognostic value of the MFV index in predicting HT, symptomatic HT, and poor functional recovery after successful MT in the anterior circulation. Large-scale, multi-center studies are necessary to confirm these findings and to validate the MFV index as a reliable predictor for improving post-thrombectomy care.

Background and Purpose: Brain cavernous angiomas with symptomatic hemorrhage (CASH) have a high risk of neurological disability from recurrent bleeding. Systematic assessment of baseline features and multisite validation of novel magnetic resonance imaging biomarkers are needed to optimize clinical trial design aimed at novel pharmacotherapies in CASH. Methods: This prospective, multicenter, observational cohort study included adults with unresected, adjudicated brain CASH within the prior year. Six US sites screened and enrolled patients starting August 2018. Baseline demographics, clinical and imaging features, functional status (modified Rankin Scale and National Institutes of Health Stroke Scale), and patient quality of life outcomes (Patient-Reported Outcomes Measurement Information System-29 and EuroQol-5D) were summarized using descriptive statistics. Patient-Reported Outcomes Measurement Information System-29 scores were standardized against a reference population (mean 50, SD 10), and one-sample t test was performed for each domain. A subgroup underwent harmonized magnetic resonance imaging assessment of lesional iron content with quantitative susceptibility mapping and vascular permeability with dynamic contrast-enhanced quantitative perfusion. Results: As of May 2020, 849 patients were screened and 110 CASH cases enrolled (13% prevalence of trial eligible cases). The average age at consent was 46±16 years, 53% were female, 41% were familial, and 43% were brainstem lesions. At enrollment, ≥90% of the cohort had independent functional outcome (modified Rankin Scale score ≤2 and National Institutes of Health Stroke Scale score <5). However, perceived health problems affecting quality of life were reported in >30% of patients (EuroQol-5D). Patients had significantly worse Patient-Reported Outcomes Measurement Information System-29 scores for anxiety ( P =0.007), but better depression ( P =0.002) and social satisfaction scores ( P =0.012) compared with the general reference population. Mean baseline quantitative susceptibility mapping and permeability of CASH lesion were 0.45±0.17 ppm and 0.39±0.31 mL/100 g per minute, respectively, which were similar to historical CASH cases and consistent across sites. Conclusions: These baseline features will aid investigators in patient stratification and determining the most appropriate outcome measures for clinical trials of emerging pharmacotherapies in CASH.

BackgroundQuantitative susceptibility mapping (QSM) and dynamic contrast‐enhanced quantitative permeability (DCEQP) on magnetic resonance (MR) have been shown to correlate with neurovascular disease progression as markers of vascular leakage and hemosiderin deposition. Applying these techniques as monitoring biomarkers in clinical trials will be necessary; however, their validation across multiple MR platforms and institutions has not been rigorously verified.PurposeTo validate quantitative measurement of MR biomarkers on multiple instruments at different institutions.Study TypePhantom validation between platforms and institutions.Phantom ModelT1/susceptibility phantom, two‐compartment dynamic flow phantom.Field Strength/Sequence3T/QSM, T1 mapping, dynamic 2D SPGR.AssessmentPhilips Ingenia, Siemens Prisma, and Siemens Skyra at three different institutions were assessed. A QSM phantom with concentrations of gadolinium, corresponding to magnetic susceptibilities of 0, 0.1, 0.2, 0.4, and 0.8 ppm was assayed. DCEQP was assessed by measuring a MultiHance bolus as the consistency of the width ratio of the curves at the input and outputs over a range of flow ratios between outputs.Statistical TestsEach biomarker was assessed by measures of accuracy (Pearson correlation), precision (paired t‐test between repeated measurements), and reproducibility (analysis of covariance [ANCOVA] between instruments).ResultsQSM accuracy of r2 > 0.997 on all three platforms was measured. Precision (P = 0.66 Achieva, P = 0.76 Prisma, P = 0.69 Skyra) and reproducibility (P = 0.89) were good. T1 mapping of accuracy was r2 > 0.98. No significant difference between width ratio regression slopes at site 2 (P = 0.669) or site 3 (P = 0.305), and no significant difference between width ratio regression slopes between sites was detected by ANCOVA (P = 0.48).Data ConclusionThe phantom performed as expected and determined that MR measures of QSM and DCEQP are accurate and consistent across repeated measurements and between platforms.Level of Evidence: 1Technical Efficacy Stage: 2J. Magn. Reson. Imaging 2020;51:1192–1199.