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Objectives: Cerebral hemodynamic impairment in patients with asymptomatic high-grade internal carotid artery (ICA) stenosis confers a risk of stroke and cognitive decline, but correlations between degree of stenosis and hemodynamic impairment are derived from small case series only. Using baseline data from 282 participants in the Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis – Hemodynamics (CREST-H) study, we hypothesized that degree of stenosis, measured by peak systolic velocity (PSV) and end diastolic velocity (EDV) in the ipsilateral ICA, would correlate with time-to-peak (TTP) delay using MR (n=275) or CT (n=7) perfusion scans, adjusting for demographic and cardiovascular risk variables. Methods: Using a 7-10MHz Doppler probe, ICA PSV and EDV were assessed. Doppler results were adjudicated centrally. Dynamic contrast perfusion imaging was standardized across 61 CREST-H sites, using sequential T2*-weighted time-sequence scanning (e.g. TR=1500, TE=25ms, flip angle=60deg, phase=128, slice thickness=5mm for GE 3T magnet). CTP was acquired with standard clinical protocols. TTP delay was calculated in the ipsilateral versus contralateral MCA/ACA territories using OLEA software. Linear regression used TTP delay as the outcome variable and PSV and EDV as predictor variables, adjusting for covariates.The 282 with complete data for all variables were included in the analysis. Results: Among 392 CREST-H participants, 63% were men, 7% Black, 3% Hispanic, 33% with less than college education. Tables 1a/b show the regression results for PSV and EDV as main predictor variables. PSV and EDV on the index side significantly correlated with TTP delay (p=0.004, p=0.002 respectively). Neither PSV nor EDV on the non-index side correlated with TTP delay (p=0.49, p=0.82). Compared with moderate exercise, vigorous exercise correlated with lower TTP delay in both models (p=0.05. p=0.04). Compared with college graduates, those with HS education had longer TTP delays in both models (p=0.03. p=0.02). Conclusions: In this large cohort of patients with high-grade asymptomatic carotid stenosis, higher flow velocities correlated with greater TTP delays, suggesting an increasing hemodynamic impairment with greater degree of stenosis above 70%. Our findings have implications for management of asymptomatic carotid stenosis which are being tested in the CREST-H and CREST-2 studies. Exercise and education may independently impact cerebral hemodynamics.

BACKGROUND: Cerebral hemodynamic impairment in patients with asymptomatic high-grade (>70%) internal carotid artery (ICA) stenosis is associated with risk of stroke and cognitive decline, but correlations between the degree of stenosis and hemodynamic impairment are derived from small case series. Using baseline data from 242 participants in the CREST-H study (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis–Hemodynamics), we hypothesized that the degree of stenosis in the ICA would correlate with time-to-peak (TTP) delay in ipsilateral cerebral blood flow using MR/CT perfusion scans, adjusting for demographic and cardiovascular risk variables. METHODS: From all participants, ICAs were insonated using a 7 to 10 MHz probe for peak systolic velocity (PSV) and end diastolic velocity. Dynamic contrast perfusion imaging was standardized across 61 CREST-H sites, using standard sequential T2*-weighted perfusion imaging. CT perfusion used standard clinical protocols. TTP delay was calculated in the ipsilateral versus contralateral hemispheres. In cross-sectional analysis, linear regression was used to model TTP delay as the outcome variable and PSV, end diastolic velocity, and PSV ICA/common carotid artery ratio on the index and nonindex side as primary predictor variables in 6 separate models, adjusting for covariates, followed by automated backward elimination model reduction. RESULTS: Among 392 CREST-H participants, the 242 with complete data for all variables were included in the regression analysis (age, 70±7.6; 62% M). End diastolic velocity on the index side correlated with TTP delay (β=0.003, P =0.005). PSV had a similar correlation but did not reach significance (β=0.001, P =0.099), nor did ICA/common carotid artery ratio (β=0.003, P =0.126). Nonindex side PSV, end diastolic velocity, and ICA/common carotid artery ratio showed no correlation with TTP delay ( P =0.268, P =0.495, P =0.380, respectively). Circle of Willis completeness did not correlate with TTP. CONCLUSIONS: In this large cohort of patients with high-grade asymptomatic carotid stenosis, higher end-diastolic flow velocities correlated with greater TTP delays, supporting a definition of hemodynamically significant stenosis. Our findings have implications for the management of asymptomatic carotid stenosis, which will be tested in the CREST-H study. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03121209.

Background: Accurate characterization of tumor stiffness and adhesion is crucial when surgically resecting meningiomas. Currently, such determinations are difficult to ascertain through standard preoperative imaging diagnostics and clinical experience. Herein, we explored magnetic resonance elastography (MRE) as a means of assessing these parameters and thereby improving neurosurgical resections. Methods: This prospective study of 193 patients with meningiomas involved three distinct patient subsets (cohort 1, 88 [2017–2021]; cohort 2, 55 [2022–2023]; cohort 3, 50 [2023–2024]. We analyzed preoperatively obtained MRE data on meningioma stiffness (cohorts 1 and 2) and adhesion (cohort 2) for accuracy, while matching subjects with or without MRE studies (cohort 3, 1:1 ratio) to define the role of preoperative MRE in improving operative outcomes. Results: Areas under the curve (AUCs) for MRE in gauging meningioma stiffness and adhesion were 0.87 and 0.89, respectively. Both parameters significantly surpassed empiric predictions of stiffness and adhesion rendered by surgeons and radiologists, based on routine magnetic resonance imaging (MRI). MRE-determined stiffness measures independently correlated with prolonged resection duration, whereas MRE-assessed adhesion showed independent associations with increased blood loss, longer duration of tumor resection, and higher risk of pial injury. Ultimately, results based on cohort 3 demonstrated that MRE has great potential in this setting to improve neurosurgical procedures by significantly reducing intraoperative bleeding, resection duration, and risks of pial injury. Conclusion: MRE is a promising, noninvasive tool for accurately assessing meningioma stiffness and adhesion, standing to improve the precision and safety of needed surgical intervention.

Background: Meniscal preservation has been demonstrated to contribute to long-term knee health and has been a successful intervention in isolation and in patients with anterior cruciate ligament reconstruction (ACLR). The long-term results of meniscal repair in the setting of revision ACLR have yet to be documented. Purpose: To report the incidence of meniscal repair failures at the 6-year follow-up in a cohort of patients who underwent concurrent revision ACLR and primary meniscal repair. Study Design: Prospective cohort study; Level of evidence, 2. Methods: All revision ACLRs with concomitant primary meniscal repair cases from a multicenter group between 2006 and 2011 were selected. Six-year follow-up was obtained to determine whether any subsequent surgery had occurred since their initial revision ACLR. If so, operative reports were obtained, whenever possible, to verify pathological condition and treatment. Results: In total, 221 patients from 1234 revision ACLRs underwent concurrent primary meniscal repairs (18% of the cohort). There were 238 repairs performed: 173 medial and 65 lateral. The majority of these repairs (n = 181; 76%) were performed with an all-inside technique. Six-year surgical follow-up was obtained in 77% (171/221) of the cohort, or 189 of 238 (79%) of the repairs (136 medial, 53 lateral). The meniscal repair failure rate, defined as reoperation, was 16% (31/189) at 6 years. Of the 31 failures, 28 were medial (24 all-inside, 4 inside-out; 28/136 = 20.6% failure rate) and 3 were lateral (2 all-inside, 1 inside-out; 3/53 = 5.7% failure rate). Three medial failures were treated in conjunction with a subsequent repeat revision ACLR. Medial tears underwent reoperation for failure at a significantly higher rate than lateral tears (20.6% vs 5.7%; P = .01) and had a significantly shorter survival time compared with lateral tears ( P = .02). No difference was found between the failure and nonfailure groups when it came to tear type, tear length, repair technique utilized, suture/implant type, or number of sutures used between the 2 groups. Conclusion: Meniscal repair in the revision ACLR setting has a 16% failure rate at 6 years. Failure rates for medial tears (20.6%) were found to be higher than that for lateral tears (5.7%), which aligns with previous studies in both the revision and primary ACLR setting.

ABSTRACT Background Magnetic resonance elastography (MRE) has demonstrated potential in characterizing intracranial tumors, including glioblastoma. The influence of pathology on measurement consistency and interobserver agreement needs evaluation to promote MRE implementation as a quantitative biomarker. Purpose To assess repeatability and interobserver agreement of absolute and normalized magnitude of the complex shear modulus (| G *|), storage modulus ( G ′), and loss modulus ( G ″) in glioblastoma. Study Type Prospective. Population Thirteen adults (5 male, 8 female, mean age 66.23 years) with histopathologically confirmed glioblastoma. Field Strength/Sequence 3 T MRI, modified single‐shot spin‐echo echo‐planar imaging. Assessment Two same‐session MRE acquisitions were performed with patient repositioning. The solid tumor component was independently segmented by 2 observers on contrast‐enhanced T1‐weighted images co‐registered to MRE maps. Statistical Tests Repeatability was assessed using the repeatability coefficient, coefficient of variation, and Bland–Altman plots, and interobserver agreement by the intraclass correlation coefficient. The Wilcoxon signed‐rank test compared parameters and coefficients of variation between tumor‐normal‐appearing white matter and absolute and normalized measurements. Significance was set at 0.05. Results Tumor | G *| and G ′ showed repeatability coefficients of 0.07–0.08 kPa and 0.05 kPa, compared with 0.13 kPa (| G *|) and 0.15–0.16 kPa ( G ′) for normalized measurements. Coefficients of variation in tumor regions were 1.42% ± 1.12%–1.60% ± 1.41% for | G *| and 1.19% ± 0.96%–2.08% ± 2.22% for G ′, significantly lower than normalized values (4.82% ± 4.49%–4.21% ± 4.27% for | G *|; 5.12% ± 5.04%–5.45% ± 4.53% for G ′). Tumor | G *| and G ′ showed excellent interobserver agreement (intraclass correlation coefficients 0.97 and 0.95). Tumor G ″ demonstrated higher variability than | G *| and G ′ (coefficients of variation 8.58% ± 7.69%–7.51% ± 6.73%), with no significant difference between absolute and normalized measurements ( p = 0.14). Data Conclusion Tumor | G *| and G ′ are the most repeatable metrics in glioblastoma. Normalization reduces measurement repeatability due to normal‐appearing white matter variability. The small sample size ( n = 13) limits generalizability. Evidence Level 2. Technical Efficacy Stage 2.

ImportanceStudies suggest that everolimus may reduce the risk of rejection, cardiac allograft vasculopathy (CAV), chronic kidney disease (CKD), and cytomegalovirus (CMV) after heart transplant. Everolimus use is controversial because of data demonstrating higher infection deaths when everolimus is introduced de novo after transplant. It is unclear whether everolimus is safe and effective when initiated at 6 months posttransplant in children, a population in which median graft survival is limited to 15 years and randomized clinical trials are lacking.ObjectiveTo evaluate the safety and efficacy of everolimus combined with low-dose tacrolimus to prevent major adverse transplant events (MATEs) in children after heart transplant.Design, Setting, and ParticipantsMulticenter, randomized, open-label, clinical trial enrolling 211 patients who were alive 6 months after pediatric heart transplant at 25 US sites from February 2018 to August 2020. The last date of follow-up was April 17, 2023.InterventionsParticipants were randomized to receive everolimus and low-dose tacrolimus (n = 107) or standard-dose tacrolimus and mycophenolate mofetil (n = 104) for 30 months.Main Outcomes and MeasuresThe primary efficacy end point was the MATE-3 score at 30 months, a validated composite ordinal end point including acute cellular rejection, CAV, and CKD. The primary safety end point was the MATE-6 score, encompassing the MATE-3 score plus antibody-mediated rejection, infection, and posttransplant lymphoproliferative disorder.ResultsAmong 211 children randomized, the mean age was 8.2 (SD, 6.3) years, 97 (46%) underwent transplant for congenital heart disease, and 49 (23%) were treated for rejection before 6 months. At 30 months, the mean MATE-3 score did not differ between the 2 treatment groups (mean difference, −0.32; 95% CI, −0.90 to 0.20; P = .16). The mean MATE-6 score was no higher in the everolimus group than in the mycophenolate group (baseline-adjusted mean difference, −0.40; 95% CI, −1.81 to 0.93), meeting the success criterion for safety (noninferiority margin <3). There were no differences in graft survival, MATE-free survival, or freedom from any individual MATE. Everolimus was associated with greater improvement in estimated glomerular filtration rate at 12 months (mean difference, 10.5 mL/min/1.73 m2; 95% CI, 1.09-19.91 mL/min/1.73 m2) and a lower incidence of CMV infection (hazard ratio, 0.50; 95% CI, 0.26-0.93).Conclusions and RelevanceAmong 6-month pediatric heart transplant survivors, everolimus and low-dose tacrolimus did not differ from tacrolimus and mycophenolate in preventing the composite of cellular rejection, CAV, and CKD at 30 months. However, everolimus and low-dose tacrolimus appear to be safe based on the total burden of 6 MATEs and may be associated with improved kidney function and less CMV infection.Trial RegistrationClinicalTrials.gov Identifier: NCT03386539

Abstract Background Flow‐related ghost artifact from a 3D Magnetization Prepared Rapid Gradient Echo (MPRAGE) sequence results from unsaturated magnetization of incoming arterial flow. This is especially common on MR scanners equipped with smaller radiofrequency (RF) transmit coils. A high‐performance compact 3T (C3T) scanner features a smaller RF‐transmit coil (inner diameter 37 cm, length 40 cm), leading to a rapid fall‐off of the B1 field below the neck. This configuration results in more intense flow‐related ghost artifacts, especially in younger patients. Purpose The C3T scanner's smaller RF‐transmit coil provides RF field coverage over the brain region, causing bright in‐flow arterial signals and flow‐related artifacts in the conventional 3D‐MPRAGE scans. The purpose of this study is to suppress these artifacts by adding a RF saturation band (RFSB) pulses to the 3D‐MPRAGE sequence. Methods The RFSB was added to the 3D‐MPRAGE sequence as a preparation pulse option. To test the effectiveness, 37 subjects were scanned on the C3T under an IRB‐approved protocol using 3D‐MPRAGE with and without RFSB. Ten of those subjects underwent repeated scans with and without RFSB to evaluate test‐retest reliability. A consensus evaluation by two neuroradiologists was performed on all data to compare signal to noise ratio, image contrast, presence of artifacts, and diagnostic confidence. Quantitative analysis included calculating test‐retest differences by image subtraction and evaluating the variance in flow‐artifact‐induced image intensity between the scans with and without RFSB. Additionally, one subject was scanned on a whole‐body 3T scanner using a transmit/receive (T/R) head coil to demonstrate the method's applicability across different MRI platforms as a proof of concept. Results The Wilcoxon signed‐rank test of the neuroradiologist evaluations showed a significant reduction in artifacts and an improvement in diagnostic confidence in the posterior fossa region with and without RFSB ( p < 0.0001). Test–retest analysis showed that adding RFSB significantly reduced image intensity variability in the cerebellum, even among subjects without visible flow artifacts. The normalized difference decreased from 8.71% to 6.41% ( p = 0.0059), suggesting improved image reliability in regions prone to flow‐related artifacts. Additionally, similar findings were observed in scans on a whole‐body 3T with a T/R head coil, demonstrating the broader applicability of this method. Conclusion Incorporating RFSB into 3D‐MPRAGE scans effectively reduces flow‐related ghost artifact on the C3T scanner, improving image quality and diagnostic confidence. These findings suggest that the proposed method could be widely implemented across MRI systems utilizing a smaller RF‐transmit coil.

ABSTRACTBackgroundPercutaneous transluminal angioplasty and stenting (PTAS) in patients with carotid stenosis may have potential effects on brain parenchyma. However, current studies on parenchymal changes are scarce due to the need for advanced imaging modalities. Consequently, the alterations in brain parenchyma following PTAS remain an unsolved issue.PurposeTo investigate changes to the brain parenchyma using magnetic resonance elastography (MRE).Study TypeProspective.Population13 patients (6 women and 7 men; 39 MRI imaging sessions) with severe unilateral carotid stenosis patients indicated for PTAS were recruited between 2021 and 2024.Field Strength/SequenceNoncontrast MRI sequences including MRE (spin echo) were acquired using 3 T scanners.AssessmentAll patients underwent MRE before (preprocedural), within 24 h (early postprocedural) and 3 months after (delayed postprocedural) PTAS. Preprocedural and delayed postprocedural ultrasonographic peak systolic velocity (PSV) was recorded. MRE stiffness and damping ratio were evaluated via neural network inversion of the whole brain, in 14 gray matter (GM) and 12 white matter (WM) regions.Statistical TestsStiffness and damping ratio differences between each pair of MR sessions for each subject were identified by paired sample t tests. The correlations of stiffness and damping ratio with stenosis grade and ultrasonographic PSV dynamics were evaluated by Pearson correlation coefficients. The statistical significance was defined as p < 0.05.ResultsThe stiffness of lesion side insula, deep GM, and deep WM increased significantly from preprocedural to delayed postprocedural MRE. Increasing deep GM stiffness on the lesion side was positively correlated with the DSA stenosis grade significantly (r = 0.609). The lesion side insula stiffness increments were positively correlated with PSV decrements significantly (r = 0.664).Data ConclusionRegional brain stiffness increased 3 months after PTAS. Lesion side stiffness was positively correlated with stenosis grades in deep GM and PSV decrements in the insula.Evidence Level2.Technical EfficacyStage 2.