AJNR. American journal of neuroradiology最新文献

Background and purpose: Current evidence suggests that tentorial dural arteriovenous fistulas with endovascular treatment offer a high rate of occlusion and reduced procedural risks. Here we report the clinical and angiographic outcomes in patients with tentorial dural arteriovenous fistulas who underwent endovascular treatment as first-line treatment.

Materials and methods: A retrospective analysis was conducted on 83 patients with tentorial dural arteriovenous fistulas treated at our center from April 2009 to November 2023 using endovascular treatment. Patient demographics, clinical presentation, angiographic, treatment results, and follow-up outcomes were registered. Univariable and multivariable logistic regression were performed to identify onset of intracranial hemorrhage predictors, procedure-related complications predictors and predictors of poor functional outcome.

Results: Eighty-three patients underwent endovascular treatment as first-line treatment. Most patients (80.7%) were symptomatic and a total of 25 patients (30.1%) presented with intracranial hemorrhage. Presence of deep venous drainage and midline location was associated with a lower incidence of intracranial hemorrhage. Middle meningeal artery (57.8%, 48/83) and pial artery (15.7%, 13/83) were the most frequently used access routes for embolization. A total of 74 (89.1%) TDAVFs were completely occluded after the last EVT session immediately. Complications occurred in 11 patients (13.3%). Six-month angiographic follow-up was performed in 68 patients (81.8%), and 91.2% (62/68) tentorial dural arteriovenous fistulas were occluded. At clinical follow-up (100%, 83/83), good functional outcome (mRS 0-2) was documented in 74 (89.1%) patients. Logistic regression analysis identified baseline mRS 3-5 as the most significant independent predictor of poor functional outcome. Subgroup analysis showed no statistically significant differences in baseline characteristics, angiographic and clinical results between patients treated with targeted pial artery embolization and non-targeted pial artery embolization.

Conclusions: Endovascular treatment is a safe and effective primary modality for managing tentorial dural arteriovenous fistulas, achieving high rates of complete angiographic occlusion and favorable functional outcomes. Transarterial embolization, predominantly via middle meningeal artery, was the mainstay of treatment. In patients with pial arterial feeders, omitting aggressive embolization did not compromise efficacy or increase complications.

Abbreviations: DAVF = dural arteriovenous fistula; TDAVF = tentorial dural arteriovenous fistula; EVT = endovascular treatment; TAE = transarterial embolization; TVE = transvenous embolization; MMA = middle meningeal artery.

Background and purpose: Endovascular thrombectomy outcomes are impacted by changes in stroke systems of care. During the pandemic, SARS-CoV2 positive status had major implications on hospital arrival and treatment models of non-COVID related hospital admissions. Using the Florida Stroke Registry, we compared the rates of in-hospital death and discharge outcomes of patients treated with endovascular thrombectomy who tested positive for SARS-CoV2 infection during their hospitalization.

Materials and methods: Data from Get with the Guidelines-Stroke hospitals participating in the Florida Stroke Registry during the COVID pandemic from March 2020 to December 2022 were reviewed to identify endovascular thrombectomy patients with coding for SARS-CoV2 testing during their hospital stay. Associations between SARS-CoV2 status and favorable endovascular thrombectomy outcomes of mRS (0-2) at discharge, discharge to home or rehabilitation centre, symptomatic intracerebral hemorrhage, in-hospital mortality, and independent ambulation at discharge were examined using multivariate logistic regression modeling adjusting for demographics, vascular risk factors, and clinical characteristics. Temporal analyses were used to compare outcomes across the study period.

Results: A total of 8,184 patients underwent endovascular thrombectomy (median age 71.1 years, female 50%, mean NIHSS 14), of these, 180 (2.2%) were SARS-CoV2 positive. Compared to SARS-CoV2 negative endovascular thrombectomy patients, those who tested positive were younger, more frequently male, but with comparable stroke severity at presentation. In multivariable analysis, adjusting for baseline differences and confounding variables, there was a 33% lower likelihood of being discharged to home/inpatient rehab (OR=0.67, 95% CI=(0.49-0.93)), 65% higher odds of in-hospital death (OR=1.65, 95% CI=(1.06-2.58)), as well as a 85% less chance of having a high mRS (>2) at discharge (OR=0.15, 95% CI=(0.04-0.60)) for patients with positive SARS-CoV2 infection. However, a similar risk of symptomatic intracerebral hemorrhage was present compared to SARS-CoV2 negative patients (OR=0.97, 95% CI=(0.501.88)). Temporal analysis of SARS-CoV2 positive patients showed no significant differences.

Conclusions: In this large multicenter stroke registry, despite comparable clinical presentation and in-hospital treatment timelines, SARS-CoV2 positive status negatively impacted thrombectomy outcomes.

Abbreviations: AIS = acute ischemic stroke; LVO = large vessel occlusion; EVT = endovascular thrombectomy; FSR = Florida Stroke Registry; sICH = symptomatic intracerebral hemorrhage.

Background and purpose: Proximal protection devices, such as TransCarotid Artery Revascularization (TCAR, SilkRoad Medical, Sunnyvale), aim to yield better outcomes in carotid artery stenting (CAS) than distal protection devices by preventing plaque embolization to the brain. However, transfemoral catheters may not fully reverse flow from the external carotid artery (ECA) to the internal carotid artery (ICA). We assess a new balloon-sheath device, Femoral Flow Reversal Access for Carotid Artery Stenting (FFRACAS), for this purpose.

Materials and methods: The FFRACAS prototype (ID = 0.117"; L=80cm) was compared to TCAR (ID=0.104", L=30cm) and MoMa (Medtronic, Minneapolis; ID=0.083", L=90cm) in a pulsatile flow model with blood simulant at 800mL/min. MoMa was used according to labeled instructions, with both CCA and ECA balloon inflation, without CCA-femoral vein shunt placement, and in an off-label fashion with single balloon occlusion in the CCA and shunt. Flow rates of the ICA, ECA, and shunt, when applicable, were monitored during CAS stages: CCA flow arrest, shunt activation, and stent delivery. Experiments were conducted under two ECA inflow conditions (-10 and -20 mL/min). Statistical comparison of ICA flow rates was conducted using ANOVA and Tukey's post-hoc tests.

Results: MoMa's on-label use maintained retrograde ICA flow (-0.3 mL/min) throughout CAS. Upon shunt activation, TCAR and FFRACAS reversed ICA flow similarly under low ECA inflow (ICA=-5.10 mL/min vs. -4.83 mL/min; p=0.349), but neither achieved ICA flow reversal under high ECA inflow or during stent delivery. MoMa off-label use failed to reverse ICA flow.

Conclusions: FFRACAS presents a potential alternative to TCAR, achieving similar degrees of flow reversal from a transfemoral approach to that achieved with the transcarotid approach. The MoMa system reliably prevents anterograde flow in ICA during CAS.

Abbreviations: CAS = Carotid Artery Stenting; TCAR = Transcarotid Arterial Revascularization; CCA = Common Carotid Artery; ICA = Internal Carotid Artery; ECA = External Carotid Artery; VA = Vertebral Artery; FFRACAS = Femoral Flow Reversal Access for Carotid Artery Stenting; ID = Inner Diameter; OD = Outer Diameter.

Background and purpose: Early identification of malignant cerebral edema (MCE) in patients with acute ischemic stroke is crucial for timely interventions. We aimed to identify regions critically associated with MCE using the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) to evaluate the association between location-specific-net water uptake (NWU) and MCE.

Materials and methods: This multicentre, retrospective cohort study included patients with acute ischemic stroke following large anterior circulation occlusion. The ASPECTS was determined by RAPID ASPECTS software. ASPECTS-NWU and Region-NWU were calculated automatically by comparing the Hounsfield units values in the ischemic and contralateral regions. Critical ASPECTS MCE regions and Region-NWU were evaluated by multivariate logistic regression and the areas under the receiver operating characteristic curves (AUCs).

Results: The study included 513 patients. Multivariate analysis showed that the ASPECTS insula (OR=2.49; 95% CI, 1.44-4.31) and M5 (OR=1.59; 95% CI, 1.11-3.41) regions were significantly associated with MCE. After adjustment, only the insula (OR=2.34; 95% CI, 1.23-4.45) was independently associated with MCE. Univariable ROC analysis found AUCs for Insula-NWU (AUC, 0.70; 95% CI, 0.65- 0.76)and ASPECTS-NWU (AUC, 0.64; 95% CI, 0.58-0.70) .The Insula-NWU had better diagnostic power than ASPECTS-NWU (DeLong test; P=0.01). A multivariate regression model that combined the NIHSS, ASPECTS, insula involvement, and Insula-NWU had good discriminatory power (AUC=0.80; 95% CI, 0.74-0.86) and better diagnostic power than Insula-NWU (DeLong test; P<0.01).

Conclusions: Brief statement directed to the stated purpose or hypothesis; no references should be cited.The insula region is critical for MCE, and Insula-NWU has better prediction efficacy than ASPECTS-NWU. This method does not rely on advanced imaging, facilitating rapid assessment in emergencies.

Abbreviations: ASPECTS = the Alberta Stroke Program Early Computed Tomography Score; AUC= the areas under the receiver operating characteristic curve; CT=computed tomography; CTP=CT perfusion; HU = hounsfield unit; MCE = malignant cerebral edema; NCCT=non-contrast Computed Tomography; NWU = net water uptake; ROC = receiver operating characteristic curve.

Prolonged imaging times and motion sensitivity at 7T necessitate advancements in image acceleration techniques. This study evaluates a 7T deep-learning (DL)-based image reconstruction using a deep neural network trained on 7T data, applied to T2-weighted turbo spin echo imaging. Raw k-space data from 30 consecutive clinical 7T brain MRI patients was reconstructed using both DL and standard methods. Qualitative assessments included overall image quality, artifacts, sharpness, structural conspicuity, and noise level, while quantitative metrics evaluated contrast-to-noise ratio (CNR) and image noise. DL-based reconstruction consistently outperformed standard methods across all qualitative metrics (p<0.001), with a mean CNR increase of 50.8% [95% CI: 43.0-58.6%] and a mean noise reduction of 35.1% [95% CI: 32.7-37.6%]. These findings demonstrate that DL-based reconstruction at 7T significantly enhances image quality without introducing adverse effects, offering a promising tool for addressing the challenges of ultra-high-field MRI.ABBREVIATIONS: CNR = contrast-to-noise ratio; DL = deep learning; GRAPPA = GeneRalized Autocalibrating Partially Parallel Acquisitions; IQR = interquartile range; MNI = Montreal Neurological Institute; SD = standard deviation.

The magnetic fields of the MR environment present unique safety challenges. Medical implants and retained foreign bodies can prevent patients from undergoing MR imaging due to interactions between the magnetic fields of the MR environment and the implant or foreign body. These hazards can be addressed through careful MR safety screening and MR examination customization, often allowing these patients with implants to undergo management-altering MR imaging. However, mitigating these risks takes additional time, expertise, and effort. Effective in 2025, this additional work is formally acknowledged with a new series of CPT® codes to report the work of assessing and addressing safety concerns associated with implants and foreign bodies in the MR environment. This user guide provides guidance on how to report these codes so physician led MR safety teams can be appropriately reimbursed for the additional work performed in preparing patients with implants or foreign bodies for MR imaging.ABBREVIATIONS: ACR = American College of Radiology™; ASNR = American Society of Neuroradiology; CPT® = Common Procedural Terminology; QHP = Qualified Healthcare Professional; ARRT® = American Registry of Radiologic Technologists; ABMRS = American Board of Magnetic Resonance Safety; MRSO = Magnetic Resonance Safety Officer; MRMD = Magnetic Resonance Medical Director; MRSE = Magnetic Resonance Safety Expert.

Background and purpose: Timely reporting of CTA exams impacts management of acute vascular pathology such as large vessel occlusions, arterial dissection, and ruptured aneurysm as well as a variety of acute non-vascular pathologies. In this study, we examine potential modifiable factors impacting the timeliness of CTA reporting performed in stroke code activations.

Materials and methods: Observational study of stroke code CTA head and neck exams performed at a single health system (3 emergency departments, 1550 inpatient beds) over four years (1/1/2019-12/31/2023). Patient age, patient sex, care setting, time of year, shift type, trainee/attending radiologist characteristics, report factors, and number of CTAs performed within the preceding hour were considered potential factors impacting the turnaround time (TAT) of stroke code CTAs. Descriptive statistics, univariate regression, and multivariate regression were used to estimate the impact on reporting TAT.

Results: 8422 stroke code CTA exams were performed. Median TAT was 29 minutes (IQR 18-48). Median TAT by individual attending radiologists varied from 15 to 40 minutes (median of medians 29 minutes [IQR 26-34.5]). Univariate regression analyses found lower patient age, emergency department setting, time later in the academic year, non-business hours, specific individual radiologists/trainees, solo-reporting by attending radiologists, use of preliminary reports, and fewer stroke codes within the preceding hour to all be associated with shorter TATs (all p<0.05). Adjusting for patient, logistical, and radiologist-level factors in a multivariate regression model, the greatest impact on TAT was seen with variation in individual attending radiologists (adjusted coefficients -2.6 to +43.3 minutes) and trainees (-49.6 to +109.0 minutes); reporting CTAs without a trainee and release of preliminary reports prior to final sign were associated with faster TATs (-11.4 and -24.7 minutes, respectively). Each stroke CTA within the preceding hour was associated with only a 4.0-minute increase in TAT. Secondary analyses suggested that previewing of cases during active scanning and use of "structured" reports correlates with favorable impact on TAT among attending radiologists (both p<0.05).

Conclusions: Radiologist and trainee-level timeliness in stroke CTA reporting varies widely. Interventions aimed at improving workflow efficiency for both trainees and attending radiologists could improve timeliness of reporting.

Abbreviations: IQR, interquartile range; TAT, turnaround time; TFR, time to final report.

Background and purpose: Prior investigations have noted the presence of peritumoral hyperintense signal (a "halo") around vestibular schwannomas on postcontrast 3D T2 FLAIR images. This study evaluated this phenomenon in a cohort of patients undergoing stereotactic radiosurgery.

Materials and methods: A retrospective review was completed of consecutive patients with presumed vestibular schwannomas undergoing stereotactic radiosurgery. Tumor size, location, presence or absence of a peritumoral halo, and halo thickness were recorded. Images were reviewed for presence and size of peritumoral hyperintense signal on postcontrast 3D T2 FLAIR images before and after treatment.

Results: Twenty-six patients were included in this study, 14 of which were female (54.0%). Average age was 62±12 years. Prior to treatment, a post-contrast 3D T2 FLAIR hyperintense peritumoral halo was seen in 85% of patients, averaging 0.8±0.4 mm in thickness. There was a higher incidence of peritumoral halo in post treatment patients (96%) than pre-treatment patients (85%) (p=0.017) with a mean follow up period of 1.2 years (SD, 0.35) from 11/12/2019 to 9/5/2023. The average halo thickness was also larger in posttreatment patients (average=1.4±0.4 mm) compared to pre-treatment patients (0.8±0.4 mm) (p<0.001). Average tumoral size did not significantly change following treatment (p=0.10).

Conclusions: Vestibular schwannomas treated with stereotactic radiosurgery are more likely to have a peritumoral halo on post-contrast 3D T2 FLAIR images, with larger halo size as compared to pre-treatment studies. Further study with a larger tumor cohort and longer follow-up will be necessary to determine if these findings are predictive of subsequent tumor shrinkage.

Abbreviations: VSs = vestibular schwannomas; SRS = stereotactic radiosurgery; CPA = cerebellopontine angle; IAC = internal auditory canal.