AJNR. American journal of neuroradiology最新文献

Background: The fate of ischemic tissue following a thromboembolic occlusion depends on the degree of hypoperfusion and the time from stroke onset to reperfusion. Little is known about the temporal dynamics of hypoperfusion and tissue damage. In this cross-sectional study, we compared how onset-to-imaging time is associated with volumetric versus intensity-based imaging markers.

Methods: We retrospectively analyzed acute stroke imaging from 288 CT and 275 MR examinations. Hypoperfusion and infarct core were estimated using the VEOcore software based on standard thresholds (Tmax > 6s, CBF < 30% or ADC < 620 × 10^-6 mm²/s). Tissue damage was quantified on NCCT using software-assisted ASPECTS, and contralaterally normalized signal intensities (NCCT HU, ADC, DWI-b0, DWI-b1000, CBF, Tmax) within the estimated infarct core. Associations with onset-to-imaging time were evaluated using multivariable linear regression adjusting for age, sex, occlusion site and MR field strength.

Results: CT patients were older (77 [65-83] vs. 72 [63-80] years, p<0.001) and imaged earlier (86 [64-149] vs. 102 [97-193] min, p<0.001) than MRI patients. Hypoperfusion and infarct core volumes were larger on CT (143 [96-189] vs 90 [40-156] mL; 24 [12-48] vs 17 [8-35] mL; both p<0.001). After adjustment, volumetric measures showed limited time-dependence: ASPECTS decreased by -0.33 points/h (p < 0.001) and ADC-core volume increased by +1.8 mL/h (p = 0.01), while perfusion volumes (CBF<30%, Tmax>6s, Tmax>10s) showed no significant change. Intensity measures changed markedly with time: NCCT intensity decreased by -1.1%/h (p < 0.001), ADC intensity by -0.69%/h (p = 0.001), whereas DWI-b0 increased by +2.3%/h and DWI-b1000 by +4.9%/h (both p < 0.001). Perfusion-based intensities were not significantly associated with time in either modality.

Discussion: In this cross-sectional analysis of multimodal data in acute ischemic stroke, tissue signal intensities showed stronger time-dependence than volumetric measures, supporting the view that infarct evolution reflects progressive tissue injury rather than consistent volumetric expansion. This suggests that "infarct growth rate" concepts may be more applicable to NCCT and DWI as parameters of tissue demise rather than to perfusion-based metrics.

Background and purpose: The understanding of long-term outcomes associated with branch-incorporated aneurysms treated using a flow diverter (FD) remains limited. This study evaluated long-term outcomes of flow diversion in patients with branch-incorporated aneurysms.

Materials and methods: We performed a retrospective analysis of a prospectively maintained database from five centers in South Korea. Patients who underwent FD placement for unruptured aneurysms with incorporated branch artery were identified; and long-term clinical and angiographic outcomes were evaluated.

Results: Sixty-five patients (median age, 61 years; male-to-female ratio, 15:50) with aneurysms (median size: 11.1 mm; median neck diameter: 7.2 mm) were identified. The median duration of clinical and imaging follow-up was 38 months (range: 13-75 months) and 26 months (range: 6-50 months), respectively. All patients exhibited favorable outcomes, with 63 having modified Rankin Scale (mRS) scores of 0-1 and 2 having an mRS score of 2. Aneurysm occlusion was achieved in 29.2% (n = 19) of patients at 6-8 months post-operatively, 53.8% (n = 35) at 12-18 months post-operatively, 84.0% (n = 42) at 19-48 months post-operatively, and 86.5% (n = 45) at > 48 months post-operatively. The incorporated branches were patent with aneurysm occlusion in 40% (n = 26), patent with aneurysm remnants in 36.9% (n = 24), and occluded with aneurysm occlusion in 23% (n = 15) of patients at the latest follow-up. No aneurysm recanalized after occlusion was achieved.

Conclusions: FD for branch-incorporated aneurysms demonstrated a low aneurysm occlusion rate in the short-to intermediate-term (6-12 months). However, long-term occlusion rates were comparable to those reported in the literature. In 23% of patients, the incorporated branches were occluded along with the aneurysm; none of these resulted in a permanent neurological deficit.

Background and purpose: Levodopa-induced dyskinesia (LID) remains one of the most challenging complications of long-term dopaminergic therapy in Parkinson's disease (PD), but reliable markers for identifying patients at higher risk remain uncertain. The purpose of this study was to determine whether longitudinal imaging trajectories derived from I-123 FP-CIT SPECT using latent class growth analysis (LCGA) show associations with LID occurrence, when considered with clinical characteristics.

Methods: 276 PD patients underwent I-123 FP-CIT scans at baseline, 1-year, 2-year, and 4-year follow-up periods. Specific binding ratios (SBRs) of the caudate and putamen were measured. LCGA was performed to classify patients into trajectory-based subgroups according to the patterns of dopaminergic denervation. Clinical variables including demographic characteristics, levodopa equivalent daily dose (LEDD), MDS-UPDRS scores, and motor subtypes (tremor-dominant, PIGD, and indeterminate), were assessed. Occurrence of LID within 4 years was the primary endpoint. Multivariate logistic regression was used to assess associations between baseline clinical/imaging variables and 4-year LID occurrence.

Results: LCGA identified two distinct trajectory classes among 276 patients, a gradual decline group (Class 1, n = 241, 87.3%) and a rapid decline group (Class 2, n = 35, 12.7%). Class 1 showed significantly lower baseline caudate (1.84 ± 0.46 vs 2.90 ± 0.37, p < 0.001) and putamen (0.70 ± 0.23 vs 1.33 ± 0.37, p < 0.001) SBRs compared with Class 2, but 4-year decline of SBRs was steeper in Class 2 (caudate -0.43 vs -0.92; putamen -0.20 vs -0.61). Class 2 was independently associated with LID in multivariate logistic regression (OR = 11.41, 95% CI 1.04-125.35, p = 0.047), along with the indeterminate motor subtype (OR = 10.56, 95% CI 1.809-61.682, p = 0.009). AUC of the multivariate model was 0.876 for 4-year LID occurrence.

Conclusions: Longitudinal imaging trajectories demonstrate contemporaneous associations with LID occurrence in PD and may provide clinically relevant insights when combined with clinical characteristics.

Introduction: DMSO (dimethyl sulfoxide) based liquid embolic agents have revolutionized the endovascular treatment of high-flow intracranial vascular malformations but can be associated with systemic and metabolic complications. Extensive safety data exists regarding the rates of such complication in adults and older children. However, relatively little published data is available on the safety profile in neonates, infants, and toddlers, which may limit uptake in the treatment of young children. We hypothesized that complication rates related to the use of these agents in young children are relatively similar to those reported in older children or adults.

Methods: A single-centre retrospective cohort study was undertaken of all paediatric neuro-interventional procedures utilizing DMSO-based liquid embolic agents in patients of age < 18 years at the time of their first procedure who underwent at least one embolization procedure between 1^st July 2022 and 30^th June 2025. The primary outcome was the rate of complications attributable to use of DMSO-based liquid embolic agents including systemic, metabolic, neurological, and technical complications. Subgroup analyses were performed comparing results between younger (neonates, infants, and toddlers: 0 days - 36 months) and older (3 - 18 years) age subgroups.

Results: A total of 66 embolization procedures were performed in 17 paediatric patients (female 6, male 11, age 2 days - 18 years, mean 4.1 years, median 2.0, SD 5.35). The most common indication for treatment was vein of Galen malformation (47 of 66 procedures, 71.2%), and 48 of 66 procedures (72.7%) were performed in the younger subgroup (0 days - 36 months). Complications attributable to use of DMSO-based liquid embolic agents occurred with 5 of 66 procedures (7.6%). Four complications occurred in the younger subgroup (4 of 48 procedures), but there was no statistically significant difference compared with the older subgroup (1 of 18 procedures) (p=0.22; Fishers exact test). These complications included one death, two transient neurological deficits, and two episodes of asymptomatic embolic migration to the lungs.

Conclusion: DMSO-based liquid embolic agents had a reasonable safety profile in neonates, infants, and toddlers, that was comparable to published rates in older children and adults.

Background: there is no consensus regarding the optimal imaging modality for assessing aneurysms treated with flow-diverters (FD).

Objectives: to evaluate the image quality of intravenous VasoCT (IV-VasoCT) in the follow-up of aneurysms treated with FD and to explore its potential for depicting braid stent deformation and vessel lumen modifications.

Material and methods: we retrospectively enrolled patients who underwent FD placement for the treatment of aneurysms, with post-treatment IV-VasoCT at 1-3 months and DSA at least 6 months. IV-VasoCT image quality assessment evaluated: vessel opacification, vessel border, stent radiopacity, stent/vessel contrast, movement artefacts. Braid stent and parent vessel findings were compared between IV-VasoCT and DSA in terms of: neointimal lining, stent foreshortening, fish-mouthing, bumping, braid collapse.

Results: 26 aneurysms were evaluated in 24 patients (F/M: 15/9), with a median age of 54.5 years (IQR: 47.0-59.0 years). The in-consensus image quality reading evaluated: vessel opacification as optimal in 19 cases (73.1%), vessel borders as well-defined in 17 (65.4%); stent radiopacity as well-defined in 25 (96.2%), stent/vessel contrast as optimal in 20 (76.9%). Compared to DSA, IV-VasoCT diagnosed 2/3 (66%) cases of neointimal lining, 2/2 (100%) of fish-mouth, 1/2 (50%) of foreshortening, 3/6 (50%) of bumping, 2/2 (100%) of braid collapse.

Conclusion: IV-VasoCT is feasible for the non-invasive follow-up of aneurysm treated with FD. It may depict modifications in braid stent and vessel neointimal lining, but the presence of coils may reduce its image quality because of artefacts.

Background and purpose: The optimal anesthetic regimen for the endovascular treatment (EVT) of stroke due to large vessel occlusion remains unclear. Patients with large infarct core on initial imaging constitute a specific subpopulation. The aim of this study was to investigate the impact of the anesthesia type during EVT on outcomes in this subpopulation.

Materials and methods: Data were extracted from the multicenter, randomized, controlled LASTE trial (n = 30 centers in France and Spain) that compared EVT plus best medical treatment versus best medical treatment alone in patients with large infarct core (ASPECTS = 0-5). In this post-hoc analysis, only patients who underwent EVT were included. Two study groups were defined: general anesthesia (GA), and conscious sedation and/or local anesthesia (CS-LA). The primary endpoint was the functional outcome, assessed with the modified Rankin Scale (mRS) at 3 months. Secondary endpoints included early neurological status, infarct extension at day 1, symptomatic intracranial hemorrhage, and mortality. Endpoints were investigated using univariate and multivariate analyses adjusted for pre-specified confounders.

Results: For this post-hoc analysis, 159 patients were included: 45 in the GA group and 114 in the CS-LA group. The functional outcome at 3 months was not different between groups: median mRS score = 5 (IQR: 3-6) in the GA and 4 (IQR: 3-6) in the CS-LA group (adjusted OR = 0.78; 95% CI 0.52 - 1.18). However, in the GA group, the National Institutes of Health Stroke Scale score significantly worsened between admission and day 1 [mean difference= -3.8 (-6.6 to -1.0), p=0.007], infarct volume extension was more severe [mean difference: -26.5 ml (-50.2 to -2.9), p=0.028], and parenchymal hematoma was more frequently detected. Between-group differences in early neurological improvement, symptomatic intracranial hemorrhage, and mortality were not significant.

Conclusion: In this post-hoc analysis of the LASTE trial data, we detected potential signals of a GA detrimental effect in patients with large infarct core on baseline imaging. Larger studies are necessary to confirm this finding.

Background: The glymphatic system, essential for metabolic waste clearance and brain homeostasis, is vulnerable to disruption following traumatic brain injury (TBI). There is a pressing need for practical and robust methods to assess glymphatic function after TBI, as well as for other neurologic disorders. Diffusion tensor imaging along the perivascular space (DTI-ALPS) might have value in quantifying glymphatic dysfunction.

Purpose: Our aim was to consolidate existing evidence to determine differences in DTI-ALPS values between TBI patients and healthy controls (HCs).

Data sources: All studies utilizing the DTI-ALPS index and reporting its mean and standard deviation in both TBI patients and healthy controls were identified through searches of PubMed, Embase, Scopus, and Web of Science from inception to August 8, 2025.

Study selection: Eleven studies comprising 694 patients with TBI, and 503 HCs were included.

Data analysis: Meta-analysis was conducted using a random-effects model. Standardized mean differences (Hedges' g) were used as the effect size measure. Pooled correlations between DTI-ALPS indices and demographic variables were evaluated. Heterogeneity was assessed using Higgins' I² statistic. Subgroup analyses, meta-regression, and sensitivity analyses were performed to identify potential sources of heterogeneity, and publication bias was examined using funnel plots and Begg's test.

Data synthesis: DTI-ALPS values were found to be significantly reduced in TBI patients compared to HCs (Hedges' g = -0.77; 95% CI: -1.38 to -0.15; I²=93%). DTI-ALPS showed no significant correlation with age or Glasgow Coma Scale scores. Subgroup analyses revealed larger effect sizes in single-shell studies and those with higher methodological rigor. Meta-regression showed a larger decrease in DTI-ALPS values in TBI patients over time (β=-0.01, p=0.03). No substantial publication bias was detected (p=0.12).

Limitations: Our meta-analysis is limited by substantial heterogeneity and the small number of included studies.

Conclusions: TBI is associated with significantly reduced DTI-ALPS values, with more prominent deteriorations over the long term, supporting its potential as a biomarker of glymphatic impairment. However, methodological heterogeneity emphasizes the need for standardized protocols and longitudinal studies to establish clinical utility.

Objectives: 7T MRI enhances lesion detection in epilepsy but is limited by radiofrequency transmission field (B1+) inhomogeneity and long scan times. Recent advancements in dynamic parallel transmission and deep-learning-based reconstructions offer promising solutions. We aimed to optimize an enhanced 7T epilepsy protocol incorporating these innovations and evaluate real-world benefits compared to standard 7T epilepsy protocol.

Materials and methods: We retrospectively compared 40 consecutive brain MRIs acquired using a standard 7T epilepsy protocol to 40 MRIs obtained with an enhanced protocol with dynamic parallel transmission and deep-learning-based k-space reconstructions. Quantitative metrics for comparison included image noise, signal homogeneity (coefficient of variation), and resolution/time trade-offs.

Results: The enhanced protocol demonstrated significant improvements in resolution, scan time, noise levels, and image homogeneity. Edge-enhancing gradient echo and magnetization-prepared rapid gradient echo with 2 inversions sequence exhibited a 57.8% reduction in voxel volume while reducing scan time by 33.0% and improving image homogeneity (P=.002) without a significant change in noise (P=0.09). Deep-learning-based reconstruction of coronal T2 turbo spin echo resulted in a 25.7% reduction in noise (P<.001), and patient-specific B1+ shimming achieved homogeneity comparable to dielectric pads. Sampling perfection with application-optimized contrasts using a different flip angle evolutions fluid-attenuated inversion recovery had reduced noise (P<.001), enhanced homogeneity (P<.001), and halved voxel size while maintaining similar scan time. Deep-learning-based echo planar imaging susceptibility-weighted imaging improved acquisition time by 56.5% with a 20.5% reductionin noise (P=.001). Despite increased resolution and parallel transmission use, overall scan time was less than 25 minutes, half the duration recommended by the 7T Epilepsy Task Force.

Conclusions: Integration of dynamic parallel transmission and deep-learning-based reconstructions enhances image resolution, reduces scan time, and improves image homogeneity, addressing barriers to routine clinical implementation of 7T MRI. These advancements may improve lesion conspicuity and contribute to better outcomes for patients with epilepsy.