Clinical Neuroradiology最新文献

Purpose: Digital subtraction angiography (DSA) is the gold standard for evaluating outcomes after flow diverter (FD) stent placement, though its invasive nature presents limitations. Time-of-flight magnetic resonance angiography (TOF-MRA) is commonly used as a non-invasive alternative; however, it is susceptible to artifacts related to magnetic susceptibility and phase dispersion. Recently, Pointwise Encoding Time Reduction with Radial Acquisition (PETRA)-MRA, which employs an ultra-short echo time technique, has emerged as a promising option for post-endovascular imaging. This study aimed to quantitatively assess and compare the signal properties of PETRA-MRA and TOF-MRA in patients following FD treatment, in order to minimize observer-dependent variability.

Methods: A retrospective review was conducted on patients treated with a Pipeline Flex with Shield Technology stent for internal carotid artery aneurysms between April 2021 and March 2024. All patients underwent both TOF-MRA and PETRA-MRA scans on the day after treatment, using a 3‑T MRI system. Signal intensities were evaluated in the FD, contralateral internal carotid artery (ICA), aneurysm, and background across three slices for each patient. For aneurysm analysis, the slice with the largest visible aneurysm diameter was selected. Contrast-to-noise ratios (CNR) were computed in relation to the background signal, and signal intensity ratios (SIR) were calculated with reference to the contralateral ICA. These metrics were then compared between TOF-MRA and PETRA-MRA.

Results: The analysis included 21 patients (mean age 60.2 years; 14 female), with 7 (33%) receiving additional coiling. The average aneurysm diameter was 9.2 ± 5.6 mm. PETRA-MRA yielded significantly higher CNR values for both the FD (3.80 ± 1.21) and aneurysm (8.04 ± 5.79) compared with TOF-MRA (FD 2.51 ± 0.95, p < 0.001; aneurysm 3.92 ± 2.41, p = 0.001). Similarly, SIR values were notably greater with PETRA-MRA for the FD (0.44 ± 0.07 vs. 0.35 ± 0.08, p < 0.001) and the aneurysm (0.95 ± 0.19 vs. 0.62 ± 0.23, p < 0.001).

Conclusions: Compared to TOF-MRA, PETRA-MRA provided higher CNR and SIR in the evaluation of both FD and aneurysm visualization. These findings indicate that PETRA-MRA is a promising noninvasive technique for early postprocedural assessment after FD treatment.

Background: Unruptured intracranial aneurysms are a common and can have devastating outcomes if ruptured. Flow diversion has expanded treatment options, especially for wide-necked and blister aneurysms. Yet, optimal follow-up retreatment strategies in case of treatment failure remain unclear. A DELPHI consensus was initiated to understand current practice in aneurysm management after flow diverter treatment.

Methods: This DELPHI consensus was conducted during the 5 T Think Tank, following a scoping literature review. Experts discussed the results, responded to iterative questionnaires, which started with four open-ended questions, and concluded with ten closed-ended questions.

Results: Of the 40 attendees, 24 participants (60%) identified as experts in flow diversion and participated in the DELPHI process, which involved a literature search and three DELPHI rounds. Consensus was reached on performing the first assessment of the flow diverter during the procedure using cone-beam CT (77.8%), and on timing of the first follow up (at 6 months, 70.8%). For follow-up timing, an annual (57%) or semi-annual (43%) schedule was favored. No preference emerged for the follow-up imaging modality, with slight preferences for MRA (29%), followed by DSA (25%), DSA + MRA (21%), CTA (17%), and DSA + CTA (8%). Aneurysm growth (> 2 mm) was identified as a key criterion for retreatment. It was thought that combining clinical and angiographic metrics should be a key research priority, as it could potentially improve retreatment decision making compared to a purely angiographic outcome.

Conclusion: This DELPHI consensus highlights the complexity of decision-making for unruptured intracranial aneurysms. Despite these challenges, there was consensus among international experts on follow-up timing and decision drivers for retreatment.

Purpose: Intracranial aneurysms are a major cause of hemorrhagic stroke, often requiring endovascular intervention. The Woven EndoBridge (WEB) device offers a minimally invasive solution for wide-neck bifurcation aneurysms and typically requires only single antiplatelet therapy, reducing bleeding risks associated with dual regimens. However, long-term clinical and angiographic data remain limited.

Methods: This single-center, retrospective study analyzed 247 patients treated with the WEB device between January 2013 and December 2021, with clinical and imaging follow-up through June 2024. Demographics, aneurysm characteristics, procedural outcomes, and retreatment rates were evaluated. A competing risk model was applied to identify factors associated with retreatment.

Results: The cohort included 247 patients (mean age: 63 years; 70% female) with 266 broad-based intracranial aneurysms. The overall retreatment rate was 12.8%, most occurring within the first year. Subgroup analysis revealed no significant differences based on aspect ratio (< 1.6 vs. ≥ 1.6) or device diameter (< 0.9 mm vs. ≥ 0.9 mm). Patients treated after 2018 had significantly lower retreatment rates (HR: 0.31; 95% CI: 0.13-0.71; p = 0.006), likely reflecting greater operator experience and introduction of the WEB17 model.

Conclusion: The WEB device demonstrates durable aneurysm occlusion with a low long-term retreatment rate. Improved outcomes after 2018 suggest an effect of the learning curve and device refinement. Early imaging follow-up and continued operator training remain essential to optimize procedural success.

Purpose: The impact of distal guide catheter placement on clinical outcomes for endovascular thrombectomy (EVT) in large vessel occlusion (LVO) stroke remains uncertain. This systematic review and meta-analysis aims to evaluate the efficacy and safety of distal versus proximal guide catheter placement for EVT.

Methods: Following PRISMA guidelines, we systematically searched PubMed, EMBASE, and the Cochrane Library from database inception to June 15, 2025 to identify studies that directly compared clinical outcomes of distal versus proximal placement of guide catheter. We pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs) using a random-effects model. The study protocol was registered on PROSPERO (CRD42024598147).

Results: A total of seven observational studies involving 1534 patients were included. Distal position of guide catheter was associated with significantly higher likelihood of first pass effect (OR, 2.16 [95% CI, 1.71-2.74]; P < 0.00001), successful recanalization (OR, 2.37 [95% CI, 1.27-4.42]; P = 0.007), and final mTICI 3 (OR, 1.53 [95% CI, 1.16-2.01]; P = 0.002). Symptomatic intracranial hemorrhage was comparable between the two groups (OR, 0.76 [95% CI, 0.38-1.51]; P = 0.43).

Conclusion: Distal placement of guide catheter appears to be beneficial for EVT in LVO stroke, with improved procedural outcomes than those with proximal position.

Objectives: Determining the involvement of specific peripheral nerves (PNs) in the upper limb associated with signs of muscle denervation can be challenging. This study aims to develop, compare, and validate various large language models (LLMs) to automatically identify and establish potential relationships between denervated muscles and their corresponding PNs.

Materials and methods: We collected 300 retrospective MRI reports in Spanish from upper limb examinations conducted between 2018 and 2024 that showed signs of muscle denervation. An expert radiologist manually annotated these reports based on the affected peripheral nerves (median, ulnar, radial, axillary, and suprascapular). BERT, DistilBERT, mBART, RoBERTa, and Medical-ELECTRA models were fine-tuned and evaluated on the reports. Additionally, an automatic voting system was implemented to consolidate predictions through majority voting.

Results: The voting system achieved the highest F1 scores for the median, ulnar, and radial nerves, with scores of 0.88, 1.00, and 0.90, respectively. Medical-ELECTRA also performed well, achieving F1 scores above 0.82 for the axillary and suprascapular nerves. In contrast, mBART demonstrated lower performance, particularly with an F1 score of 0.38 for the median nerve.

Conclusions: Our voting system generally outperforms the individually tested LLMs in determining the specific PN likely associated with muscle denervation patterns detected in upper limb MRI reports. This system can thereby assist radiologists by suggesting the implicated PN when generating their radiology reports.

Purpose: This study aimed to evaluate the diagnostic performance of 3D T1-weighted black-blood (T1W BB) MRI compared to 3D T1-weighted turbo field echo (T1-TFE) in diagnosing facial neuritis (FN) and to investigate its role in disease monitoring.

Materials and methods: 22 patients with acute idiopathic FN were included in this prospective study. All patients underwent MRI within the first week of clinical presentation including 3D T1W BB and 3D T1-TFE sequences. Two neuroradiologists independently analyzed six facial nerve segments, evaluating contrast enhancement using a three-point grading scale (0-2). Diagnostic accuracy, sensitivity, specificity, and area under the curve (AUC) were compared between the two sequences. Follow-up MRI was performed in 8 patients to monitor temporal changes in nerve enhancement, and these findings were analyzed in relation to House-Brackmann (HB) scores.

Results: The sensitivity, specificity, and accuracy for FN detection were 97.7%, 93.2%, and 95.5% for 3D T1W BB, compared to 86.4%, 97.7%, and 92% for 3D T1-TFE, respectively. Sensitivity was significantly higher with 3D T1W BB (p < 0.05), while AUCs were higher but not significant for both readers. Mean enhancement grades in all affected nerve segments were significantly higher on 3D T1W BB (p < 0.05). Follow-up imaging showed enhancement reduction in 87.5% of patients, correlating with HB score improvements. Enhancement grades significantly correlated with HB scores on T1W BB but not on T1-TFE.

Conclusion: 3D T1W BB has comparable diagnostic performance with 3D T1-TFE for diagnosing FN and can be used as an effective tool in confirming the diagnosis and in follow-up.

Background: Carotid artery stenting (CAS) using the 7F Optimo balloon guide catheter (BGC) allows for smooth navigation and facilitates proximal flow control. However, this method may allow antegrade flow in the internal carotid artery (ICA). This study aims to identify predictors of antegrade flow during CAS with the common carotid artery (CCA) occlusion.

Methods: We retrospectively analyzed 102 lesions treated with CAS using the 7F Optimo BGC and distal filter protection. The ICA flow pattern was assessed via contrast injection during CCA occlusion.

Results: Antegrade flow in the ICA was observed in 22 lesions (22%). Compared with lesions where ICA flow control (stagnation or reverse flow) was achieved, the external carotid artery (ECA) diameter was significantly larger (4.4 ± 0.7 mm vs. 3.6 ± 1.2 mm, p < 0.001), and the minimum lesion diameter was significantly larger (3.2 ± 1.2 mm vs. 2.1 ± 1.0 mm, p < 0.001). Multivariate analysis identified a minimum lesion diameter ≥ 2.1 mm (OR 4.8, 95% CI 1.44-16.1; p = 0.01) and an ECA diameter ≥ 4.2 mm (OR 3.2, 95% CI 1.08-9.09; p = 0.04) as independent predictors of antegrade flow. High-intensity spots in postoperative diffusion-weighted magnetic resonance imaging and the incidence of ischemic events were not significantly different between both groups.

Conclusions: Lesions with a minimum lesion diameter ≥ 2.1 mm or an ECA diameter ≥ 4.2 mm may exhibit antegrade ICA flow with BGC regardless of CCA occlusion, suggesting that an additional distal filter may help reduce embolic risk.

Purpose: The central vein sign (CVS) is a promising imaging biomarker for multiple sclerosis (MS) diagnosis. While isotropic T2* at 3 T and 7 T has demonstrated high diagnostic performance, its utility at 1.5 T remains unclear. This study evaluates the performance of unenhanced FLAIR-T2* fusion at 1.5 T compared to 3 T in MS participants.

Methods: This prospective observational study included 20 MS patients and 20 control subjects. Each participant underwent unenhanced isotropic Epi-T2* and isotropic FLAIR (0.8 mm voxel size) at both 1.5 T and 3 T. Subsequently, the derived isotropic T2* and FLAIR were combined to create the final FLAIR-T2* fusion in both magnetic field strengths. Two independent raters assessed the CVS status of white matter (WM) lesions using NAIMS criteria. WM lesions were classified as CVS+ or CVS-, and two methods-select-n* and CVS+ proportion-were applied. Sensitivity and specificity were computed, and CVS performance was compared across WM lesion locations.

Results: Among eligible WM lesions (MS: 258; controls: 255), the mean CVS+ lesion proportion per participant was 66.9 ± 15.4% for 1.5 T FLAIR-T2* and 77.0 ± 13.6% for 3 T FLAIR-T2* (p < 0.01). At a 40% threshold, 1.5 T FLAIR-T2* achieved 90% sensitivity and 95% specificity, while 3 T FLAIR-T2* achieved 100% sensitivity and 95% specificity. The Select-6* method resulted in only one MS patient being misclassified at both field strengths. 3 T FLAIR-T2* detected more CVS+ lesions in deep WM (87.5% vs. 57.1%, p = 0.05).

Conclusion: 1.5 T FLAIR-T2* fusion demonstrates high performance in CVS assessment, although slightly outperformed by 3 T FLAIR-T2*. The select-6* method may enhance 1.5 T performance, supporting its feasibility for CVS evaluation.

Purpose: Visualizing the culprit perforating artery in subcortical infarction using in vivo imaging is challenging. We aimed to identify the culprit perforating arteries in subcortical infarctions and assess their morphology using an image fusion technique.

Methods: We retrospectively reviewed consecutive patients who had an ischemic stroke in the anterior circulation perforating area (caudate nucleus, lentiform nucleus, internal capsule, corona radiata, or centrum semiovale) and underwent three-dimensional rotational-angiography (3D-RA) and 3D fluid-attenuated inversion recovery MRI. Images were registered using an original fusion software. The spatial relationship between the infarction and culprit perforating artery and its morphological characteristics were analyzed in the fusion images. Stenosis was defined as > 50% luminal narrowing or a focal intraluminal defect in the perforating artery.

Results: Of 118 patients, the culprit perforating artery was identified in 52 patients (44%); They tended to have younger age and had a higher baseline NIHSS score and higher prevalence of infarcts in the lentiform nucleus than did those without identified culprit perforating artery. Among the 44 patients with assessable morphology of the culprit perforating artery, 27 (61%) exhibited stenosis in the proximal segment. Atrial fibrillation was more frequent in patients without stenosis in the proximal segment of the culprit perforating artery than in those with stenosis (29% vs. 4%, P = 0.03).

Conclusion: The 3D-RA and MRI fusion technique enables identification of the culprit perforating arteries in subcortical infarctions, especially in the lentiform nucleus. Morphological features of the culprit perforating artery may be associated with the etiological mechanism of stroke.