Clinical Neuroradiology最新文献

Purpose: Ring-enhancing lesions (RELs) of the brain are frequently encountered but often pose diagnostic challenges. In tropical countries like India, neurocysticercosis (NCC) and tuberculomas are among the most common causes of intracranial RELs. Accurately distinguishing between the two is critical for appropriate treatment. To our knowledge, no prior study has combined synthetic MRI-derived parameters with DCE-MRI metrics to address this specific diagnostic dilemma. Out objective is to assess the diagnostic utility of relaxometry metrics from synthetic MRI, magnetization transfer ratio (MTR), and the volume transfer constant (K-trans) from dynamic contrast-enhanced (DCE) MRI in differentiating NCC from tuberculomas.

Methods: This prospective study included 53 patients with ring-enhancing brain lesions (24 NCC, 29 tuberculomas). All underwent conventional MRI, synthetic MRI, MT imaging, and DCE-MRI. Quantitative parameters (R1, R2, proton density, MTR, and K‑trans) were extracted from the lesion core, wall, and surrounding edema and analyzed using non-parametric statistical tests.

Results: Tuberculomas demonstrated significantly higher pre-contrast R1 and R2 values in the core than NCC. A core R2 cutoff of ≤ 15.90 s⁻¹ yielded 100% sensitivity and specificity. Wall MTR was also higher in tuberculomas (cutoff ≥ 0.22; 86% sensitivity, 88% specificity, positive predictive value (PPV) and negative predicative values (NPV) of 89.3% and 84.0% respectively). K‑trans values in the wall were elevated in tuberculomas, with a cutoff of ≥ 1.91 showing 79.31% sensitivity, 79.17% specificity, 82% PPV and 76% NPV.

Conclusion: Synthetic MRI-derived relaxometry and MTR provide objective, quantitative biomarkers to differentiate NCC from tuberculomas. The pre-contrast core R2 value emerged as the most discriminative parameter, enhancing diagnostic accuracy and supporting informed clinical decision-making.

Background and objective: In-stent restenosis (ISR) is an important factor affecting the long-term efficacy of stenting for intracranial atherosclerotic stenosis (ICAS). We aimed to investigate the risk factors of ISR by analyzing the clinical features, angiography-based hemodynamic parameters, and vascular morphology.

Methods: Patients with severe symptomatic ICAS undergoing stenting were retrospectively screened. The vascular morphology was described by angle, relative length (RL), triangulation index (TI). Hemodynamic parameters were assessed by quantitative digital subtraction angiography. Four regions of interest (ROIs) were delineated near the lesion. Relative time to peak (rTTP) was the difference in TTP between ROIs. Logistic regression was performed to explore the risk factors of ISR.

Results: Of the 312 patients, 106 (median [IQR] age, 61.0 [53.8-66.3] years; 83 [78.3%] male) were ultimately included, of whom 22 patients (20.8%) developed ISR, with a median follow-up time of 6.6 (6.1-8.8) months. Multivariate logistic analysis showed that residual stenosis (adjusted OR = 1.107, p = 0.007), monocyte to high-density lipoprotein cholesterol ratio (MHR) (adjusted OR = 1.031, p = 0.032), hyperglycemia (adjusted OR = 5.695, p = 0.015), post-stenting RL (adjusted OR = 0.802, p = 0.032) and trans-stenotic rTTP_4 - 1 difference (adjusted OR = 6.995, p = 0.009) were significantly associated with ISR. The final predictive model for ISR presented strong predictive capabilities (AUC = 0.867, 95%CI 0.794-0.940).

Conclusions: Angiographic hemodynamic parameters, vascular tortuosity, and MHR are significant risk indicators associated with ISR. The developed model shows strong potential for identifying high-risk patients.

Purpose: To investigate the relationship between intracranial pressure (ICP), anterior pituitary hormones, and structural brain changes in women with idiopathic intracranial hypertension (IIH).

Methods: Eighteen women with therapy-refractory IIH underwent lumbar puncture, endocrine assessment, and high-resolution brain MRI. Serum levels of pituitary hormones were correlated with ICP and radiological parameters including pituitary volume, flattening, and optic nerve (ON) and optic nerve sheath (ONS) volume. Group comparisons and partial correlations were used to evaluate associations.

Results: ICP showed a significant positive association with thyroid-stimulating hormone (TSH) levels (r = 0.628, p = 0.016), and a significant negative association with growth hormone (GH) (r = -0.602, p = 0.023). Regarding structural parameters, only the volume of the right ON showed a strong positive association within the subgroup with elevated ICP (r = 0.90, p = 0.005). Correlations between ONS volumes and ICP in the normal pressure subgroup narrowly missed statistical significance. TSH was the only hormone showing a significant association, with higher TSH levels relating to larger pituitary volume in the normal ICP subgroup (r = 0.88, p = 0.020), but not in the elevated ICP subgroup.

Conclusion: Our exploratory findings suggest potential interactions between ICP, endocrine markers, and structural MRI measures. However, due to the limited sample size and variability in endocrine parameters, the results should be interpreted cautiously and considered hypothesis generating rather than clinically directive. Larger studies are needed to determine whether endocrine MRI associations hold true and whether they have diagnostic or clinical relevance.

Purpose: The aim of the study was to investigate whether the ventriculoperitoneal (VP) shunt valve setting can be reliably assessed using maximum intensity projection (MIP) reconstructions from non-contrast, full-dose head CT scans, and how this method performs in comparison to conventional lateral skull radiographs.

Methods: This retrospective study included 41 adult patients (mean age 59 ± 25 years) with Codman Certas programmable VP shunt valves who underwent lateral skull X‑ray and a same-day, non-contrast head CT scan between January and July 2024. From the CT data, MIP reconstructions of the valve region were generated. Three neuroradiologists, blinded to each other's assessments, independently rated valve settings and image quality using a 5-point Likert scale. Mean reconstruction time was recorded. Radiation dose data were extracted from institutional dose-monitoring software.

Results: Valve settings were identifiable in all 44 CT/X-ray image pairs, with 95% agreement between MIP and X-ray readings. MIP reconstructions were successfully generated (median CTDI_vol 35.34 mGy (30.42; 40.32); mean reconstruction time 70 s). Image quality was rated lower for MIP (median 2 [IQR 2]) than for X‑ray (median 4 [IQR 1]; p < 0.001). In 45% of cases scanned with photon-counting CT, MIP quality was significantly higher (median 3 vs. 1; p < 0.001). Inter-reader reliability was good for MIPs (ICC = 0.82) and excellent for X‑rays (ICC = 0.97).

Conclusion: MIP reconstructions from non-contrast head CT allow reliable VP shunt valve setting assessment and may reduce the need for additional radiographs, especially when advanced CT systems are used.

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.