Neuroradiology最新文献

Purpose: Although the T1w/T2w ratio was introduced as a proxy for myelin, it may reflect broader aspects of brain tissue health. The recently introduced T1w/FLAIR ratio has yet to be evaluated in relation to biological and clinical markers. This study investigates its association with myelin water fraction (MWF), diffusion MRI (dMRI), and cognitive performance, and explores whether alternative weightings of the ratio improve these associations.

Methods: 36 women were retrospectively included from a previous study with neuropsychological testing and 3T MRI. Spearman correlations assessed associations between the T1w/FLAIR ratio and MWF, fractional anisotropy (FA), mean diffusivity (MD), neurite density index (NDI), orientation dispersion index (ODI), and fraction of isotropic diffusion compartment (FISO). Region-specific and overall correlations were evaluated across 36 white matter regions, lesions, total white matter, and cortical and deep gray matter. Associations with attention, memory, and processing speed were examined. Least squares regression was used to derive an optimally weighted ratio based on MWF, and analyses were repeated using this weighted ratio.

Results: Significant correlations between the T1w/FLAIR ratio and MWF and/or dMRI measures were found in six out of 40 regions. Across regions and subjects, the ratio showed weak overall correlations (r < 0.5) with MWF, FA, NDI, and FISO. A significant positive correlation with memory was only observed within lesions. The optimal weighting favored a stronger contribution from the T1w signal but resulted in only slightly stronger correlations.

Conclusion: Our results support the interpretation of T1w/FLAIR ratio as a general marker of tissue health rather than a specific measure for myelin.

Purpose: To determine whether relaxometry assessment using synthetic MRI (SyMRI) can predict meningioma consistency.

Methods: Eighteen patients with histologically confirmed meningioma were included, and all patients underwent quantitative MRI on a 3T MRI system using a 2D multi-dynamic multi-cho sequence. Quantitative MRI software version 11.3 (SyntheticMR AB, Linköping, Sweden) was used to generate quantitative maps of T1, T2 relaxation times and proton density (PD). Regions of interest were manually placed over all tumor slices to evaluate three parameters (T1, T2, PD). Comparing with the conventional method, relative values of the tumor-to-thalamus signal intensity ratio on the non-contrast T1-weighted image (T1R) and T2-weighted image (T2R) and apparent diffusion coefficients generated from b-values (0 and 1000 s/mm²) of the diffusion-weighted image were also evaluated. The 10^th, 25^th, 50^th, 75^th, and 90^th percentiles and mean values were calculated using histogram analysis. Meningioma consistency was intraoperatively assessed by neurosurgeons using a standardized 5-point scale, with tumors classified as soft (scores 1-2) or hard (scores 3-5). The Mann-Whitney U test and receiver operating characteristic analysis were performed.

Results: Soft meningiomas showed significantly longer T1 and T2 relaxation times and higher PDs than hard meningiomas (median value, p-value: 2701 vs. 1721 ms, p = 0.0009 for T1; 111 vs. 94 ms, p = 0.0047 for T2; 92 vs. 85%, p = 0.0092 for PD, respectively). The 90^th percentile of T1 relaxation time exhibited the highest diagnostic performance for differentiating soft from hard meningiomas.

Conclusion: Relaxometry assessment offers a reliable method for predicting meningioma consistency that can optimize surgical planning.

Background: Pretreatment determination of histological differentiation grade is critical for prognostic evaluation in laryngeal and hypopharyngeal squamous cell carcinoma (LHSCC). This study aimed to develop a contrast-enhanced CT (CECT)-based Vision Transformer (ViT) model for noninvasive evaluation of histological grades in LHSCC.

Methods: In this retrospective multicenter study, a total of 1,648 LHSCC patients who underwent CECT scans were enrolled from three hospitals in this study. Participants were divided into a training cohort (n = 1,239), an internal validation cohort (n = 310) from one hospital, and an external validation cohort (n = 99) from the other two hospitals. The diagnostic model integrates a pre-trained ViT for CECT feature extraction and an XGBoost classifier for prediction. The model's predictive performance was evaluated using the area under the curve (AUC), decision curve analysis (DCA), and calibration curve.

Results: The ViT model achieved AUCs of 0.887 (95%CI: 0.848-0.927) in internal validation and 0.796 (95%CI: 0.693-0.899) in external validation cohorts, significantly outperforming the conventional radiomics model (AUCs: 0.775, 95%CI: 0.714-0.837 and 0.544, 95%CI: 0.388-0.699; p < 0.001 and 0.002, respectively). Clinically, DCA demonstrated superior clinical utility, while calibration curves showed excellent prediction reliability. Gradient-weighted Class Activation Mapping visualization identified CT image regions most influential for the model's predictions, providing interpretability for clinical decision-making.

Conclusion: The ViT-based deep learning model developed in this study using CECT demonstrated excellent predictive performance for histological grading of LHSCC, with promising application for patient prognosis assessment.

Purpose: Hyperdense middle cerebral artery sign (HMCAS) is a phenomenon highly specific for acute ischaemic stroke (AIS) that can be found in brain non-contrast computed tomography (NCCT). Previous studies concerning its association with outcomes of patients undergoing mechanical thrombectomy (MT) are inconclusive. Our aim was to assess the relationship between HMCAS presence and long-term outcomes of AIS patients undergoing MT.

Methods: The study included anterior circulation AIS patients treated with MT in the University Hospital in [ANONYMIZED] from 2019 to 2021, in whom admission NCCT and one-year follow-up were available. The clinical, laboratory and imaging data, as well as following outcomes: the occurrence of successful recanalization [defined as modified treatment in cerebral infarction (mTICI) score 2b-3], haemorrhagic complications (ICH), 90-day and 365-day rates of mortality and good functional outcome [defined as modified Rankin Scale (mRS) score 0-2] were compared between groups of patients with and without HMCAS on initial NCCT. The association of HMCAS presence with the abovementioned outcomes was assessed using multivariate logistic regression analysis.

Results: Among 359 MT-treated patients with anterior circulation AIS, HMCAS was found in 244 (67.97%). The presence of HMCAS was independently associated with good functional outcome at 365 days (OR 1.956, 95% CI = 1.152-3.317, p = 0.013) as well as lower 90-day and 365-day mortality (OR = 0.464, 95% CI = 0.2517-0.856; p = 0.014 and OR 0.543, 95% CI: 0.313-0.940, p = 0.029, respectively).

Conclusion: The presence HMCAS on admission NCCT is associated with favourable long-term outcome in AIS patients undergoing MT.

Purpose: Visible perivascular spaces of cerebral white matter at magnetic resonance imaging (MRI) were in several studies proposed to be an integral part of brain-wide perivascular clearance pathways, and their enlargement could therefore serve as markers of perivascular clearance dysfunction. We studied whether MRI-visible perivascular spaces in subcortical white matter communicate with subarachnoid cerebrospinal fluid (CSF).

Methods: MRI-visible perivascular spaces of the basal ganglia served as controls. Intrathecal 0.5 mmol gadobutrol was utilized as CSF tracer, and T1-weighted MRI was performed before, and at multiple time points after (3, 6, 24 and 48 h) injection. Perivascular spaces with diameter ≥ 2 mm were included in the analysis, and a circular region of interest was placed manually within one perivascular space and in adjacent brain parenchyma of each region.

Results: The study included 27 symptomatic individuals undergoing clinical work-up of various CSF circulation disorders, but in whom no treatable condition was found. Perivascular spaces of both white matter and basal ganglia enhanced with intrathecal gadobutrol, confirming CSF exchange with perivascular spaces. While perivascular spaces of basal ganglia enhanced most with peak at 6 h (233.2% [34.9 to 431.5%]) (p < 0.01), coinciding with peak enhancement in subarachnoid CSF, perivascular spaces of white matter enhanced less and more slowly with peak at 48 h (159.1% [37.9 to 280.3%]) (p < 0.01).

Conclusions: The various degrees of CSF exchange with MRI-visible subcortical perivascular spaces suggest these may be dilated for different reasons, therefore questioning their validity as markers of perivascular clearance function.

Background: Aneurysm wall enhancement (AWE) is a potential imaging biomarker that can be used to identify intracranial aneurysms with an increased risk of rupture. Factors and mechanisms causing intracranial aneurysms to rupture or progress differ between women and men. Thus, we performed a cross-sectional and prospective cohort study to identify the risk factors predicting AWE in men and women.

Methods: Consecutive patients with unruptured intracranial aneurysms were prospectively recruited from September 2022 to September 2024. Baseline characteristics were collected through a standard questionnaire. Multivariate logistic regression was performed to assess the predictors of aneurysmal wall enhancement in men and women.

Results: A total of 332 patients with 435 intracranial aneurysms were included. In the multiple logistic regression analysis, obesity (OR = 2.88, 95% CI 1.06-7.81, P = 0.038), the history of hypertension (OR = 2.76, 95% CI 1.16-6.57, P = 0.022) and younger age (OR = 0.96, 95% CI 0.93-1.00, p = 0.035) were independent risk factors for AWE in men. Meanwhile, drinking habit (OR = 2.64, 95% CI 1.09-6.41, P = 0.032), the family history of intracranial aneurysm (OR = 4.01, 95% CI 1.21-13.36, P = 0.024) and older age (OR = 1.04, 95% CI 1.01-1.07, P = 0.009) were independent risk factors for AWE in women.

Conclusion: This study clearly demonstrates a significant sexual dimorphism in the risk factors associated with AWE. These findings underscore the necessity for sex-specific risk stratification models for intracranial aneurysm management, suggesting that men and women have specific lifestyle interventions to prevent the progression or rupture of intracranial aneurysms.

Background and purpose: Stent-assisted coiling has revolutionized the treatment of wide-neck intracranial aneurysms. Several technical improvements have since emerged, including enhanced deliverability, low-profile designs, and reduced surface thrombogenicity. This study aimed to assess the real-world feasibility, safety, and efficacy of the pEGASUS-HPC device for intracranial aneurysms.

Materials and methods: This independent, multicenter, retrospective observational study evaluated patients treated with pEGASUS-HPC stent-assisted coiling between April 2022 and December 2024. Data on procedural outcomes, complications (technical and clinical), and imaging follow-up were analyzed.

Results: Ninety-nine aneurysms (30 ruptured (30.3%), 69 unruptured (69.7%)) in 98 patients (58 female (59.2%), 40 male (40.8%) were treated using 130 pEGASUS-HPC stents. The successful deployment rate was 97%. Device-related mortality and morbidity were 2% and 1%, respectively. Ischemic complication rates did not significantly differ between acute and elective cases or between single and dual antiplatelet therapy groups. Adequate occlusion (Raymond-Roy Class I-II) was achieved in 95% immediately post-procedure and 93% at follow-up (median 240 days).

Conclusions: The pEGASUS-HPC stent shows high feasibility, safety, and effectiveness in the treatment of intracranial aneurysms. Further research is warranted to assess the impact of its surface coating, especially in emergency settings.

Background: Ependymal enhancement is an uncommon but diagnostically challenging MRI finding with a wide range of aetiologies.

Purpose: This pictorial essay presents an algorithmic approach to its differential diagnosis.

Results: We categorize the ependymal enhancement into three main etiologic groups: infectious disorders, non-infectious inflammatory disorders and tumors, highlighting specific demographic, clinical, and imaging findings that are crucial for diagnosis. We provide two diagnostic algorithms according to the patient's immune status, since it is paramount in determining the differential diagnosis. For immunosuppressed patients, the workflow focuses on the enhancement pattern (linear, band-like or nodular appearances) and the presence of concomitant intra-axial masses, directing the differential toward entities such as toxoplasmosis or lymphoma. For immunocompetent patients, the diagnostic pathway relies on clinical history and lesion characteristics to distinguish infectious, inflammatory, and neoplastic causes, further refined by the presence or absence of an intra-axial mass.

Conclusion: These diagnostic algorithms may help neuroradiologists structure the differential diagnosis and improve clinical decision-making.