AJNR. American journal of neuroradiology最新文献

Purpose: To evaluate the feasibility and technical performance of integrating a Delay Alternating with Nutation for Tailored Excitation (DANTE) preparation into a deep learning-accelerated, post-contrast T1-SPACE sequence for intracranial vessel wall imaging (IC-VWI).

Materials and methods: In this retrospective, single-center study, 35 patients (22 women; mean age, 57.9 ± 17.1 years) underwent IC-VWI using post-contrast DL-T1-SPACE with (T1-SPACE_DL+DANTE) and without (T1-SPACE_DL) a DANTE preparation. Two neuroradiologists independently scored lumen and wall visualization across the arterial segments on a 4-point Likert scale (1: worst to 4: best) and graded venous flow artifacts along the middle cerebral artery (MCA), peri-mesencephalic veins (PMV), deep cerebral veins (DCV), and cortical veins (CV). Intersequence comparisons used cumulative-link mixed-effects models (CLMMs); segments were additionally pooled and analyzed as proximal versus distal. Venous flow artifact scores were compared with paired Wilcoxon tests between sequences and percentage agreement between readers. Exploratory Bland-Altman analysis was also performed for both readers.

Results: A total of 556 vessel-segment pairs were analyzed. In CLMM analysis, T1-SPACE_DL+DANTE improved lumen scores versus T1-SPACE_DL (pooled OR 40.02; 95% CI 24.06-66.57; FDR p<0.001) but reduced wall scores (pooled OR 0.11; 95% CI 0.08-0.14; FDR p<0.001). By anatomic group, lumen ORs were 26.03 (proximal) and 91.93 (distal), and wall ORs were 0.12 (proximal) and 0.04 (distal) (all FDR p<0.001). Venous flow artifacts improved across all analyzed subsites (p<0.001). ±1-point inter-reader concordance was near perfect across analyses. Bland-Altman plots showed negative lumen bias (favoring T1-SPACE_DL+DANTE) and positive wall bias (favoring T1-SPACE_DL) without consistent proportional bias.

Conclusion: Adding DANTE preparation to deep-learning accelerated IC-VWI was associated with fewer flow-related artifacts and a clearer depiction of the vessel lumen, which may support a more accurate assessment of intracranial vasculopathies and aneurysms. Potential gains were accompanied by a modest wall-visualization penalty, which is not unexpected with a flow-suppression pulse.

Skull base biopsies are technically challenging due to complex anatomy and proximity to vital structures. Traditional transcervical and transoral approaches offer limited access to the clivus and risk poor depth perception and complications. Although transnasal techniques have improved access, X-ray-guided methods are rarely reported. We describe the first transnasal X-ray-guided clival biopsy in a middle-aged patient with suspected skull base osteomyelitis. Preoperative CT, MRI, and PET-CT enabled precise targeting and safe trajectory planning. In a biplane angiographic suite, a guidewire was advanced transnasally, and a 9F introducer sheath was positioned against the anterior clivus. An 11G bone needle was then advanced under fluoroscopy and cone-beam CT into the lesion. Tissue sampling was successful and complication-free, confirming Staphylococcus haemolyticus osteomyelitis, which resolved with targeted antibiotics. This minimally invasive technique offers accurate access to superior clival lesions and may broaden options for selected skull base biopsy cases.

Background and purpose: T1-weighted hypointense lesions resulting from MS reflect chronic, irreversible tissue injury mediated by autoimmune inflammation and are associated with neurologic disability. The evolution of such lesions is heterogeneous in the presence or absence of disease-modifying therapy (DMT). We investigated dynamic changes of T1-weighted hypointense lesions along with total T1-weighted hypointense lesion volumes to further understand MRI features that may reflect clinically silent disease activity.

Materials and methods: A retrospective study was performed involving people with MS with 3 consecutive standardized MRI time points within a single academic center. Individuals with formal neuroradiology interpretations lacking evidence of T1-weighted hypointense lesion change were included. Approximately 8-12 nongadolinium-enhancing T1-weighted hypointense lesions measuring at least 3 mm² were selected from a 3D MPRAGE from each individual. Total T1-weighted hypointense lesion volumes were also quantified at each time point. The Lambda, Mu, and Sigma method was used to estimate the SD of the annualized volume rate of change as a function of the lesion volume at the prior time point. The longitudinal associations between treatment class on T1-weighted hypointense lesion dynamics and relationship to patient- or physician-reported disease worsening, acute clinical relapse, and MRI advancement were evaluated.

Results: The cohort comprised 91 people (71.4% women; mean disease duration of 9.32 years; SD: 7.22 years) who were primarily white (80.2%). Of treated individuals, most were exposed to non-high-efficacy DMTs at least once (48.4%). In total, 273 MRI studies yielding 790 T1-weighted hypointensities were studied longitudinally. Predominantly enlarging T1-weighted hypointense lesions were seen in 82.4% of individuals over 3 MRI time points. The odds of overall T1-weighted lesion volume contraction did not differ between those on high-efficacy treatment (P = .71) or those untreated (P = .85), compared with non-high-efficacy agents. Treatment group did not influence total change in T1-weighted hypointense lesion volumes, and correlations with clinical or MRI outcomes were not observed.

Conclusions: Current DMT classifications may have minimal influence on T1-weighted hypointense outcomes, highlighting the need for treatments that directly target ongoing tissue injury.

Background and purpose: Stent-assisted coiling (SAC) is widely used for the treatment of wide-neck, unruptured intracranial aneurysms. However, direct comparative data between different stent platforms remain limited. This study aimed to evaluate the safety and efficacy of the Low-profile Visualized Intraluminal Support (LVIS) stent versus the Neuroform Atlas stent in the treatment of unruptured ICA aneurysms measuring <10 mm in diameter.

Materials and methods: A retrospective analysis was performed on 287 unruptured ICA aneurysms (<10 mm) in 247 patients treated with SAC using either the LVIS or Neuroform Atlas stent across 3 affiliated institutions between March 2017 and December 2023. Patients were divided into 2 groups: group A (Neuroform Atlas) and group L (LVIS). After 1:1 propensity score matching for demographic, clinical, anatomic, and procedural variables, key outcomes including Raymond class 1 occlusion, volume embolization ratio, and periprocedural complications were compared between the 2 groups.

Results: Among the 287 aneurysms, 237 (82.6%) were treated with the Neuroform Atlas stent and 50 (17.4%) with the LVIS stent. Propensity score matching yielded 46 matched pairs. Immediately after treatment, group L demonstrated significantly higher rates of complete occlusion and a greater volume embolization ratio compared with group A (P = .022 and .004, respectively). At the 1-year follow-up, the complete occlusion rate remained significantly higher in group L than in group A (52% versus 24%; P = .007). The incidence of ischemic and hemorrhagic complications did not differ significantly between the 2 groups.

Conclusions: For unruptured ICA aneurysms <10 mm in diameter, SAC using the LVIS stent was associated with a significantly higher rate of complete occlusion at 1 year compared with the Neuroform Atlas stent, without an increase in periprocedural complications. These results support the safety and efficacy of the LVIS stent in achieving favorable long-term angiographic outcomes in small- to medium-sized unruptured ICA aneurysms.

Background and purpose: Gadolinium-based contrast agents (GBCAs) are essential in pediatric neuroimaging, enabling visualization of pathology that disrupts the blood-brain barrier. Gadopiclenol is a new macrocyclic GBCA with higher T1 relaxivity, permitting a 50% dose reduction while maintaining diagnostic quality. However, it is unknown whether this higher relaxivity alters background extra-axial vascular enhancement. We hypothesized that gadopiclenol, despite its lower dose, would increase background enhancement on postcontrast pediatric brain MRI compared with gadoterate meglumine (Gd-DOTA).

Materials and methods: In this retrospective observational study, 302 contrast-enhanced brain MRI studies in patients aged 2-18 years were reviewed: 151 with gadopiclenol (0.05 mmol/kg) and 151 with Gd-DOTA (0.1 mmol/kg). Postcontrast sequences included 3D T1 spin-echo (SE), 3D T1 spoiled gradient-echo (SPGR), 2D T1 TSE, and 2D FLAIR. Two neuroradiologists established binary enhancement categories based on sulcal enhancement thresholds (high versus low). One reader assigned scores for all studies; a second reader evaluated a subset for interobserver agreement. Logistic regression assessed the association between contrast agent and high enhancement, adjusting for age, sex, anesthesia, and scanner field strength.

Results: Gadopiclenol was independently associated with significantly greater odds of high extra-axial enhancement on all T1-weighted sequences: 3D T1 SE (OR = 10.2; P < .001), 3D T1 SPGR (OR = 10.7; P < .001), and 2D T1 TSE (OR = 14.0; P < .001). Anesthesia was also an independent predictor of high enhancement on 3D SE and SPGR. On 2D FLAIR, contrast agent had no effect; instead, younger age was associated with high enhancement (P = .022), with an age-anesthesia interaction suggesting attenuation of this effect under sedation. Interobserver agreement was moderate to substantial (κ = 0.530-0.632).

Conclusions: Gadopiclenol increases background extra-axial enhancement on T1-weighted postcontrast sequences in pediatric brain MRI, likely reflecting its higher relaxivity. Radiologists should be aware of this effect to avoid misinterpretation as leptomeningeal pathology. Postcontrast FLAIR remains unaffected and continues to serve as a reliable sequence for detecting true meningeal disease.

CSF-venous fistulas are a common cause of spontaneous intracranial hypotension. Most CSF-venous fistulas occur in the thoracic spine, and recently described myelographic techniques have been primarily tailored to localize fistulas in this location.^1-4 However, a small subset of CSF-venous fistulas can occur at the superior or inferior ends of the spine, ranging from the skull base to the sacrum. In this Video Article, we discuss modifications to decubitus myelography needed to safely and confidently diagnose CSF-venous fistulas at the extremes of the spine, including the skull base and sacrum.^5-7 We also show unique case examples of these relatively uncommon leaks, which were found using decubitus digital subtraction or CT myelography with simple technical modifications.

Background and purpose: In the context of brain tumor characterization, we focused on two key questions which, to the best of our knowledge, have not been explored so far: (a) stability of radiomics features to variability in multi-regional segmentation masks obtained with fully-automatic deep segmentation methods and (b) subsequent impact on predictive performance on downstream prediction tasks. The hypothesis is that highly stable and discriminatory radiomics features lead to generalizable radiogenomics models in brain tumor characterization.

Materials and methods: We used the publicly available BraTS 2020 dataset for tumor segmentation and IDH prediction. For segmentation, the training cohort included 369 subjects with preoperative multiparametric 3D MRI (T1, T1-Gd, T2, and FLAIR) and manual annotations of tumor subregions (whole tumor, WT; tumor core, TC; enhancing core, EC), while the validation cohort comprised 125 subjects with imaging data only. For IDH prediction, the discovery dataset consisted of 148 subjects (57 IDH-mutant, 91 IDH-wildtype) and the testing dataset included 70 subjects (32 IDH-mutant, 38 IDH-wildtype). Seven state-of-the-art CNNs were used for fully automatic multi-regional tumor segmentation. Radiomics feature stability across segmentation models was assessed using the overall concordance correlation coefficient (OCCC), and discriminatory features were selected with recursive feature elimination with support vector machines (RFE-SVM). Predictive performance was evaluated using AUC, and model stability was quantified by the relative standard deviation (RSD) of AUC.

Results: Our study found that highly stable radiomics features were predominantly texture-based (79.1%), mainly extracted from the whole tumor (WT) region (96.1%), and largely derived from T1-Gd (35.9%) and T1 (28.0%) sequences. Mean feature stability (OCCC) was highest for WT (0.87 ± 0.12), followed by TC (0.76 ± 0.13), EC (0.72 ± 0.13), and shape features (0.72 ± 0.11), with shape and EC features showing the lowest stability. Stability filtering reduced non-physiological variability, as reflected by a lower RSD (2.28% vs. 0.64%), and significantly improved predictive performance across eight segmentation schemes (AUC: 0.81 ± 0.02 vs. 0.94 ± 0.006).

Conclusion: Robust and generalizable radiogenomics models can be learned with highly stable and discriminatory radiomics features.

Background: Inequities in neuroimaging access represent a major barrier to timely diagnosis and treatment of neurologic disease, particularly in low- and middle-income countries. This article examines factors contributing to neuroimaging access challenges in low- and middle-income countries and discusses practical, sustainable strategies to improve equity in global neuroimaging capacity.

Methods: This State of Practice was developed by the members of the American Society of Neuroradiology's Diversity and Inclusion Committee, who reviewed published literature, global radiology workforce data, and Accreditation Council for Graduate Medical Education training statistics. The committee members also integrated insights from outreach experiences and collaborations with professional organizations working to improve global health.

Key message: Bridging neuroimaging disparities requires coordinated action that integrates technological innovation, workforce development, and long-term collaboration. Expanding the use of portable and low-cost imaging systems, global teleradiology, and artificial intelligence alongside education, outreach, and policy engagement can help build capacity and improve access. Sustained partnerships between high- and low-resource regions are essential to achieving a more equitable and globally connected neuroradiology community with the potential to improve health outcomes worldwide.

Background and purpose: Cranial nerve palsy (CNP) is a significant manifestation of cavernous sinus dural arteriovenous fistulas (CSDAVFs), but factors influencing its occurrence, aggravation, and resolution remain unclear. This study aimed to identify clinical and angiographic variables associated with CNP in patients with CSDAVF undergoing endovascular treatment (EVT).

Materials and methods: We retrospectively reviewed 196 patients treated for CSDAVF at a tertiary hospital between October 1991 and March 2023. Patient demographics, clinical presentation, imaging findings, treatment specifics, and outcomes were analyzed to identify factors associated with CNP at presentation, aggravation after EVT, and resolution during follow-up.

Results: Among the 196 patients (mean age, 59.3 ± 11.6 years; 23.5% men), 73.0% presented with CNP. The proliferative type (OR: 2.82; 95% CI: 1.26-6.29; P = .01) and contralateral feeders (OR: 2.53; 95% CI: 1.17-5.46; P = .02) were significantly associated with initial CNP. Aggravation of CNP occurred in 8.7% of cases, primarily associated with diffuse coil packing (P = .01) and specific coil packing locations in the cavernous sinus (superolateral for third CNP, P =.01; posterolateral for sixth CNP, P < .001). Complete resolution of CNP was achieved in 84% of patients, with hypertension (hazard ratios [HR]: 0.55; 95% CI: 0.35-0.87; P = .01), initial gross extraocular movement limitation (HR: 0.53; 95% CI: 0.35-0.81; P = .003), retreatment (HR: 0.50; 95% CI: 0.28-0.90; P = .02), and orbital pattern (HR: 1.70; 95% CI: 1.03-2.81; P = .04) identified as significant predictors.

Conclusions: Proliferative fistula type and contralateral feeders were associated with initial CNP in CSDAVFs, while coil packing location significantly influenced posttreatment aggravation. Complete CNP resolution was achieved in most patients, though factors such as hypertension, severe initial symptoms, and retreatment negatively affected recovery. These findings highlight key clinical and angiographic variables critical for guiding treatment strategies and predicting outcomes in patients with CSDAVF.