AJNR. American journal of neuroradiology最新文献

Background and purpose: Endovascular therapy (EVT) has become the standard of care for selected patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). However, the impact of advanced age on EVT outcomes remains unclear. This study evaluated the safety, efficacy, and outcomes of EVT in elderly patients (≥85 years) compared to younger individuals in a real-world cohort.

Materials and methods: We conducted a retrospective analysis of the Stroke Research Consortium in Northern Bavaria (STAMINA) database, identifying 581 patients with occlusion in the anterior circulation who underwent EVT. Patients were stratified by age (≥85 years: n=95; <85 years: n=486). The primary outcome was functional recovery at 90 days, defined as a modified Rankin Scale (mRS) score ≤ pre-stroke mRS or pre-stroke mRS +1. Secondary outcomes included good functional outcome (mRS ≤2), mortality, successful EVT (TICI ≥ 2b), and symptomatic intracerebral hemorrhage (sICH).

Results: Elderly patients had a significantly higher 90-day mortality rate (53.8% vs 22.3%, p<0.001) and lower rates of good functional outcomes (1.1% vs. 27.0%, p<0.001). Functional recovery occurred in 13.7% of elderly patients compared to 21.0% in younger patients (p=0.14). Rates of sICH were similar (12.6% vs. 8.8%, p=0.34). Pre-stroke mRS was a significant predictor of good outcome in the elderly, with each one-point increase associated with a 56% decrease in the odds of achieving independence (OR 0.43, 95% CI 0.32-0.61; p<0.001).

Conclusion: EVT is technically feasible in elderly patients but associated with worse outcomes and higher mortality. Age alone should not exclude patients from EVT, though careful consideration of pre-stroke status is essential for individualized decision-making.

Background and purpose: Isolated congenital middle ear malformation (CMEM) contributes significantly to congenital hearing loss and growth problems. This study aims to compare 0.1-mm isotropic ultra-high-resolution CT (U-HRCT) and conventional high-resolution CT (HRCT) for assessing isolated CMEM, using surgical exploration as the standard.

Materials and methods: This single-center retrospective study included patients with surgically confirmed isolated CMEM who underwent U-HRCT or HRCT from January 2015 to April 2025. Middle ear abnormalities were identified based on operative outcomes and 4 subtypes were classified via the Teunissen standard. Two neuroradiologists blinded to surgical outcomes reviewed CT images for 10 subtle structural abnormalities and specific subtypes. The comparison of U-HRCT and HRCT in terms of interobserver and intraobserver agreement and detection of structural abnormalities and subtypes of CMEM were analyzed.

Results: The U-HRCT and HRCT groups included 61 patients (69 ears) and 37 patients (44 ears), respectively. U-HRCT exhibited significantly higher interobserver and intraobserver agreement and stronger concordance with surgical findings for all 10 abnormalities compared with HRCT. It also showed superior diagnostic sensitivity for CMEM (100.0% versus 90.9%; P = .013) and outperformed HRCT in differentiating clinical subtypes (0.774 versus 0.352; P<.001). U-HRCT achieved accuracies exceeding 0.85 in identifying all abnormalities and outperformed HRCT in detecting specific abnormalities including abnormal long process of the incus, lenticular process, abnormal stapes superstructure, stapes footplate fixation, and oval window atresia (P < .05).

Conclusions: Isotropic 0.1-mm U-HRCT significantly outperforms conventional HRCT in diagnosing CMEM, differencing subtypes, and detecting subtle abnormalities, supporting its clinical superiority for precise preoperative evaluation.

Background and purpose: Fetal ventriculomegaly (VM) is common and largely benign when isolated. However, it can occasionally progress to hydrocephalus, a more severe condition associated with increased mortality and neurodevelopmental delay that may require surgical postnatal intervention. Accurate differentiation between VM and hydrocephalus is essential but remains challenging, relying on subjective assessment and limited 2D measurements. Deep learning-based segmentation offers a promising solution for objective and reproducible volumetric analysis. This work presents an artificial intelligence-powered method for segmentation, volume quantification, and classification of the ventricles in fetal brain MRI to predict the need for postnatal intervention.

Materials and methods: This retrospective study included 222 patients with singleton pregnancies. An nnUNet was trained to segment the fetal ventricles on 20 manually segmented, institutional fetal brain MRIs combined with 80 studies from a publicly available data set. The validated model was then applied to 138 normal fetal brain MRIs to generate a normative reference range across a range of gestational ages (18-36 weeks). Finally, it was applied to 64 fetal brains with VM (14 of which required postnatal intervention). Receiver operating characteristic curves and area under curve (AUC) to predict VM and a need for postnatal intervention were calculated.

Results: The nnUNet predicted segmentation of the fetal ventricles in the reference data set were of high quality and accurate (median Dice score: 0.96; interquartile range: 0.93-0.99). A normative reference range of ventricular volumes across gestational ages was developed by using automated segmentation volumes. The optimal threshold for identifying VM was 2 SD from normal with a sensitivity of 92% and a specificity of 93% (AUC 0.97; 95% CI: 0.91-0.98). When normalized to intracranial volume, fetal ventricular volume was higher and subarachnoid volume lower among those who required postnatal intervention (P < .001, P = .003). The optimal threshold for identifying the need for postnatal intervention was 11 SD from normal, with a sensitivity of 86% and a specificity of 100% (AUC: 0.97; 95% CI: 0.86-1.00).

Conclusions: This work introduces a deep learning-based method for fast and accurate quantification of ventricular volumes in fetal brain MRI. A normative reference standard derived by using this method can predict VM and a need for postnatal CSF intervention. Increased ventricular volume is a strong predictor of postnatal intervention.

Background and purpose: Although high-resolution conebeam CT (HR-CBCT) is used for immediate evaluation of stent apposition, studies using this technique to evaluate flow diverter (FD) endothelialization during follow-up are limited. The study aims to investigate the potential of HR-CBCT in assessing FD endothelialization and identify factors influencing poor endothelialization.

Materials and methods: The clinical and imaging data of patients with unruptured intracranial aneurysms (UIAs) treated by FDs from March 2019 to October 2023 were retrospectively analyzed. HR-CBCT was used for immediate evaluation of stent apposition, and FD endothelialization at 3, 6, and 12 months postimplantation was evaluated by using HR-CBCT and digital subtraction angiography. Multivariate logistic regression analysis was used to identify factors associated with poor endothelialization.

Results: Among 402 FDs implanted for 446 aneurysms in 378 patients, 41 showed incomplete stent apposition (ISA) in postimplantation HR-CBCT scans. The aneurysm-occlusion rate at 12 months postimplantation was 84.8% (378/446), with 8.7% (35/402) of the FDs exhibiting in-stent stenosis (ISS). At 12 months postimplantation, 343 (85.1%) FDs showed good endothelialization, while 59 (14.9%) exhibited poor endothelialization. Multivariate logistic regression analysis identified age ≥60 years (OR = 2.209; 95% CI, 1.053-4.635; P = .04), a large aneurysm lumen inflow angle (OR = 1.102; 95% CI, 1.071-1.135; P < .001), parent artery excessive tortuosity (OR = 9.402; 95% CI, 1.141-77.479; P = .04), and ISA (OR = 10.967; 95% CI, 4.290-28.035; P < .001) as independent risk factors for poor endothelialization.

Conclusions: HR-CBCT can accurately evaluate FD endothelialization and ISS of UIAs after FD implantation. Age ≥60 years, a large aneurysm lumen inflow angle, parent artery excessive tortuosity, and ISA are independent risk factors for poor endothelialization.

Background and purpose: Brain imaging with MRI or CT is standard in screening for intracranial disease among ambulatory patients with cancer. Though MRI offers greater sensitivity, CT is frequently employed because of its accessibility, affordability, and faster acquisition time. However, the necessity of routinely performing a noncontrast CT with the contrast-enhanced study is unknown. This study evaluates the clinical and economic utility of the noncontrast portion of the brain CT examination.

Materials and methods: A board-certified neuroradiologist reviewed 737 brain CT reports from outpatients at The University of Texas MD Anderson Cancer Center who underwent contrast and noncontrast CT for cancer staging (October 2014 to March 2016) to assess if clinically meaningful findings were identified only on noncontrast CT. A Generative Pretrained Transformers-3 (GPT-3) model was then fine-tuned to extract reports with a high likelihood of unique and meaningful noncontrast findings from 1980 additional brain CT reports (January 2017 to April 2022). These reports were manually reviewed by 2 neuroradiologists, with adjudication by a third reviewer if needed. The incremental cost-effectiveness ratio of noncontrast CT inclusion was then calculated based on Medicare reimbursement and the 95% CI of the proportion of all reports in which noncontrast CT was necessary for identifying meaningful findings.

Results: Seven of 737 reports in the initial data set revealed meaningful findings unique to the noncontrast CT, all of which were hemorrhage. The GPT-3 model identified 145 additional reports with a high unique noncontrast CT finding likelihood for manual review from the second data set of 1980 reports. Nineteen of these reports were found to have unique and meaningful noncontrast CT findings. In total, 0.96% (95% CI: 0.63-1.40) of reports had meaningful findings identified only on noncontrast CT. The incremental cost-effectiveness ratio for the identification of a single meaningful finding on noncontrast CT missed on the contrast-enhanced study was $1855 to $4122.

Conclusions: In brain CT for ambulatory screening for intracranial disease in patients with cancer, noncontrast CT offers limited additional diagnostic value compared with contrast-enhanced CT alone. Considering the associated financial cost, workload, and patient radiation exposure associated with performing a noncontrast CT, contrast-enhanced brain CT alone is sufficient for cancer staging in patients with asymptomatic cancer.

Background and purpose: There is an imperfect correlation between morphologic MRI findings and radiating low back pain (LBP). Nerve irritation, visualized as glucose hypermetabolism on [¹⁸F]FDG-PET/MRI, has the potential to identify symptomatic segments. This study aimed to investigate the association of foraminal [¹⁸F]FDG uptake on PET/MRI, radiologic abnormalities, and patient outcomes.

Materials and methods: Prospectively recruited patients with radiating LBP underwent [¹⁸F]FDG-PET/MRI of the lumbar spine in this observational study. Back pain and leg/buttock pain were assessed by using the visual analog scale (0-10). Foraminal stenosis, facet joint arthropathy, and annular fissures of the disc were graded by radiologists. As part of the standard clinical care, a subset of patients received image-guided nerve root blocks, by using a steroid/anesthetic mixture, and pain on visual analog scale was noted before and after injection. Standardized tracer uptake was quantitatively assessed in all neural foramina, facet joints, and discs. Generalized estimating equations were used to investigate associations between the maximum standardized uptake value of [¹⁸F]FDG in the neural foramina, degree of stenosis (none, mild, moderate, severe), and pain, additionally adjusted for tracer uptake in the adjacent tissues, age, sex, and body mass index.

Results: A total of 110 lumbar neural foramina in 11 patients were included in the analysis. Generalized estimating equations revealed significant associations between foraminal [¹⁸F]FDG uptake and degree of foraminal stenosis (β = 0.18; 95% CI, 0.03-0.33; P = .02). In patients with unilateral radicular symptoms but bilateral stenoses on MRI, [¹⁸F]FDG uptake was significantly higher on the symptomatic side (1.64 versus 1.88; P = .002). In segments treated with image-guided nerve root block, change in pain was positively associated with foraminal [¹⁸F]FDG uptake before injection (β = 2.24; 95% CI, 0.03-4.45; P = .05) but negatively associated with degree of stenosis (β = -1.27; 95%CI -2.24 to -0.31; P = .01).

Conclusions: Foraminal [¹⁸F]FDG uptake on PET/MRI as a surrogate marker of nerve irritation may improve differentiation between painful versus nonpainful foraminal stenosis.

Background and purpose: This study aims to provide a comprehensive comparison of the performance and reproducibility of 2 commercially available artificial intelligence (AI) software computer-aided triage and notification solutions, Vendor A (Aidoc) and Vendor B (Viz.ai), for the detection of intracranial hemorrhage (ICH) on noncontrast-enhanced head CT scans performed within a single academic institution.

Materials and methods: The retrospective analysis was conducted on a large patient cohort from multiple health care settings within a single academic institution, utilizing standardized scanning protocols. Sensitivity, specificity, false-positive (FP), and false-negative (FN) rates were evaluated for both vendors. Outputs assessed included AI-generated case-level classification.

Results: Among 4081 scans, 595 were positive for ICH. Vendor A demonstrated a sensitivity of 94.4% and specificity of 97.4%, PPV of 77.7%, and NPV of 99.5%. Vendor B showed a sensitivity of 59.5% and specificity of 99.0%, PPV of 85.5%, and NPV of 96.2%. Vendor A had 20 FNs, which primarily involved subdural and intraparenchymal hemorrhages, and 97 FPs, which appear to be related to motion artifact. Vendor B had 145 FNs, largely comprising of subdural and subarachnoid hemorrhages, and 36 FPs, which appeared to be related to motion artifact and calcified or dense lesions. Concordantly, 18 cases were FNs and 11 cases were FPs for both AI solutions.

Conclusions: The findings of this study provide valuable information for clinicians and health care institutions considering the implementation of AI software for computer-aided triage and notification in the detection of intracranial hemorrhage. The discussion encompasses the implications of the results, the importance of evaluating AI findings in context-especially in the absence of explainability tools, potential areas for improvement, and the relevance of standardized scanning protocols in ensuring the reliability of AI-based diagnostic tools in clinical practice.

Background: Molecular imaging, particularly PET, has advanced the diagnosis and management of disease by visualizing biologic processes at a cellular and molecular level. PET imaging of the brain, spine, and head/neck, summarized under the umbrella term neuro-PET, enables noninvasive diagnosis and monitoring of diseases such as dementia, epilepsy, cancer, movement, or autoimmune disorders. The increasing prevalence of these conditions, as well as new treatment options necessitating response assessment, are expected to escalate neuro-PET imaging volumes, with projections for an increase in the need for specialized imaging services. This increasing clinical need highlights existing workforce shortages and underscores the need for neuroradiologists to acquire proficiency in molecular imaging. This expanded role seeks to address the growing demand. To this end, we propose a rigorous, structured, patient-centered, and collaborative framework for expanding neuroradiologists' training and practice to include neuro-PET interpretation.

Methods: This American Society of Neuroradiology consensus statement outlines competency recommendations, training pathways, and implementation strategies to incorporate neuro-PET into neuroradiology practice. This approach is based on existing guidelines and was informed by survey data from neuroradiologists and molecular imaging subspecialists revealing current practice patterns and training needs. For neuroradiology fellows, structured training encompasses hands-on neuro-PET imaging experience, understanding the biologic and molecular basis of radiopharmaceuticals used in neuro-PET, and integrating molecular insights with anatomic data. Neuroradiologists beyond fellowship can undertake practice-based curriculum involving supervised case interpretation, standardized reader training courses, continuing medical education (CME), and peer review.

Key message: Neuroradiologists, with their in-depth expertise of central nervous system structure and function, are well positioned to meld molecular imaging data with traditional anatomic findings. They can achieve competency and should be granted practice privileges in interpreting neuro-PET studies through a comprehensive combination of structured training, hands-on clinical experience, and documented CME hours.

Background and purpose: Spinal CSF leaks cause spontaneous intracranial hypotension (SIH), characterized by orthostatic headaches, but the detection of these leaks may require specialized and invasive spinal imaging. We have noted the presence of small lateral dural CSF collections of unclear significance on digital subtraction myelography (DSM) in some of these patients suspected of having SIH. The purpose of the present study was to compare radiographic and anatomic intraoperative findings in patients with such small lateral dural CSF collections who underwent surgical exploration.

Materials and methods: This retrospective cohort study included a consecutive group of patients suspected of having SIH who 1) did not have a spinal longitudinal extradural collection or CSF-venous fistula on spinal imaging; 2) underwent DSM under general anesthesia in the lateral decubitus position; and 3) underwent surgery for the finding of small lateral dural CSF collections of uncertain significance.

Results: The study group consisted of 27 patients (22 women and 5 men; mean age, 44.6 years; range, 16-72 years). DSM demonstrated a total of 31 small lateral dural CSF collections measuring 0.6-2.4 mm in diameter (mean, 1.3 mm) and 1.3-12.3 mm (mean, 3.5 mm) caudal to the origin of the neve root sleeve. Intraoperative exploration found evidence of a CSF leak in all 27 patients. One or more CSF-venous fistulas were found in 23 patients, and a pedicular type lateral CSF leak, in 4 patients. Radiographic differentiation between these 2 types of spinal CSF leaks could not be made with confidence.

Conclusions: Some patients suspected of having SIH have small lateral dural CSF collections on DSM caudal to the origin of the nerve root sleeve. We have found evidence of a CSF leak in all these patients on surgical exploration. This observation expands their treatment options.

Definitive treatment of spontaneous intracranial hypotension caused by a spinal CSF leak may be challenging with conservative management or an epidural blood patch. This study describes 2 cases of spontaneous intracranial hypotension treated with fluoroscopically-guided, catheter-delivered Onyx to seal a spinal CSF leak, with significant improvement observed during a 2-year follow-up. Digital subtraction myelography was used to localize the site of the CSF leak. Onyx was precisely delivered to the site of the CSF leak via a catheter under fluoroscopic guidance. Postprocedural spinal CT confirmed the presence of Onyx at the injected site. Both patients exhibited resolution of symptoms and CSF leaks during the 2-year follow-up. Repeat spinal MRI demonstrated a gradual and marked reduction in the spinal longitudinal epidural collection during the follow-up period. No noticeable complications were reported. These findings indicate that epidural Onyx treatment may represent a novel and promising strategy for managing spontaneous intracranial hypotension caused by a dural tear.