AJNR. American journal of neuroradiology最新文献

Background: Intracranially extending temporomandibular joint (TMJ) lesions may be radiologically misinterpreted as primary intracranial or skull base pathologies, leading to diagnostic delays or inappropriate management.

Purpose: This systematic review aimed to characterize the clinical and imaging features of such TMJ lesions and evaluate the impact of radiologic misclassification. We also aimed to develop a diagnostic framework for when to consider an intracranially extending TMJ lesion, based on clinical and radiologic features.

Data sources: A comprehensive search of MEDLINE, Scopus, and EMBASE, conducted in accordance with PRISMA guidelines, yielded 2255 records.

Study selection: After screening with predetermined inclusion and exclusion criteria, 128 studies involving 152 patients were included in the final analysis.

Data analysis: Statistical analyses were performed using STATA software. We also identified 3 patient cases through our institutional neuroradiology practice who were clinically and radiologically assessed for intracranially extending TMJ lesions.

Data synthesis: Patients had symptoms for an average of 34 months before diagnosis (47% women, mean age 50 years). The most common pathologies were pigmented villonodular synovitis/tenosynovial giant-cell tumor (43%) and synovial chondromatosis (24%). Neurologic symptoms were reported in 48% of cases, most frequently hearing loss (70%). Nearly one-third (33%) of cases with an imaging differential did not list a TMJ pathology (18/55). In cases with accurate imaging diagnosis, 90% had both CT and MRI performed. Most lesions were nonenhancing (CT 83%, MRI 75%) and demonstrated no adjacent brain edema (96%). In 2 cases, a TMJ ganglion cyst and pseudogout were misdiagnosed as intracranial tumors, resulting in unnecessary intervention, including repeat craniotomy and radiotherapy.

Limitations: There were inherent biases of case report literature, including variability in the reporting of the imaging and clinical features, management, and follow-up.

Conclusions: TMJ lesions with intracranial extension often present with nonspecific symptoms and can mimic extra-axial tumors, leading to misdiagnosis on imaging. Recognition of hallmark imaging features, including lack of parenchymal invasion and distinct imaging patterns, may help improve radiologic accuracy and prevent overtreatment. We propose a diagnostic framework outlining when to suspect intracranially extending TMJ lesions based on clinical and imaging features, and how to avoid common diagnostic pitfalls.

Background: Bibliometric profiling of specialty journals can provide insight into scientific trends, collaboration patterns, and the evolving focus of fields. We analyzed three decades of American Journal of Neuroradiology (AJNR) publications (1995-2024) to determine whether longitudinal bibliometric indicators of AJNR publications demonstrate measurable temporal trends and reflect changes in citation behavior, journal impact, and article characteristics over time.

Materials and methods: Materials and Methods: All AJNR publications within the study period were retrieved and standardized. Title-based mining of curated keywords described annual frequencies, temporal dynamics, and exploratory correlation patterns. We performed a descriptive bibliometric ranking analysis and assessed authorship via total and first-author counts. Collaboration patterns were evaluated using descriptive co-authorship network statistics including degree, clustering coefficient, and centrality measures.

Results: AJNR persistently remain in the first quartile for "Neurology (Clinical)" and "Radiology, Nuclear Medicine and Imaging" during the entire analyzed period. Publication volume exhibited long-cycle fluctuations, with a plateau in the mid-2000s and a modest decline after 2020. Cerebrovascular topics dominated title keywords, with temporal surges closely aligning with major trials and the uptake of mechanical thrombectomy. Keyword associations analysis demonstrated tight clustering of vascular and interventional items. Authorship distribution was highly skewed, with a small group of prolific contributors a large number of occasional authors, while international participation expanded over time. Co-authorship networks were dense and highly clustered, consistent with mature multi-institutional collaboration.

Conclusions: AJNR's bibliometric profile reflects the maturation of diagnostic and interventional neuroradiology, with topic surges tracking pivotal clinical evidence and technological adoption. Despite the concentration of output among a limited prolific groups, collaboration density and global engagement have increased steadily.

Facial nerve palsy is a debilitating condition with substantial physical and psychosocial impacts. Facial reanimation encompasses surgical reconstructive procedures aimed at restoring the functions of the facial nerve to improve function and quality of life in patients with facial palsy. This educational review outlines the essential principles for interpreting imaging studies for facial reanimation including fundamental anatomy, technical descriptions and imaging appearances of common reconstructive procedures, and key findings that should be included when reporting studies for patients being considered for facial reanimation. The information provided in this review equips radiologists to contribute effectively to a multidisciplinary team necessary for the treatment of patients with facial nerve palsy.

Background: Venous anatomical variants are common and generally considered normal. However, growing recognition of cerebral venous disorders (CVD) in neurological disease has prompted renewed interest in venous architecture, especially with increasing use of the internal jugular vein (IJV) as a target for outflow augmentation. Establishing baseline data on venous stenosis prevalence in an unselected population is critical for future research. This study aimed to assess the prevalence of IJV stenoses in patients undergoing neck CT angiography for unrelated indications.

Methods: We conducted a multicenter, retrospective study analyzing the venous anatomy of patients who underwent CT angiography for unrelated conditions, primarily large vessel occlusion. Stenosis was graded based on the percentage of lumen narrowing with a NASCET-style methodology, and the relationship between IJV stenosis severity and suboccipital collateral drainage was evaluated. Consecutive CT angiograms of patient were queried to map anatomical features.

Results: 68% of the 679 total patients exhibited some degree of IJV stenosis. Severe unilateral stenosis (≥51%) was present in approximately 21% of patients, while complete or near-complete occlusion was uncommon at 8%. Bilateral high-grade stenosis was noted in 18% of patients for >50% stenosis and in only 2% of patients for >75% stenosis. A greater degree of stenosis correlated with increased suboccipital collateral vein diameter (p = 0.0025).

Conclusion: IJV stenosis is common on CT angiography performed for non-venous indications with a correlation between the degree of stenosis and suboccipital collateral vein diameter. The clinical significance of these findings and its possible contribution to CVD requires further prospective investigation.

Background and purpose: The sphenoid bone forms from multiple ossification centers. Its body develops through the fusion of presphenoid and postsphenoid cartilages separated by the intersphenoid synchondrosis. Variations in ossification can lead to persistent craniopharyngeal duct remnants, potentially associated with pituitary dysfunction or tumors. We aimed to determine the timeline of closure of these synchondroses and associated foramina in children without skull base abnormalities on CT scans.

Materials and methods: This retrospective study analyzed CT scans of children aged 0-6 years from a tertiary pediatric hospital (2018-2022). Scans with abnormalities or skull anomalies were excluded. Two pediatric radiologists assessed synchondroses and foramina, classifying them as patent or fused. Sample size was determined using area under the curve (AUC) analysis. Statistical methods included descriptive analysis, interrater reliability (Cohen κ, intraclass correlation coefficient), Mann-Whitney U test, and cut-point analysis with bootstrapping to determine closure times.

Results: We analyzed 160 scans (94 boys, 58.8%; 66 girls, 41.2%) with a median age of 1.4 years (interquartile range: 0.3-3.7). Interrater reliability was strong (κ > 0.80) for most structures, moderate for detecting intrapresphenoid synchondrosis and pneumatization, and weak for intrapostsphenoid synchondrosis. Cut-point analysis demonstrated that the intersphenoid synchondrosis fused first at 4 months, followed by the intrapresphenoid synchondrosis, the anterior and posterior foramen, with pneumatization occurring last at 24.8 months; all with an AUC >80%. Pair-wise threshold differentiation showed pneumatization followed the closure of intersphenoid synchondrosis, intrapresphenoid synchondrosis, and anterior foramen by 22.8, 22.7, and 17.4 weeks, respectively.

Conclusions: The sphenoid body synchondroses and foramina show a predictable closure timeline within the first year of life, while pneumatization commences after the second year. Understanding this timeline provides radiologists with a reference standard for interpreting CT examinations that include the skull base (eg, head, maxillofacial, temporal bone CTs) in children younger than 2 years of age, supporting more confident interpretation and potentially reducing overcalling and related follow-up imaging.

The cerebellum has garnered increasing interest as a promising deep brain stimulation (DBS) target for dyskinetic cerebral palsy and other conditions such as cerebellar ataxia and stroke. Functional MRI of cerebellar stimulation can facilitate more comprehensive understanding of the mechanisms underlying symptom response; however, evidence regarding its safety and feasibility is lacking. In this report, we first assessed the risk of radiofrequency-induced heating through simulations informed by postoperative CT images from three patients with distinct cerebellar DBS hardware orientations. Following heating estimates, and as part of an ongoing trial (NCT06122675), we then collected three functional MRI runs in one anesthetized patient with DBS turned ON, turned OFF, and cycled ON/OFF in 30s intervals. Simulations suggested acceptable heating under our scanner and sequence conditions, with peak temperature increases ranging from 0.6-1.5°C. Preliminary stimulation-induced brain activations and functional connectivity changes appeared consistent with the underlying structural anatomy.

Background: Alternative work schedules can be desirable for trainees and provide more flexibility for service coverage needs. Continued evaluation is needed to ensure educational objectives are met and that the intended wellness components are fulfilled. Creativity and compromise are essential for balance between education, staffing, and personal needs.

Methods: We conducted a retrospective review (July 2022-January 2026) of a pilot Sunday-Thursday "shifted week" neuroradiology rotation. Resident perception was evaluated through pre- and post-implementation surveys and end-of-rotation evaluations. Productivity was measured using daily case volume and work relative value units. Performance outcomes included Diagnostic Radiology In-Training Examination neuroradiology scores and report turnaround times.

Key message: Shifting a Neuroradiology resident service week to a Sunday-Thursday schedule met the educational experience, staffing, and contrast coverage needs while reducing the overall call frequency for residents. Residents reported high satisfaction with the shifted rotation, with most endorsing improved educational value and stable or improved quality of life. Faculty supervision, turnaround times, and actionable result communication were maintained at levels comparable to traditional schedules.

Background and purpose: Radiofrequency ablation (RFA) has emerged as an effective nonsurgical treatment for symptomatic benign thyroid nodules and toxic adenomas. While post-RFA ultrasonographic changes are expected, they may inadvertently evoke alarm and prompt unnecessary interventions when risk stratification models such as the American College of Radiology Thyroid Imaging Reporting & Data System (ACR TI-RADS) are applied. This study aims to quantify ultrasound imaging changes of thyroid nodules using TI-RADS scoring before and after RFA and highlights that these changes should not be used as a basis for clinical action.

Materials and methods: This retrospective study analyzed patients who underwent RFA for symptomatic thyroid nodules at a quaternary care academic medical center between May 2021 and May 2024. All nodules were assessed using the ACR TI-RADS calculator and underwent fine-needle aspiration (FNA) biopsy before treatment. Following RFA, ultrasonography was conducted at 3-month intervals, and TI-RADS scores were reassessed. The primary end point was the change in TI-RADS classification following RFA.

Results: A total of 28 nodules from 25 patients were monitored after RFA for a median follow-up duration of 419 days. Most (92.9%) were benign (Bethesda II) on FNA. The mean volume reduction ratio (VRR) was 66.7% (range 33.0% to 91.6%), with therapeutic success (VRR >50%) achieved in 86% of patients. Post-RFA risk stratification increased following RFA, with the mean TI-RADS score increasing from 3.04 to 4.25 (P < .001), predominantly driven by increased hypoechogenicity and new echogenic foci/calcifications.

Conclusions: Thyroid nodules frequently undergo post-RFA structural changes that result in misleading upstaging on the ACR TI-RADS stratification system. These changes are expected and require cautious interpretation to avoid overdiagnosis, patient anxiety, and mismanagement.

Background and purpose: Tranexamic acid (TXA) may reduce the progression of vasogenic edema in traumatic brain injury (TBI), potentially providing a survival benefit in specific patients. This study evaluates a CT-based quantitative imaging tool for identifying patients with acute TBI who may benefit from prehospital TXA.

Materials and methods: This is a post hoc analysis of the Prehospital Tranexamic Acid Use for Traumatic Brain Injury trial, a multicenter, placebo-controlled trial that randomized patients with moderate or severe TBI to either a 1-g TXA bolus followed by 1-g infusion, a 2-g TXA bolus, or a placebo. CT images were analyzed using a novel Matlab-based algorithm to calculate the percentage of voxels within various density ranges. The region of interest was defined as the entire brain parenchyma after skull removal. The 10-20 HU range, identified as most representative of vasogenic edema based on correlation with mean ADC values in a subset of 102 patients, was used for further analysis. Logistic regression was performed to evaluate the relationship between voxel percentages in the 10-20 HU range and in-hospital mortality. Threshold analysis identified the minimum voxel percentage within the 10-20 HU range associated with significant TXA survival benefit. Relative risk reduction in mortality was calculated for patients above and below this threshold.

Results: In a cohort of 550 patients, logistic regression showed that the association between TXA use and in-hospital survival varied with the percentage of brain voxels in the 10-20 HU range (interaction P = .04). Threshold analysis identified a cutoff of 3% of brain parenchymal voxels in the 10-20 HU range, corresponding to approximately 40 mL of vasogenic edema, beyond which TXA administration was associated with a significant survival benefit (P = .04). In this subgroup, TXA was associated with a relative risk of mortality of 0.41 (95% CI, 0.17-0.99) compared with a placebo.

Conclusions: A voxel percentage of ≥3% within the 10-20 HU CT density range serves as a promising imaging biomarker associated with a survival benefit from TXA in patients with acute TBI in the prehospital setting. Prospective validation is required to confirm these findings before integrating this biomarker into clinical decision-making for personalized TBI management.

MRI technology has continuously advanced since its inception in the 1980s, yet access to MRI remains restricted due to its high cost and traditionally long acquisition times. This article reviews access-oriented strategies for expanding MRI availability in neuroradiology, focusing on (1) workflow efficiency enabled by accelerated and artificial intelligence-assisted imaging, (2) targeted MRI protocols designed to answer specific clinical questions, and (3) emerging low-field and portable MRI technologies for resource-constrained and point-of-care settings. We provide practical trade-offs, limitations, and use case-driven frameworks to inform real-world implementation. Examples of how these technologies are utilized in neuroradiology are provided along with perspectives on the advantages and disadvantages of each approach. This article portrays current accessibility issues and paves the way toward an improved understanding of the opportunities and future of expanded MRI access.