AJNR. American journal of neuroradiology最新文献

{"title":"ASFNR Clinical State of Practice Statement on Imaging of Chronic Subdural Hematoma.","authors":"Sabha Ahmed, Muhammed Amir Essibayi, Jay Kakadiya, Vidhi Dhaduk, Huanwen Alvin Chen, Marco Colasurdo, Ankit Arora, Rajan Jain, Gaurang Shah, David Altschul, Behroze A Vachha, Dylan Wolman, Ferdinand Hui, Nicholas Brandmeir, Lea Alhilali, Girish Bathla, Ajay Malhotra, Uttam K Bodanapally, Dheeraj Gandhi, Vivek S Yedavalli, Dhairya A Lakhani","doi":"10.3174/ajnr.A9690","DOIUrl":"https://doi.org/10.3174/ajnr.A9690","url":null,"abstract":"<p><strong>Background: </strong>The efficacy of middle meningeal artery embolization (MMAE) for chronic subdural hematoma (cSDH) has heightened interest in imaging biomarkers that may reflect neomembrane activity, predict recurrence, and identify patients most likely to benefit from treatment. Characterization of hematoma internal architecture, referred to as the imaging phenotype, may provide indirect information regarding the biological activity and maturation of the neomembrane. However, imaging phenotype has not been incorporated into randomized trials or validated treatment-selection algorithms, and standardized definitions and reporting remain lacking.</p><p><strong>Methods: </strong>The American Society of Functional Neuroradiology Clinical Practice Committee developed this State of Practice statement through expert consensus and review of the available literature.</p><p><strong>Key message: </strong>Noncontrast CT (NCCT) remains the primary imaging modality for cSDH assessment. Hematoma burden should be characterized by maximum thickness measured perpendicular to the inner table, midline shift, and, when appropriate, volume. Volume may be estimated using the ABC/2 formula, whereas segmentation is more accurate for irregular, crescentic, or multiloculated collections when available. Internal architecture should be described using the Nakaguchi framework of homogeneous, laminar, separated, and trabecular phenotypes, with mixed or transitional features explicitly reported. Advanced techniques, including dual-energy CT, photon-counting CT, MRI, and arterial spin labeling, may provide information regarding membrane activity but are supported by limited, largely single-center evidence and currently have a problem-solving rather than routine role. Standardized reporting and prospective validation are needed before imaging phenotype or advanced-imaging biomarkers can guide treatment selection.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149229525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The unknown face of Sturge-Weber Syndrome type 3 - a hybrid scoping review of the literature.","authors":"Roger Smyth, George Wang, Adam Kenji Yamamoto, Kshitij Mankad, Rahul Lakshmanan, Peter Shipman, Michael Mason, Richard R Warne","doi":"10.3174/ajnr.A9687","DOIUrl":"https://doi.org/10.3174/ajnr.A9687","url":null,"abstract":"<p><p>Sturge-Weber syndrome (SWS) type 3 is a rare neurocutaneous disorder characterised by isolated leptomeningeal angiomatosis without facial capillary malformation or ocular involvement. Existing literature is limited to case reports and small series, resulting in incomplete characterisation of its clinical and radiological phenotype and frequent diagnostic delay. The increased prevalence of contrast-enhanced MRI has improved detection of pial angiomatosis and associated parenchymal abnormalities. This scoping review aimed to map the available evidence and define current knowledge gaps. Our aim is to synthesise published data on SWS type 3, describe demographic, clinical, and imaging features, and contribute a 15-patient institutional cohort.PubMed and EMBASE were systematically searched (31 March-4 April 2025), with additional studies identified through reference screening. Eligible studies reported isolated leptomeningeal angiomatosis without port-wine birthmark and included contrast-enhanced MRI. Seventy-five published cases were identified. Heterogeneity in study design and reporting precluded quantitative pooling; data were synthesised descriptively. SWS type 3 demonstrates a consistent pattern of unilateral, predominantly occipitoparietal leptomeningeal angiomatosis, most commonly presenting with focal-onset seizures. Despite improved MRI-based recognition, substantial gaps remain regarding natural history, pathophysiology, and optimal management. Prospective, standardised studies are required to refine diagnostic criteria and guide evidence-based care.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149225449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-intensity focused ultrasound for neuromodulation: neuroimaging and neurointerventional perspectives.","authors":"John Coetzee, Masataka Wada, Byung C Yoon","doi":"10.3174/ajnr.A9683","DOIUrl":"https://doi.org/10.3174/ajnr.A9683","url":null,"abstract":"<p><p>Low-intensity focused ultrasound (LIFU) is an emerging, noninvasive neuromodulation technique with a growing evidence base and set of applications. LIFU uses low-energy acoustic waves that are focused to a focal volume in the millimeter range and transiently modulate neuronal activity in targeted cortical and subcortical brain structures. Unlike high-intensity focused ultrasound (HIFU), which is designed to cause thermal ablation of the target tissue, LIFU is intended to modulate neuronal activity rather than ablate tissue. In this article, we review the technical background, clinical applications, and safety of LIFU from neuroimaging and neurointerventional perspectives.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149225457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The importance of CSF distribution for target values and risk profiling for idiopathic Normal Pressure Hydrocephalus shunt surgery.","authors":"Marcel Warntjes, Charalampos Georgiopoulos, Nikolaos Saridakis, Rafael Holmgren","doi":"10.3174/ajnr.A9682","DOIUrl":"https://doi.org/10.3174/ajnr.A9682","url":null,"abstract":"<p><strong>Background and purpose: </strong>Idiopathic Normal Pressure Hydrocephalus is characterized by gait disturbance, cognitive impairment, and urinary incontinence. Symptom improvement can be achieved by shunt surgery, especially regarding gait difficulties. This study investigated whether CSF volumetry can define postoperative target values associated with clinical improvement and, secondly, predict potential non-response or overdrainage complications.</p><p><strong>Materials and methods: </strong>Forty-seven patients with iNPH were prospectively followed for three years after shunt surgery. Quantitative MRI was performed at baseline and at 3, 12, and 36 months postoperatively. Automatic segmentation yielded ventricular volume, subarachnoid CSF volume, ratio of ventricular and total CSF volume and ratio of total brain volume and intracranial volume. Clinical outcome was assessed using the Hellström iNPH scale. Patients were classified as responders and non-responders and further subdivided with and without overdrainage complications.</p><p><strong>Results: </strong>Eighty-seven percent of patients were classified as responders. Responders demonstrated a 26% reduction in ventricular volume(139 ml at baseline and 102 ml at three years) accompanied by a >60% improvement in iNPH score. The ventricular/total CSF ratio decreased from 0.34 to 0.25. Non-responders exhibited low ratios already at baseline, due to a significantly higher subarachnoid CSF volume. Overdrainage-related postural headaches were associated withlow subarachnoid CSF volume, younger age, higher baseline iNPH score, and higher BPV/ICV ratio. Aggregate z-scores combining multiple baseline metrics improved discrimination between responders, non-responders, and patients at risk for overdrainage.</p><p><strong>Conclusions: </strong>Baseline volumetry may provide target values and risk stratification for shunt surgery in iNPH. Responders showed a reduction of ventricular volume to ∼100 ml and ventricle/total CSF ratio to ∼0.25. High subarachnoid CSF volumes at baseline, however, was associated with poor response, while low subarachnoid CSF volume indicated an increased risk of postural headache. Quantitative CSF segmentation may improve patient selection and postoperative management in iNPH.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149225502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Edaravone dexborneol for acute ischaemic stroke among patients undergoing endovascular treatment: a systematic review and meta-analysis.","authors":"Paweł Łajczak, Luiz Henrique Alves Nogueira, João Vitor Andrade Fernandes, Ocilio Ribeiro Gonçalves, Luciano Falcão, Adil Ahmed, Anna Łajczak, Ahmet Günkan, Thanh N Nguyen, Mohamad Abdalkader, Gregoire Boulouis, Nicolas Chausson, Frédéric Clarençon, Luca Scarcia","doi":"10.3174/ajnr.A9686","DOIUrl":"https://doi.org/10.3174/ajnr.A9686","url":null,"abstract":"<p><strong>Background: </strong>Acute ischaemic stroke (AIS) remains a major cause of disability and mortality worldwide. Endovascular treatment (EVT) is the standard of care for large vessel occlusion, yet a favourable neurological outcome is not achieved in all patients. Edaravone dexborneol (ED) has been proposed as an adjuvant therapy during EVT procedures. However, its clinical impact has not been systematically synthesized.</p><p><strong>Methods: </strong>This systematic review and meta-analysis was conducted in accordance with the PRISMA guidelines. PubMed, Web of Science, Scopus, ClinicalTrials.gov, Cochrane Central, and Embase were searched from inception to March 2026. Randomized and non-randomized studies comparing ED versus non-ED (placebo) controls in AIS patients undergoing mechanical thrombectomy (MT) were included. The primary outcomes of this study were excellent and good neurological outcomes at 90 days, measured with the modified Rankin Scale. A random-effects meta-analysis was performed, with robust sensitivity analyses to explore heterogeneity.</p><p><strong>Results: </strong>Seven studies were included, of which three were randomized. For the primary outcomes, there was no significant difference in the proportion of patients with excellent (mRS 0-1: OR 1.14; 95% CI 0.95 to 1.36; p = 0.17) or good neurological outcome (mRS 0-2: OR 1.34; 95% CI 0.97 to 1.85; p = 0.08). The incidence of symptomatic intracranial hemorrhage (sICH) was similar between groups (OR 0.73; 95% CI 0.50 to 1.07; p = 0.11). Prediction intervals crossed the null for all efficacy outcomes. No significant differences were observed in mortality at 90 days (p = 0.51). However, in pooled adjusted analyses, ED was associated with a modest increase in good neurological outcome (aOR 1.46; 95% CI 1.13 to 1.90; p = 0.004).</p><p><strong>Conclusion: </strong>Unadjusted analyses show no significant benefit of ED in reducing mortality, symptomatic bleeding events, or improving functional recovery. However, pooled adjusted estimates suggest a modest improvement in good neurological outcomes (mRS 0-2). Wide prediction intervals crossing the null indicate that the current evidence is preliminary, and confirmation in adequately powered trials is needed before routine clinical adoption.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149225528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bilateral Versus Unilateral Middle Meningeal Artery Embolization for Standalone Treatment of Unilateral Chronic Subdural Hematoma.","authors":"Santiago Gomez-Paz, Mohamed M Salem, Sonam Thind, Ahmad Chahine, Jordan Curtis Xu, Michael J Lang, Bradley A Gross, Adnan H Siddiqui, Elad I Levy, Howard A Riina, Brian M Howard, Alexander Khalessi, Adam A Dmytriw, Diego A Ortega Moreno, Nicole M Cancelliere, Vitor Mendes Pereira, Robert W Regenhardt, William Smith, Christopher J Stapleton, Aman B Patel, Matthias Matejka, Christoph J Griessenauer, Christopher S Ogilvy, Alejandro M Spiotta, Daniel A Tonetti, Jane Khalife, Visish M Srinivasan, Jan-Karl Burkhardt, Michael R Levitt, Omar Tanweer, Tareq Kass-Hout, Jan Vargas, Ramesh Grandhi","doi":"10.3174/ajnr.A9680","DOIUrl":"https://doi.org/10.3174/ajnr.A9680","url":null,"abstract":"<p><strong>Background and purpose: </strong>Contralateral dural supply may leave residual membrane perfusion after unilateral middle meningeal artery embolization (MMAE) for unilateral chronic subdural hematoma (cSDH). We compared unilateral and bilateral MMAE selected as initial standalone treatment, focusing on index-admission surgical rescue and other clinically relevant outcomes.</p><p><strong>Materials and methods: </strong>This retrospective cohort included patients treated at 16 centers worldwide from 2018 through 2025. The primary endpoint was index-admission surgical rescue. The original 3:1 and confirmatory 1:1 propensity-matched analyses used prespecified baseline covariates. A composite sensitivity outcome of any retreatment was also examined post hoc.</p><p><strong>Results: </strong>Among 600 patients, 546 underwent unilateral and 54 bilateral MMAE. Bilateral cases had lower baseline radiographic severity and more often underwent general anesthesia and selective distal embolization. Index-admission surgical rescue occurred in 9.5% of unilateral and 0% of bilateral cases (p<0.001), with corresponding rates of 10.6% versus 0% after 3:1 matching (p<0.001) and 11.1% versus 0% after 1:1 matching (p<0.001). The post-hoc composite of any retreatment did not differ in the unmatched cohort (p=0.37), 3:1 cohort (p=0.56), or 1:1 cohort (>0.99). Other outcomes showed no statistically significant between-group differences, but postdischarge follow-up was incomplete.</p><p><strong>Conclusions: </strong>Overall retreatment did not differ between groups, although bilateral MMAE was associated with fewer index-admission surgical rescues. These observational data identify, but do not validate, angiographically documented contralateral supply as a candidate selection marker for prospective evaluation but do not establish a benefit of bilateral treatment or support routine bilateral MMAE.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149225260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Susceptibility Mapping of the Centromedian Nucleus and Indirect Comparison with Alternate Sequences.","authors":"Mohammed A Rasheed, Vivian Nguyen, Megan V Ryan, Steven G Ojemann, Daniel R Kramer, John A Thompson, Issam A Awad, David Satzer","doi":"10.3174/ajnr.A9681","DOIUrl":"https://doi.org/10.3174/ajnr.A9681","url":null,"abstract":"<p><strong>Introduction: </strong>Neuromodulation of the thalamic centromedian nucleus (CM) is an established therapy for epilepsy and been applied for pain, Tourette syndrome, and disorders of consciousness. Accurate targeting remains challenging because CM is poorly visualized on conventional MRI sequences, necessitating reliance on indirect targeting approaches. Although advanced MRI sequences, such as magnetization-prepared rapid acquisition of two gradient echoes (MP2RAGE) and white matter null (WMn), have been explored, they fail to reliably delineate the boundary between CM and lateral thalamus, a region associated with optimal stimulation outcomes, particularly in epilepsy. Quantitative susceptibility mapping (QSM) has emerged as a promising technique for differentiating thalamic nuclei based on tissue magnetic susceptibility.</p><p><strong>Objective: </strong>The purpose of this study was to evaluate visualization of CM using QSM, assess contrast between CM and adjacent nuclei, and indirectly compare across WMn and MP2RAGE.</p><p><strong>Methods: </strong>This retrospective study included patients with solitary cerebral cavernous malformations, not involving the thalamus, who underwent surveillance MRI including QSM (n=24). WMn sequences were obtained from a separate cohort of patients with epilepsy (n=16). MP2RAGE sequences were acquired from healthy individuals (n=24). All sequences were registered to the MNI152 template space and compared with the Morel histological atlas. Normalized intensity differences, contrast-to-noise ratios (CNR), and signal-to-noise ratios (SNR) were calculated for CM and neighboring nuclei.</p><p><strong>Results: </strong>On QSM, CM was hypointense to medial and posterior thalamus and hyperintense relative to motor thalamus. Median CNR on QSM (P<0.05) relative to CM was highest for medial pulvinar (median 2.9, interquartile range 1.6-4.7) and ventral lateral thalamus (1.6, 0.6-2.3). Highest overall CNR was seen on WMn for PuM (3.4, 3.0-4.0). SNR on QSM was highest for anterior pulvinar (2.4, 1.1-3.6) and highest overall SNR was on on MP2RAGE for PuA (20.8, 17.3-24.3). In an indirect comparison across independent cohorts, QSM showed greater lateral thalamic contrast than WMn and MP2RAGE, but lower overall SNR.</p><p><strong>Conclusion: </strong>QSM allows visualization of CM including the lateral border poorly seen on other sequences, and may be useful as a complementary sequence for direct targeting of CM.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149225543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carotid Body Detection Rate and Size on Photon-Counting Versus Energy-Integrating Detector CT.","authors":"Robert H Unger, Elly Arizono, Karen Buch, Osamu Sakai","doi":"10.3174/ajnr.A9684","DOIUrl":"https://doi.org/10.3174/ajnr.A9684","url":null,"abstract":"<p><strong>Purpose: </strong>To compare the carotid body (CB) detection rate and size measured on photon-counting CT (PCCT) versus energy-integrating detector CT (EIDCT), and to evaluate the effects of laterality and contrast phase.</p><p><strong>Methods: </strong>This retrospective study was conducted at a single institution on 48 adult patients who underwent head and neck CTA on both PCCT and EIDCT on arterial and venous phase imaging. CB detection was analyzed as a binary outcome using a mixed-effects logistic regression model with modality, phase, side, and modality-by-phase interaction as fixed effects, and patient as a random effect. CB size was analyzed using a linear mixed-effects model with the same fixed effects and patient as a random effect. Sensitivity analysis for CB size adjusted for age, sex, and hypertension.</p><p><strong>Results: </strong>CB detection rates were higher on PCCT than on EIDCT, particularly on the right side (arterial, 96% vs 77%; venous, 96% vs 82%), and slightly higher on the left side (arterial, 85% vs 81%; venous, 83% vs 82%). In mixed-effects logistic regression, PCCT was associated with higher odds of CB detection than EIDCT (OR, 3.97; P = .009). CB size was significantly smaller when measured on PCCT than on EIDCT (estimated difference, -2.7 mm³; P = .01). The right CB was larger than the left across modalities (estimated difference, +4.7 mm³; P < .001). There was no significant difference in CB measurements between arterial and venous phases (P = .53), and no significant modality-by-phase interaction (P = .98). In sensitivity analysis, the modality and side effects remained significant after adjustment for age, sex, and hypertension.</p><p><strong>Conclusion: </strong>PCCT improves CB detection compared with EIDCT but yields smaller CB measurements. CB size is greater on the right than on the left, with minimal effect of contrast phase. These findings remained robust after adjustment for age, sex, and hypertension.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149225510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcranial Focused Ultrasound: Established and Emerging Applications in Neurosciences.","authors":"Phuong Nguyen, Timothy J Kaufmann, Lubdha M Shah, Bhavya R Shah, Leo P Sugrue, Jody Tanabe","doi":"10.3174/ajnr.A9685","DOIUrl":"https://doi.org/10.3174/ajnr.A9685","url":null,"abstract":"<p><p>Transcranial MR-guided high-intensity focused ultrasound (HIFU) thermoablation is an established incisionless image-guided treatment for movement disorders; however, neuroradiologist involvement in clinical decision-making and procedural workflows is highly variable and site-specific. Transcranial low-intensity focused ultrasound (LIFU) is a rapidly evolving non-invasive, image-guided technology for neuromodulation and blood-brain barrier disruption. Compared with HIFU, the optimal protocol, therapeutic mechanism, and safety limits remain uncertain for LIFU. Despite these gaps, LIFU has significant potential for neuropsychiatric and neuro-oncologic diseases. Familiarity with transcranial ultrasound principles and the pivotal role of CT and MR imaging for targeting and evaluating outcomes is increasingly important for neuroradiologists. This review uses HIFU as a clinical model to illustrate the integration of imaging into focused ultrasound workflows. We then discuss LIFU with respect to technical factors, imaging considerations, safety, and limitations. We highlight its emerging applications, including neuromodulation, targeted drug delivery, and liquid biopsy. Finally, we conclude by summarizing key knowledge gaps, outlining future directions, and proposing strategies to more actively engage neuroradiologists in this emerging field.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149225476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Black Belt Sign on Diluted Contrast 3D Rotational Angiography as a Potential Neointimal Marker Associated with Intracranial Aneurysm Occlusion after Flow Diversion.","authors":"Shuhei Egashira, Yusuke Hamada, Satoru Kawauchi, Shogo Yoda, Yuta Otomo, Satoshi Miyamoto, Jun Isozaki, Daiichiro Ishigami, Wataro Tsuruta","doi":"10.3174/ajnr.A9343","DOIUrl":"10.3174/ajnr.A9343","url":null,"abstract":"<p><strong>Background and purpose: </strong>Neointimal formation at the aneurysm neck is essential after flow diverter (FD) treatment; however, reliable imaging markers are lacking. The white collar sign (WCS), an established endothelialization marker after coil embolization, is paradoxically associated with incomplete occlusion after flow diversion. We aimed to propose the black belt sign (BBS), an endoluminal bandlike filling defect on 3D rotational angiography (3DRA), as a neointimal marker, determine the optimal imaging technique, and assess its association with aneurysm occlusion.</p><p><strong>Materials and methods: </strong>This single center, retrospective cohort study included consecutive patients who underwent FD placement from April 2015 to December 2024, completed 6- and 12-month followups, and underwent diluted 3DRA, pure 3DRA, and high-resolution conebeam CT at 6-months. Three blinded assessors graded the 6-month BBS (none, partial, full). The optimal technique was determined by interrater reliability. The BBS stage was compared across 6-month O'Kelly-Marotta (OKM) grades using the Cochran Armitage test. Among 6-month incompletely occluded aneurysms, 12-month complete occlusion rates were compared by BBS stage, and risk ratios were estimated using modified Poisson regression with cluster robust SEs at the patient level. The WCS on 6-month 2D DSA was recorded, and detection rates were examined across BBS stages and OKM grades.</p><p><strong>Results: </strong>We analyzed 142 aneurysms in 123 patients. Diluted 3DRA showed superior interrater reliability (mean of all pair-wise weighted Cohen κ values [Light's κ] = 0.82). The predominant BBS stage transitioned from none to partial to full as the 6-month OKM grades improved (none/partial/full: OKM A, 62/38/0%; B, 25/75/0%; C, 3/59/38%; D, 1/7/91%, respectively; <i>P</i> for trend < .01). Among the 61 incompletely occluded aneurysms at 6-months, the 12-month complete occlusion rates were 10% for none-BBS, 22% for partial BBS, and 71% for full BBS. Compared with none-BBS, the risk ratio for 12-month occlusion was 2.16 (95% CI, 0.30-15.5) for partial BBS and 7.14 (95% CI, 1.07-47.8) for full BBS. The WCS was most frequent in aneurysms with partial BBS and OKM grade B (75%).</p><p><strong>Conclusions: </strong>Diluted 3DRA was identified as the optimal technique. The BBS aligned with the concurrent aneurysm occlusion status and predicted subsequent complete occlusion, supporting its potential as a neointimal biomarker after FD treatment. The WCS may reflect immature neointimal formation after flow diversion.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147679135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}