AJNR. American journal of neuroradiology最新文献

{"title":"The Cortical Vein Opacification Score (COVES) Is Independently Associated with DSA ASITN Collateral Score.","authors":"Dhairya A Lakhani, Aneri B Balar, Subtain Ali, Musharaf Khan, Hamza Salim, Manisha Koneru, Sijin Wen, Richard Wang, Janet Mei, Argye E Hillis, Jeremy J Heit, Greg W Albers, Adam A Dmytriw, Tobias D Faizy, Max Wintermark, Kambiz Nael, Ansaar T Rai, Vivek S Yedavalli","doi":"10.3174/ajnr.A8601","DOIUrl":"10.3174/ajnr.A8601","url":null,"abstract":"<p><strong>Background and purpose: </strong>Pretreatment CTA-based Cortical Vein Opacification Score (COVES) has been shown to predict good functional outcomes at 90 days in patients with acute ischemic stroke secondary to large vessel occlusion (AIS-LVO). This is thought to be related to its ability to measure collateral status (CS). However, its association with the reference standard test, the DSA-based American Society of Interventional and Therapeutic Neuroradiology (ASITN) collateral score, has yet to be established. Therefore, this study assesses the relationship between COVES and ASITN CS.</p><p><strong>Materials and methods: </strong>In this prospectively collected, retrospectively reviewed analysis, patients with anterior circulation LVO from September 1, 2017, to October 1, 2023, were included. The COVES grading, which ranges from 0 to 6, was independently assessed by 2 board-certified neuroradiologists. The ASITN CS was independently assessed by a board-certified neuroradiologist and the performing neurointerventionalist. Any discrepancies were resolved through consensus review. Spearman rank correlation, univariable logistic regression, multivariable logistic regression, and receiver operating characteristic curve analysis were performed. A <i>P</i> value of ≤ .05 was considered significant.</p><p><strong>Results: </strong>In total, 311 consecutive patients (median, IQR = 68 years [59-78 years]; 55.9% women) met our inclusion criteria. There was significant positive correlation between COVES and ASITN CS (ρ = 0.41, <i>P</i> < .001), and higher COVES was significantly and independently associated with good ASITN CS (unadjusted-OR = 1.74, <i>P</i> < .001) and adjusted-OR = 1.73, <i>P</i> < .001). Receiver operating characteristic curve analysis showed area under the curve of 0.71, <i>P</i> < .001).</p><p><strong>Conclusions: </strong>By demonstrating the independent association of COVES with the reference standard test for collateral status assessment, the ASITN CS, we further validate the role of COVES in estimating collateral status.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":"921-928"},"PeriodicalIF":0.0,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12091969/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long term stent patency and revascularization rates after emergent carotid stenting during stroke thrombectomy.","authors":"Alexandru Dimancea, Axelle Y Kern, Francois Severac, Anca Hasiu, Ian Leonard-Lorant, Roxana Gheoca, Emmanuel Wiener, Véronique Quenardelle, Valérie Wolff, Rémy Beaujeux, Pierre Mangin, Raoul Pop","doi":"10.3174/ajnr.A8818","DOIUrl":"https://doi.org/10.3174/ajnr.A8818","url":null,"abstract":"<p><strong>Background and purpose: </strong>Emergent carotid artery stenting (eCAS) performed during endovascular treatment (EVT) for acute ischemic stroke (AIS) is associated with increased rates of stent thrombosis. Very limited data is available regarding long-term carotid stent patency or target lesion revascularization (TLR) rates beyond the first 24 hours post EVT.</p><p><strong>Materials and methods: </strong>We retrospectively analyzed a prospectively maintained stroke EVT database at Strasbourg University Hospitals, including all consecutive patients treated with eCAS during EVT for AIS with tandem lesions (TL) or isolated carotid artery occlusion (ICAO), between November 2009-September 2024.</p><p><strong>Results: </strong>A total of 220 patients were included in the study, of which 207 TL and 13 ICAO. Stent occlusion or severe stenosis at 24 hours was observed in 8.6% of cases. Follow-up imaging beyond day 1 (median 112 days, IQR 30-216) revealed two additional cases of stent occlusion (1.3%) at day 4 and 5. In-stent restenosis (at least 50%) was observed in 4.3% of cases after a median interval of 13 months; all these patients had underlying carotid atheroma. TLR was performed in 3% of cases. The cumulative incidences of restenosis at 1 and 2 years were 9.8% (95%CI 0.8-18.8) and 22% (95%CI 3.3-40.7%) respectively.</p><p><strong>Conclusions: </strong>Stent occlusion was predominantly observed within the first 24 hours, with only rare occurrences thereafter. The incidence of long-term in-stent restenosis aligns with previously reported rates for elective CAS, performed outside the context of acute stroke EVT. Further prospective research is required to reduce the rates of stent occlusion within the first 24 hours.</p><p><strong>Abbreviations: </strong>eCAS = emergent carotid artery stenting; EVT = endovascular treatment; TLR = target lesion revascularization; TL = tandem lesions; ICAO = isolated carotid artery occlusion; IQR = interquartile range; CAS = carotid artery stenting; LVO = large vessel occlusion; AIS = acute ischemic stroke; sICH = symptomatic intracranial hemorrhage; DAPT = dual antiplatelet treatment; mTICI = modified Thrombolysis in Cerebral Infarction scale; HI1, HI2 = hemorrhagic infarction type 1, type 2; PH1, PH2 = parenchymal hematoma type 1, type 2.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144045855","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":"Remote Robotic Neurointervention: Overcoming Procedural and Connectivity Challenges.","authors":"Gary R Duckwiler, Charles B Beaman, Michael Kilpatrick, Daniel L Cooke, Kazim H Narsinh, Geoffrey P Colby, David J Bell, Ben Waldau","doi":"10.3174/ajnr.A8807","DOIUrl":"https://doi.org/10.3174/ajnr.A8807","url":null,"abstract":"<p><strong>Background and purpose: </strong>Access to endovascular interventions for neurointerventional procedures remains concentrated in metropolitan centers, limiting availability in smaller cities, rural regions, and developing nations. The feasibility of remote robotic intervention faces several challenges, including enabling full robotic navigation, managing contrast injection, and maintaining stable network connectivity. This study addresses these key obstacles.</p><p><strong>Methods: </strong>A robotic system was deployed at the Translational Research Imaging Center (TRIC) lab at UCLA. Connectivity was assessed both before and during the procedures. Five remote Neurointerventionalists operated four devices-two novel steerable catheters, one off-the-shelf microcatheter, and one guidewire-from femoral access to the middle cerebral artery (MCA) in a silicone vascular model. Radiopaque contrast injections were performed, and audiovisual communication was maintained throughout. Connectivity metrics, including round-trip time (RTT) and bandwidth, were monitored. Primary endpoints included successful navigation to the MCA within 15 minutes, first-attempt vessel entry rate, and episodes of tool-tip contact with the vessel wall.</p><p><strong>Results: </strong>Following catheter placement in the femoral sheath, all procedures were fully robotically controlled without bedside intervention. Procedural times ranged from 11:01 to 14:00 minutes, with a mean RTT below 150ms. Two brief episodes of unsafe latency (RTT >150 ms) were recorded. First-attempt vessel entry was successful in 84.2% of cases, and minimal vessel wall contact occurred (1-2 episodes per procedure).</p><p><strong>Conclusions: </strong>This study demonstrates the feasibility of remote robotic neurointervention, effectively addressing key challenges in robot-assisted endovascular procedures and network connectivity management.</p><p><strong>Abbreviations: </strong>PTZ = Pan Tilt Zoom Camera; RTT = round-trip time; TRIC = Translational Research Imaging Center lab at UCLA; RR = Remedy Robotics; LCCA = Left Common Carotid Artery; RCFA = right common femoral artery; ACA = Anterior Cerebral Artery; ICA = Internal Carotid Artery.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144054458","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":"Plaque RADS Related to Cerebrovascular Event Risk with Mild/moderate Stenosis: a CARE II study.","authors":"Maoxue Wang, Yin Guo, Daniel S Hippe, Xihai Zhao, Chun Yuan, Luca Saba, Bing Zhang, Mahmud Mossa-Basha","doi":"10.3174/ajnr.A8819","DOIUrl":"https://doi.org/10.3174/ajnr.A8819","url":null,"abstract":"<p><strong>Background and purpose: </strong>Carotid Plaque-Reporting And Data System (Plaque-RADS) provides a standardized approach for evaluating carotid plaque morphology and composition. The aim of this study was to evaluate carotid Plaque-RADS, and its relationship with clinical risk factors and ipsilateral cerebrovascular symptoms, in a prospectively-acquired multi-center, vessel-wall MRI dataset.</p><p><strong>Materials and methods: </strong>Symptomatic patients were recruited from the CARE-II (Chinese Atherosclerosis Risk Evaluation, NCT02017756) study. This cross-sectional study included patients with recent stroke or transient ischemia attack and atherosclerotic plaques in at least one carotid artery. Lipid-rich necrotic core, ulceration, intraplaque hemorrhage, thick or thin fibrous cap, fibrous cap rupture and intraluminal thrombi were identified from multiple contrast vessel wall imaging and used to determine carotid Plaque-RADS. In addition, ancillary features including calcification and plaque burden via maximum normalized wall index (max_NWI) were collected. Degree of stenosis was classified as mild (<30%), moderate (30-69%), and severe (70-99%). Generalized Estimating Equation-based logistic regression was performed to assess the relationship between the Plaque-RADS score and cerebrovascular events.</p><p><strong>Results: </strong>A total of 433 patients (62 years ± 9.97, 302 males (69.7%)) with 866 carotid arteries were included in this study. Symptomatic carotid arteries had higher stenosis degree (11.8%±24.7 vs 8.6%±18.8, p=0.01), plaque-RADS score (≥3: 33.9% vs 28.4%, p=0.02) and max_NWI (0.53±0.14 vs 0.51±0.13, p=0.002) compared to the asymptomatic side. Plaque RADS was significantly associated with cerebrovascular events (OR=1.11 per 1-level increase, 95%CI=1.01-1.24; p=0.04). In patients with mild/moderate bilateral carotid artery stenosis, plaque RADS≥3 was significantly associated with symptomatic events (OR=1.30, 95%CI=1.01-1.68; p=0.04). Higher plaque-RADS on the symptomatic side was related to advanced age (OR=1.27 per 10-year increase, 95%CI=1.03-1.56; p=0.03), male sex (OR=1.90, 95%CI=1.05-3.43; p=0.03), and smoking history (OR=1.99, 95%CI=1.20-3.31; p=0.007).</p><p><strong>Conclusions: </strong>Male patients of advanced age and with a smoking history were associated with an increased risk of higher plaque-RADS scores. Plaque-RADS demonstrated the ability to stratify patients experiencing cerebrovascular events, even in cases with mildto-moderate stenosis. However, this association did not retain statistical significance after adjusting for stenosis or max_NWI.</p><p><strong>Abbreviations: </strong>IPH = intraplaque hemorrhage; Max-NWI = maximum normalized wall index; MWT = maximum wall thickness; RADS = Reporting And Data System; VWI = vessel wall imaging.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144044693","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":"Assessment of\" Zero-Shot\" General Purpose Segmentation Models: An Analysis of the Meta \"Segment Anything Model\" on Meningioma MRI.","authors":"Rushmin Khazanchi, Sachin Govind, Harrshavasan T Congivaram, Rishi Jain, Nishanth S Sadagopan, Stephen T Magill","doi":"10.3174/ajnr.A8816","DOIUrl":"https://doi.org/10.3174/ajnr.A8816","url":null,"abstract":"<p><strong>Background and purpose: </strong>Newly developed zero-shot segmentation algorithms, like Meta's \"Segment Anything Model 2\" (SAM2), have the potential to automate segmentation processes more efficiently than existing solutions. The goal of this study was to assess the ability of SAM2 to segment meningioma MRIs and suggest paradigms to enhance and assess performance.</p><p><strong>Materials and methods: </strong>We used SAM2 to produce segmentation masks using T1-weighted MRIs within the 2023 BraTS Preoperative Meningioma Dataset. We also proposed interactive click-based and contour-based augmentation strategies to simulate a neuroradiologist's workflow, alongside a novel ensembling method. Analyses evaluated performance across model iterations both overall and within clinical subgroups of interest using standard statistical techniques and measures.</p><p><strong>Results: </strong>Our cohort included a total of 690 meningiomas, the majority being WHO Grade 1 (75%). SAM2 achieved an overall zero-shot segmentation average Dice score of 0.785. Both click-based and contour-based augmentation strategies provided significant model improvement (0.876 and 0.872, respectively, p < 0.001). Layering a directional consensus approach on top of the contour-based model further enhanced performance (0.921, p < 0.001). Across all model iterations, smaller tumor volumes and tumors without peritumoral edema proved more difficult for SAM2 to segment (p < 0.001).</p><p><strong>Conclusions: </strong>SAM2 demonstrated reasonable zero-shot segmentation performance on meningioma MRIs, with observable improvements seen with contour-based prompting and directional ensembling. These results suggest that zero-shot segmentation models, with some degree of radiologist assistance or intervention, are promising tools for aiding in image segmentation for meningioma. Future work can investigate methods to improve segmentation performance for small tumor volumes and tumors without peritumoral edema.</p><p><strong>Abbreviations: </strong>SAM2 - Segment Anything Model 2; ML - Machine Learning; CNN - Convolutional Neural Network; DSC - Dice Similarity Coefficient; GT - Ground Truth.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144037460","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":"Post-radiation MR imaging features in Molecular and Mutational Analyses in Pontine Pediatric Diffuse Midline Gliomas.","authors":"Vanessa Rameh, Alireza Ziaei, Sridhar Vajapeyam, Nan Chen, Wendy B London, Karen Wright, Tina Y Poussaint","doi":"10.3174/ajnr.A8817","DOIUrl":"https://doi.org/10.3174/ajnr.A8817","url":null,"abstract":"<p><strong>Background and purpose: </strong>We aimed to describe the post-radiation imaging features in children with pontine pediatric diffuse midline glioma, and to identify associations between these changes and histone mutational status, as well as overall survival.</p><p><strong>Materials and methods: </strong>Patients were recruited as part of an IRB approved, multicenter clinical trial: Molecularly Determined Treatment of pontine diffuse midline glioma. Subjects had baseline MR imaging that showed classic imaging criteria of pontine diffuse midline glioma and post radiation imaging at regular intervals. All patients underwent biopsy before therapy initiation and received standard radiation therapy with adjuvant bevacizumab. Patients were subsequently stratified based on methylation status and EGFR expression in the biopsy specimen.Imaging analyses included post-radiation T2/FLAIR and enhancing tumor volumes, as well as normalized ADC (nADC) histogram metrics (mean, median, mode, skewness, and kurtosis) at 2 and 4 months post-radiation. The mutation sub-groups were compared using a Wilcoxon rank-sum test.</p><p><strong>Results: </strong>Forty-one patients met eligibility criteria, and mutational status was identified in 35. The median age was 6 years (range: 1.2-17). Seventeen of 35 (49%) had <i>H3-3A</i> histone mutations, 10/35 (29%) had <i>H3C2/3</i>, and 8/35 (22%) were wild type (WT).Except for enhancing volume at RT2, all imaging features had a statistically significant change (p<0.05) from baseline to RT1 and RT2.Within the cohort of patients that had H3-mutant tumors (n=27), patients with <i>H3C2/3</i> had statistically significantly higher mean nADC_FLAIR (p=0.05), mode nADC_FLAIR (p=0.003), median nADC_FLAIR (p=0.02), and mode nADC-enhancement (p=0.04) than patients with H3-3A at RT1. These nADC histogram metrics were not statistically significantly different at RT2.Moreover, we found no statistically significant difference in ADC histogram metrics post radiation, when we compared H3-mutant versus WT tumors.</p><p><strong>Conclusions: </strong>Post-radiation MR imaging features are differentially correlated with the underlying mutational status of pediatric pontine diffuse midline glioma.</p><p><strong>Abbreviations: </strong>Pediatric pontine diffuse midline glioma=pDMG Diffuse intrinsic pontine glioma= DIPG Epidermal growth factor receptor=EGFR Overall survival=OS Radiotherapy=RT Progression-free survival=PFS Contrast-enhanced=CE Post-radiation time point 1 (2 months post-radiation)=RT1 Post-radiation time point 2 (4 months post-radiation)=RT2.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144009719","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":"Portable Bedside Low-field MRI for Assessment of Ventricular Size.","authors":"Vinu Mathew, Timothy R Lim, Akhil Nair, Amy W Lin, Joel Kosowan, Yingming A Chen, Aditya Bharatha, Shobhit Mathur","doi":"10.3174/ajnr.A8811","DOIUrl":"https://doi.org/10.3174/ajnr.A8811","url":null,"abstract":"<p><strong>Background and purpose: </strong>Low-field portable MRI (pMRI) has been shown to be a useful alternative neuroimaging tool in the emergency department (ED) and intensive care unit (ICU), potentially addressing challenges associated with the transport of critically ill patients. We aimed to evaluate the intermodality reliability between low-field pMRI and conventional neuroimaging (CN) for assessment of ventricular size and hydrocephalus.</p><p><strong>Materials and methods: </strong>This retrospective study included all patients who underwent point-of-care 64mT pMRI at a single tertiary hospital from March 30, 2022 to January 4, 2024, and had a follow-up CN, either CT or MRI, performed within 24 hours of the pMRI scan. Two raters independently evaluated pMRI images for presence of hydrocephalus while blinded to CN. Bifrontal diameter, maximum skull and Evans index were recorded. Interrater and intermodality agreement between pMRI and CN were evaluated by using the intraclass coefficient (ICC) and Cohen's kappa.</p><p><strong>Results: </strong>Fifty-six patients (mean age of 53.5 (± 14.6) years, 61% male) were included in this study. Hydrocephalus was identified in 12 (21%) on pMRI and 13 (23%) on CN. Interrater agreement on pMRI was almost perfect for bifrontal diameter (ICC 0.94, 95% CI 0.89-0.97), Evans index (ICC 0.92, 95%CI 0.86-0.95) and substantial for determination of hydrocephalus (κ = 0.72), all p <0.01. Intermodality agreement between pMRI and CN was also near perfect for averaged measurements of bifrontal diameter (ICC 0.94, 95% CI 0.88-0.97), Evans index (ICC 0.95, 95%CI 0.92-0.97) and determination of hydrocephalus (κ = 0.95), all p<0.01. Using CN as reference standard, pMRI had sensitivity and specificity of 92% (95% CI 0.85-0.99) and 100% (95% CI 1.0-1.0), respectively on qualitative visual assessment, and 80% (95% CI 0.70-0.90) and 98% (95% CI 0.94-1.0), respectively on quantitative assessment using an Evans index cut off of 0.3.</p><p><strong>Conclusions: </strong>Low-field pMRI demonstrated excellent interrater agreement and strong concordance with CN in assessing ventricular size, highlighting its potential as an effective point-of-care tool for neuro-critical care applications.</p><p><strong>Abbreviations: </strong>pMRI= portable MRI; CN = conventional neuroimaging; ED= emergency department; ICU= intensive care unit; ICC= intraclass coefficient; pCT= portable CT; TCS = Transcranial Sonography.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144060810","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":"An Atlas of Neonatal Neurovascular Imaging Anatomy as Depicted with Microvascular Imaging: The Intracranial Arteries.","authors":"Shawn Lyo, Colbey W Freeman, Santiago Martinez-Correa, Arastoo Vossough, Luis Octavio Tierradentro-Garcia, Misun Hwang","doi":"10.3174/ajnr.A8810","DOIUrl":"https://doi.org/10.3174/ajnr.A8810","url":null,"abstract":"<p><p>Neurosonography is an invaluable diagnostic tool for assessing the neonatal brain and typically includes grayscale and conventional Doppler imaging. Microvascular imaging (MVI) is an emerging imaging technique that offers promising potential in evaluating neonatal intracranial pathology. MVI allows for sensitive and detailed assessment of neurovascular anatomy that can be challenging to visualize with other imaging modalities. This enhanced visualization not only improves the reliability in identifying neurovascular landmarks but also allows more accurate identification and assessment of adjacent parenchymal and extra-axial structures. Our review aims to offer an atlas of neurovascular structures as visualized with MVI, intended as a reference for future research in this field. Here, we focus specifically on the appearance of the intracranial arterial circulation as seen on MVI.ABBREVIATIONS: ACA = Anterior cerebral artery; AChoA = Anterior choroidal arteries; BA = Basilar artery; CEUS = Contrast-enhanced ultrasound; CPA = Cerebellopontine angel; LA = Labyrinthine arteries; MVI = microvascular imaging; PCoAs = Posterior communicating arteries.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144038183","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":"Using Data-Driven Methods to Improve Brain Blood Flow Measurements in Cerebrovascular Disease with Dynamic Imaging.","authors":"Siddhant Dogra, Xiuyuan Wang, James Michael Gee, Yihui Zhu, Koto Ishida, Seena Dehkharghani","doi":"10.3174/ajnr.A8813","DOIUrl":"https://doi.org/10.3174/ajnr.A8813","url":null,"abstract":"<p><strong>Background and purpose: </strong>Cerebrovascular reactivity (CVR) is a widely studied biomarker of cerebral hemodynamics, commonly used in risk stratification and treatment planning in patients with steno-occlusive disease (SOD). Conventional use relies on normalization of estimates to contralateral hemisphere reference values, which is unsuitable for bilateral or indeterminate distributions of disease. We report upon a custom data-driven approach leveraging random forest classifiers (RFc) to identify candidate voxels for normalization in order to facilitate interrogation outside conditions of known unilateral SOD MATERIALS AND METHODS: We retrospectively analyzed 16 patients with unilateral SOD who underwent acetazolamide-augmented BOLD-MRI and DSC perfusion. Three RFc models were trained using leave-one-out cross-validation (LOOCV) to identify candidate voxels brain-wide whose CVR were within 10% of the normal hemispheric median: i. all voxels; ii. gray matter only; and iii. white matter only. Model input features included time-to-maximum (Tmax), mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume (CBV) from contemporaneous DSC. The median model-predicted reference CVR (CVRref) was compared to ground-truth medians in LOOCV, and its impact on threshold-based volumetric classification of CVR reduction assessed.</p><p><strong>Results: </strong>RFc models effectively predicted ground-truth CVR voxels, achieving median absolute percent differences of 12.8% (IQR: 5.0%-18.9%) using all voxels, 11.3% (IQR: 9.3%-16.1%) for gray matter, and 9.8% (IQR: 4.4%-16.9%) for white matter. Volumetric estimates of CVR reduction across thresholds for the models revealed excellent agreement between ground-truth and model estimates without statistically significant differences (p>0.01), excepting lowest white matter CVR thresholds. Model use in a small pilot deployment of bilateral SOD cases demonstrated the potential utility, enabling voxel-wise CVR assessment without reliance on contralateral reference.</p><p><strong>Conclusions: </strong>We present a novel data-driven approach for normalizing CVR maps in patients with bilateral or indeterminate SOD. Using an RFc, our method provides an individualized, brain-wide reference CVR, expanding the utility of CVR estimates beyond the typical constraints of unilateral disease, and with potential application to other, similarly constrained scenarios such as for SPECT or PET hemodynamic studies.</p><p><strong>Abbreviations: </strong>CVR = cerebrovascular reactivity; RFc = random forest classifier; SOD = steno-occlusive disease.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144053422","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":"Three-Dimensional Quantified Morphological Predictors of Intracranial Aneurysm Instability: A Longitudinal Study.","authors":"Maarten J Kamphuis, Laura T van der Kamp, Ruben P A van Eijk, Kimberley M Timmins, Gabriel J E Rinkel, Jeroen Hendrikse, Mervyn D I Vergouwen, Irene C van der Schaaf","doi":"10.3174/ajnr.A8809","DOIUrl":"https://doi.org/10.3174/ajnr.A8809","url":null,"abstract":"<p><strong>Background and purpose: </strong>The performance of current prediction models for intracranial aneurysm growth and rupture is suboptimal, and new markers are needed to improve prediction. There is a strong need for longitudinal studies that use standardized morphological parameters. In this longitudinal study, we aimed to identify standardized three-dimensional (3D) quantified morphological parameters as predictors of aneurysm growth or rupture during long-term follow-up.</p><p><strong>Materials and methods: </strong>We used a database of consecutive patients with saccular unruptured intracranial aneurysms diagnosed between 2008-2018. Employing a retrospective case-cohort design, we included a computer-generated random sample of aneurysms from the full cohort and aneurysms with growth or rupture during follow-up outside the random sample. The case-cohort design is efficient for low-incidence outcomes while maintaining the temporal association between exposure and outcome. Aneurysms were annotated on baseline CTA or MRA images, and 3D morphological parameters were quantified. Univariable and multivariable Cox proportional hazards models were used to identify 3D morphological predictors of either aneurysm growth or aneurysm rupture. An inverse sampling probability weight was applied to obtain unbiased estimates of the hazard ratios.</p><p><strong>Results: </strong>We included 278 patients (median age, 59 years [IQR50-66]; 209 women) with 327 aneurysms, of which 239 aneurysms were stable during follow-up (73%), 68 grew without subsequent rupture (21%), 7 grew with subsequent rupture (2%), and 13 ruptured without preceding growth (4%). In the multivariable model for growth prediction (median follow-up 4.1 years [IQR1.9-7.1]), 2 parameters were retained: major axis (HR 1.16, 95%CI: 0.84-1.61) and shape index (HR 1.53, 95%CI: 0.76-3.08), with a c-statistic of 0.56 (95%CI: 0.49-0.63). The same parameters were retained in the multivariable model for prediction of rupture (median follow-up 4.5 years [IQR2.1-7.3]): major axis (HR 2.27, 95%CI: 1.36-3.80) and shape index (HR 3.33, 95%CI: 0.95-11.62), with a c-statistic of 0.85 (95%CI: 0.77-0.94).</p><p><strong>Conclusions: </strong>We identified major axis and shape index as candidate 3D quantified morphological predictors of both aneurysm growth and rupture, but only for rupture these had good discriminative power in our cohort. These parameters will need external validation and should be integrated with existing clinical prediction models.</p><p><strong>Abbreviations: </strong>ELAPSS = Earlier subarachnoid hemorrhage, Location of the aneurysm, Age, Population, Size of the aneurysm, and Shape of the aneurysm; IBSI = imaging biomarker standardization initiative; PHASES = Population, Hypertension, Age, Size of aneurysm, Earlier SAH from another aneurysm, and Site of aneurysm; UIA = unruptured intracranial aneurysm.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144031819","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}