AJNR. American journal of neuroradiology最新文献

{"title":"Perfusion Angiography in reperfused ischemic stroke patients: differentiating between favorable and unfavorable outcome.","authors":"P Matthijs van der Sluijs, R Su, Bridget A Schoon, R A van de Graaf, S A P Cornelissen, A C G M van Es, P J van Doormaal, J Hofmeijer, B Roozenbeek, W H van Zwam, A van der Lugt, T van Walsum","doi":"10.3174/ajnr.A8936","DOIUrl":"https://doi.org/10.3174/ajnr.A8936","url":null,"abstract":"<p><strong>Background and purpose: </strong>The Thrombolysis in Cerebral Infarction (TICI) score determines the reperfusion grade on digital subtraction angiography (DSA) after endovascular treatment (EVT) in acute ischemic stroke patients. Despite successful macrovascular reperfusion, almost half of patients have poor clinical outcome. In addition to the large vessels, DSA also depicts the passage of contrast in the capillaries. We aim to study differences in DSA perfusion parameters generated from the time intensity curves (TICs) that might differentiate between good and poor clinical outcome in patients who achieved successful reperfusion.</p><p><strong>Materials and methods: </strong>Patients from the MR CLEAN Registry with an ICA, M1 and M2 occlusion and successful reperfusion (eTICI ≥2B) were selected. Perfusion parameters of the capillary pixels were computed on post-EVT DSA by deconvolving the TIC with the arterial input function obtained from the internal carotid artery. Four perfusion parameters were extracted: cerebral blood volume (CBV), cerebral blood flow (CBF), time to maximum CBF (Tmax) and mean transit time (MTT). The association between the perfusion parameters and favorable functional outcome at 90 days (0-2 mRS) was analyzed using logistic regression with adjustments for prognostic patient characteristics including eTICI.</p><p><strong>Results: </strong>In total 743 of 5768 patients were included. There was no association between eTICI scores and favorable functional outcome. In contrast, a shorter MTT and Tmax were associated with favorable functional outcome (adjusted odds ratio, 1.25 [95%CI 1.03-1.51], 1.39 [95%CI 1.06-1,82]). DSA-CBV and DSA-CBF were not significantly associated with mRS.</p><p><strong>Conclusions: </strong>Quantifying DSA perfusion parameters provides additional information about reperfusion status and could contribute in differentiating between favorable and unfavorable functional outcome. The code for producing the quantitative digital subtraction perfusion angiography is publicly available at: https://github.com/RuishengSu/perfDSAABBREVIATIONS: EVT＝ Endovascular thrombectomy.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145182353","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":"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":"10.3174/ajnr.A8818","url":null,"abstract":"<p><strong>Background and purpose: </strong>Emergent carotid artery stent placement (eCAS) performed during endovascular treatment (EVT) for acute ischemic stroke (AIS) is associated with increased rates of stent thrombosis. Very limited data are 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 or isolated carotid artery occlusion (ICAO), between November 2009 and September 2024.</p><p><strong>Results: </strong>A total of 220 patients were included in the study, of whom 207 had tandem lesions 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, interquartile range, 30-216) revealed 2 additional cases of stent occlusion (1.2%) 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 carotid artery stent placement, 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>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-25","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":"Accuracy of Tumor Surveillance of Pediatric Adamantinomatous Craniopharyngioma Using Noncontrast Brain MRI.","authors":"Keanu Chee, David M Mirsky, Ilana Neuberger, Yosef Dastagirzada, Emily Cooper, Todd C Hankinson","doi":"10.3174/ajnr.A8928","DOIUrl":"https://doi.org/10.3174/ajnr.A8928","url":null,"abstract":"<p><strong>Background and purpose: </strong>Adamantinomatous craniopharyngioma (ACP) is a benign but histologically complex brain tumor that arises in the sellar or suprasellar region. Contrast-enhanced MRI of the brain is the standard of care for radiologic follow-up. Numerous studies have demonstrated gadolinium retention in the brain and body as a result of gadolinium-based contrast agent (GBCA) usage in MRI. While the clinical consequences of GBCA retention remain unknown, the concern for potential injury combined with advances in noncontrast imaging has promoted efforts to determine the necessity for contrast enhancement in the care of pediatric patients, particularly those with brain tumors. This study aims to evaluate the agreement and interrater reliability between noncontrast and contrast-enhanced MRI in the routine surveillance of children with ACP.</p><p><strong>Materials and methods: </strong>We conducted a retrospective review of MR imaging for 25 patients with ACP undergoing routine imaging follow-up assessment. Pre- and postcontrast-enhanced MRI sequences were evaluated by 2 pediatric neuroradiologists. Three consecutive 1-year follow-up scans were graded based on the characteristics of the solid and cystic components of the residual lesion. Percent agreement and interrater reliability were determined for grading between contrasted and unenhanced MRI scans.</p><p><strong>Results: </strong>The mean age of patients was 8.72 ± 4.59 years, and the mean time between scans was 12.60 ± 4.08 months and 14.48 ± 7.77 months from the first to second and second to third scans, respectively. Interrater reliability between grading by using contrast-enhanced and unenhanced MRIs was high. We observed a Cohen κ of 0.961 (95% CI, 0.92-1.0) when evaluating the cystic tumor and a Cohen κ of 0.80 (95% CI, 0.68-0.92) when assessing the solid tumor. The percent agreement between grading by using contrast-enhanced and unenhanced MRI for the cystic tumor component was 98.7% (74/75) for radiologist 1, and 97.3% (73/75) for radiologist 2. The percent agreement between grading by using contrast-enhanced and unenhanced MRI for the solid tumor component was 93.3% (70/75) for both radiologists.</p><p><strong>Conclusions: </strong>For children with ACP and known residual disease, noncontrast MRI may be sufficient for the assessment of solid tumor or cyst growth.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145152246","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":"3D Quantified Morphologic 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":"10.3174/ajnr.A8809","url":null,"abstract":"<p><strong>Background and purpose: </strong>The performance of the 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 morphologic parameters. In this longitudinal study, we aimed to identify standardized 3D quantified morphologic 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 and 2018. Using 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 morphologic parameters were quantified. Univariable and multivariable Cox proportional hazards models were used to identify 3D morphologic predictors of either aneurysm growth or 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 [interquartile range, 50-66]; 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 [interquartile range, 1.9-7.1]), major axis (hazard ratio, 1.16; 95% CI, 0.84-1.61) and shape index (hazard ratio, 1.53; 95% CI, 0.76-3.08) were retained, 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 [interquartile range, 2.1-7.3]): major axis (hazard ratio, 2.27; 95% CI, 1.36-3.80) and shape index (hazard ratio, 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 morphologic predictors of both aneurysm growth and rupture, but only for rupture did they demonstrate good discriminative power in our cohort. These parameters will need external validation and should be integrated with existing clinical prediction models.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-25","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}

{"title":"Subarachnoid Space Measurements in the Second Trimester Using MR Imaging.","authors":"Onur Simsek, Amirreza Manteghinejad, Mix Wannasarnmetha, Apoorva Kotha, Sara Reis Teixeira, Deborah Zarnow, Erin Simon Schwartz, Matthew T Whitehead","doi":"10.3174/ajnr.A8773","DOIUrl":"10.3174/ajnr.A8773","url":null,"abstract":"<p><strong>Background and purpose: </strong>The subarachnoid space is an important component of the developing intracranial compartment. As fetal brain MRI is becoming more commonplace for early CNS disease diagnosis, it is imperative to determine age-based standards for normal subarachnoid space depth. We aim to provide 2D reference measurements of the supratentorial subarachnoid spaces in apparently healthy mid and later second-trimester fetuses.</p><p><strong>Materials and methods: </strong>In this cross-sectional study, we included all singleton fetal brain MRIs between gestational weeks 19 and 27 without visible pathologies. The frontal, insular, and inferior temporal subarachnoid space widths were measured from the inner calvaria to the brain surface bilaterally. Intraclass coefficients (ICCs) and Bland-Altman plots were utilized to evaluate agreement between 2 raters. Left- and right-side measurements were compared by using Wilcoxon tests. Quade tests were used to compare measurements between boys and girls. Generalized additive modeling for location, scale, and shape was used to create centile curves.</p><p><strong>Results: </strong>A total of 159 cases were included. ICC was highest (0.943) for the coronal plane insula width and lowest (0.667) for the coronal plane frontal width. Neither left-right (<i>P</i> > .573) nor male-female (<i>P</i> > .102) measurements were significantly different when considering age as a confounder; therefore, a single chart was created for each measurement.</p><p><strong>Conclusions: </strong>Subarachnoid space depth adapts to the growing calvaria during the mid- to late second trimester. This study provides normal reference ranges for future clinical and research purposes.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143805175","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":"Automated Diffusion Analysis for Noninvasive Prediction of <i>Isocitrate Dehydrogenase</i> Genotype in WHO Grade 2-3 Gliomas.","authors":"Jiaming Wu, Stefanie C Thust, Stephen J Wastling, Gehad Abdalla, Massimo Benenati, John A Maynard, Sebastian Brandner, Ferran Prados Carrasco, Frederik Barkhof","doi":"10.3174/ajnr.A8776","DOIUrl":"10.3174/ajnr.A8776","url":null,"abstract":"<p><strong>Background and purpose: </strong>Glioma molecular characterization is essential for risk stratification and treatment planning. Noninvasive imaging biomarkers such as ADC values have shown potential for predicting glioma genotypes. However, manual segmentation of gliomas is time-consuming and operator-dependent. To address this limitation, we aimed to establish a single-sequence-derived automatic ADC extraction pipeline by using T2-weighted imaging to support glioma <i>isocitrate dehydrogenase (IDH)</i> genotyping.</p><p><strong>Materials and methods: </strong>Glioma volumes from a hospital data set (University College London Hospitals [UCLH]; <i>n</i> = 247) were manually segmented on T2-weighted MRI scans by using ITK-Snap Toolbox and coregistered to ADC map sequences by using the FMRIB Linear Image Registration Tool in FSL, followed by ADC histogram extraction (Python). Separately, a nnUNet deep learning algorithm was trained to segment glioma volumes by using T2-weighted sequences only from Brain Tumor Segmentation Challenge (BraTS) 2021 data (<i>n</i> = 500, 80% training, 5% validation, and 15% test split). nnUNet was then applied to the UCLH data for segmentation and ADC readouts. Univariable logistic regression was used to test the performance manual and nnUNet derived ADC metrics for IDH status prediction. Statistical equivalence was tested (paired 2-sided <i>t</i> test).</p><p><strong>Results: </strong>nnUNet segmentation achieved a median Dice of 0.85 on BraTS data, and 0.83 on UCLH data. For the best performing metric (normalized <i>ADC_mean</i> ) the area under the receiver operating characteristic curve (AUC) for differentiating IDH-mutant from IDH-wild-type gliomas was 0.82 (95% CI, 0.78-0.88), compared with the manual segmentation AUC 0.84 (95% CI, 0.77-0.89). For all ADC metrics, manually and nnUNet-extracted ADC were statistically equivalent (<i>P</i> < .01). nnUNet identified 1 area of glioma infiltration missed by human observers. In 0.8% gliomas, nnUNet missed glioma components. In 6% of cases, oversegmentation of brain remote from the tumor occurred (eg, temporal poles).</p><p><strong>Conclusions: </strong>The T2-weighted trained nnUNet algorithm achieved ADC readouts for IDH genotyping with a performance statistically equivalent to human observers. This approach could support rapid ADC-based identification of glioblastoma at an early disease stage, even with limited input data. Artificial intelligence level of evidence: 5A.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144268156","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":"Association of MRI-Visible Perivascular Spaces with Early White Matter Injury.","authors":"Arturo Toro, Frances Rodriguez Lara, Adlin Pinheiro, Serkalem Demissie, Charles DeCarli, Pedram Parva, Mohamad Habes, Andreas Charidimou, Sudha Seshadri, Pauline Maillard, Jose Rafael Romero","doi":"10.3174/ajnr.A8823","DOIUrl":"10.3174/ajnr.A8823","url":null,"abstract":"<p><strong>Background and purpose: </strong>MRI-visible perivascular spaces (PVS) are considered markers of cerebral small vessel disease (CSVD) and may reflect dysfunction of brain perivascular drainage. WM integrity assessed with DTI provides a sensitive assessment of early brain injury, related vascular risk factors, and risk of stroke and dementia. We investigated the relationship between PVS and WM integrity in community-dwelling participants.</p><p><strong>Materials and methods: </strong>Framingham Heart Study (FHS) participants with brain MRI, PVS ratings, and DTI measures were included. PVS were rated in the basal ganglia (BG) and centrum semiovale (CS) and categorized into grades I-IV based on counts. We related PVS burden to global DTI measures (free water fraction [FW], fractional anisotropy [FA], peak skeletonized mean diffusivity [PSMD]), diffusion along perivascular spaces (DTI-ALPS), and voxel-based measures using multivariable linear regression analyses.</p><p><strong>Results: </strong>Among 3077 participants (57.2 mean age; 53% women), 7% had high-burden PVS in the BG, and 13% had high burden in the CS. High PVS burden in either or both regions was associated with higher global FW, PSMD, lower global FA, and lower DTI-ALPS index in fully adjusted models (<i>P</i> < .001). Voxel analyses revealed significant associations between high PVS burden in both regions and FW involving ascending, descending, interhemispheric, and intrahemispheric tracts (<i>P</i> < .0001) but not with FA.</p><p><strong>Conclusions: </strong>PVS burden was associated with early signs of global WM injury after adjustment for vascular risk factors, suggesting that high PVS burden may represent early brain injury related to CSVD or impaired perivascular function.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144217829","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":"Postradiation MR Imaging Features in Molecular and Mutational Analyses in Pontine Pediatric Diffuse Midline Gliomas.","authors":"V Rameh, A Ziaei, S Vajapeyam, N Chen, W B London, K Wright, T Y Poussaint","doi":"10.3174/ajnr.A8817","DOIUrl":"10.3174/ajnr.A8817","url":null,"abstract":"<p><strong>Background and purpose: </strong>We aimed to describe the postradiation 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 institutional review board-approved, multicenter clinical trial: Molecularly Determined Treatment of Diffuse Intrinsic Pontine Glioma. Subjects had baseline MR imaging that showed classic imaging criteria of pontine diffuse midline glioma and postradiation 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 epidermal growth factor receptor expression in the biopsy specimen. Imaging analyses included postradiation 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 postradiation. The mutation subgroups were compared by 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 of 35 (29%) had <i>H3C2/3</i>, and 8 of 35 (22%) were wild-type (WT). Except for enhancing volume at postradiation time point 2 (4 months postradiation; RT2), all imaging features had a statistically significant change (<i>P</i> < .05) from baseline to time point 1 (2 months postradiation; RT1) and RT2. Within the cohort of patients that had H3-mutant tumors (<i>n</i> = 27), patients with <i>H3C2/3</i> had statistically significantly higher mean nADC_FLAIR (<i>P</i> = .05), mode nADC_FLAIR (<i>P</i> = .003), median nADC_FLAIR (<i>P</i> = .02), and mode nADC-enhancement (<i>P</i> = .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 postradiation, when we compared H3-mutant versus WT tumors.</p><p><strong>Conclusions: </strong>Postradiation MR imaging features are differentially correlated with the underlying mutational status of pediatric pontine diffuse midline glioma.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-25","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":"Photon-Counting Computed Tomography for Evaluation of Coiled Intracranial Aneurysms.","authors":"B Mac Grory, Amanda Randles, David M Urick, Fides R Schwartz, David Hasan, Evan D Calabrese","doi":"10.3174/ajnr.A9015","DOIUrl":"10.3174/ajnr.A9015","url":null,"abstract":"<p><strong>Background and purpose: </strong>Intracranial aneurysms treated with endovascular embolization often require surveillance imaging using digital subtraction angiography, an invasive, risky, and expensive procedure. Existing non-invasive imaging modalities (standard computed tomography [CT] or magnetic resonance [MR] angiography) are often unsatisfactory for evaluating treated aneurysm due to artifacts from embolization devices. The objective of the present study was to determine whether photon-counting computer tomography (PCCT) imaging parameters could be optimized to confer satisfactory imaging resolution in an anthropomorphic phantom of treated intracranial aneurysms.</p><p><strong>Materials and methods: </strong>Phantom studies were performed using a model of the major intracranial arteries with appropriately sized, endovascularly treated middle cerebral artery (coil embolization) and basilar artery (woven endobridge [WEB] embolization) aneurysms. A series of imaging acquisition procedures were performed using a conventional energy-integrating CT (EICT) scanner and a photon-counting CT (PCCT) scanner. Key imaging acquisition and reconstruction parameters were varied to identify the optimum protocol for treated aneurysm characterization. Artifact reduction was performed on all images using the Siemens iterative metal artifact reduction (iMAR) algorithm. Contrast-to-noise ratio and metal artifact magnitude were quantitatively analyzed and displayed in tabular form to provide objective criteria for determination of optimal processing parameters for treated aneurysm visualization.</p><p><strong>Results: </strong>Imaging was successfully obtained in phantom studies across a range of imaging parameters. Quantitative metal artifact magnitude was greater for 100keV virtual monoenergetic images (VMIs) and lowest for 55 keV VMIs without iMAR, but this trend was reversed with iMAR applied. The 55 keV VMI was chosen as the optimal reconstruction parameter for visualization of treated intracranial aneurysms as it demonstrated low magnitude of metal artifacts and the highest contrast-to-noise ratio (CNR) in adjacent vasculature. Similarly, CNR of the largest vessel adjacent to the coil mass was increased for all images after iMAR was applied. CNR was highest in the 55 keV VMR images both before (3.61±0.14) and after (6.82±0.34) application of iMAR.</p><p><strong>Conclusions: </strong>Virtual monoenergetic images combined with metal artifact reduction algorithms created from PCCT scans conferred excellent visualization of previously-treated intracranial aneurysms and adjacent vasculature. It was feasible to extend these results to preliminary clinical applications in human patients.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12499875/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093327","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":"Multi-modal CT Perfusion-based Deep Learning for Predicting Stroke Lesion Outcomes in Complete and No Recanalization Scenarios.","authors":"Hongxi Yang, Yasmeen George, Deval Mehta, Longting Lin, Chushuang Chen, David Yang, Jiacheng Sun, Kin Fung Lau, Chris Bain, Qing Yang, Mark W Parsons, Zongyuan Ge","doi":"10.3174/ajnr.A9016","DOIUrl":"https://doi.org/10.3174/ajnr.A9016","url":null,"abstract":"<p><strong>Background and purpose: </strong>Predicting the final location and volume of lesions in acute ischemic stroke (AIS) is crucial for clinical management. While CT perfusion (CTP) imaging is routinely used for estimating lesion outcomes, conventional threshold-based methods have limitations. We developed specialized outcome prediction deep learning models that predict infarct core in successful reperfusion cases and the combined core-penumbra region in unsuccessful reperfusion cases.</p><p><strong>Materials and methods: </strong>We developed single-modal and multi-modal deep learning models using CTP parameter maps to predict the final infarct lesion on follow-up diffusion-weighted imaging (DWI). Using a multi-center dataset from multiple sites, deep learning models were developed and evaluated separately for patients with complete recanalization (CR, successful reperfusion, n=350) and no recanalization (NR, unsuccessful reperfusion, n=138) after treatment. The CR model was designed to predict the infarct core region, while the NR model predicted the expanded hypoperfused tissue encompassing both core and penumbra regions. Five-fold cross-validation was performed for robust evaluation.</p><p><strong>Results: </strong>The multi-modal 3D nnU-Net model demonstrated superior performance, achieving mean Dice scores of 35.36% in CR patients and 50.22% in NR patients. This significantly outperformed the current clinical used method, providing more accurate outcome estimates than the conventional single-modality threshold-based measures which yielded dice scores of 15.73% and 39.71% for CR and NR groups respectively.</p><p><strong>Conclusions: </strong>Our approach offered both successful reperfusion and unsuccessful reperfusion estimations for potential treatment outcomes, enabling clinicians to better evaluate treatment eligibility for reperfusion therapies and assess potential treatment benefits. This advancement facilitates more personalized treatment recommendations and has the potential to significantly enhance clinical decision-making in AIS management by providing more accurate tissue outcome predictions than conventional single-modality threshold-based approaches.</p><p><strong>Abbreviations: </strong>AIS=acute ischemic stroke; CR=complete recanalization; NR=no recanalization; DT=delay time; IQR=interquartile range; GT=ground truth; HD95=95% Hausdorff distance; ASSD=average symmetric surface distance; MLV=mismatch lesion volume.</p>","PeriodicalId":93863,"journal":{"name":"AJNR. American journal of neuroradiology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093303","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}