IntroductionThe role of intravenous tenecteplase (TNK) in patients with acute ischemic stroke presenting 4.5-24 hours after last known well remains uncertain.MethodsWe performed a systematic review and frequentist and Bayesian meta-analysis of Randomized Controlled Trials (RCTs) comparing TNK-containing with trial-specific non-TNK strategies in imaging-selected patients with anterior-circulation large- or medium-vessel occlusion treated 4.5-24 hours after last known well. Trials represented heterogeneous reperfusion paradigms. The primary efficacy outcome was mRS 0-1 at 90 days; other functional, neurological, reperfusion, and recanalization outcomes were secondary or exploratory, and hemorrhagic events were assessed separately as safety outcomes.ResultsFour multicenter RCTs comprising 1,589 patients were included. Frequentist analysis showed no significant difference in the primary outcome, mRS 0-1 at 90 days (OR 1.29, 95% CI 0.99-1.67), or in secondary functional outcomes and mortality. Symptomatic intracranial hemorrhage (OR 1.79, 95% CI 0.88-3.60) and parenchymal hematoma (OR 2.02, 95% CI 0.60-6.74) were numerically more frequent with TNK. No significant interaction was observed according to reperfusion strategy (P-interaction >0.36), although subgroup analyses were exploratory and underpowered. Bayesian analyses yielded estimates favoring TNK for excellent functional outcome (OR 1.29, 95% CrI 1.10-1.51) but also suggested increased risks of symptomatic intracranial hemorrhage (OR 1.79, 95% CrI 1.15-2.76) and parenchymal hematoma (OR 2.02, 95% CrI 1.14-3.47); these findings should be interpreted cautiously given their dependence on Bayesian model assumptions.ConclusionAcross heterogeneous reperfusion paradigms, TNK-containing strategies showed no consistent functional benefit, while hemorrhagic outcomes raised a potential safety signal. Pooled estimates should not be interpreted as a uniform treatment effect.
BackgroundJapanese encephalitis (JE) is a mosquito-borne disease caused by a flavivirus and responsible for significant morbidity and mortality. Asymmetrical deep nuclei involvement is the characteristic Magnetic Resonance Imaging finding. However, it fails to highlight the evolution of microstructural alteration throughout the disease progression. The study aims to describe the longitudinal, stage-specific evolution of diffusion tensor imaging parameters in JE.MethodsThis was a retrospective study of 72 serologically established JE patients, determining microstructural alteration in JE in acute (≤7 days) and subacute (8-30 days) phases. The DTI values for ADC, MD, FA, RD, and AD were extracted from bilateral thalami and basal ganglia. The longitudinal changes of the DTI values were determined using linear mixed-effects models with phase, region, and phase × region interaction as fixed effects.ResultsThe most frequent involvement was the thalami compared to the basal ganglia on conventional MRI. Mixed-model effects analysis revealed significant phase-related increases in ADC and MD, while FA and RD demonstrated strong region-specific temporal effects. Significant phase × region interactions were detected for ADC, FA, RD, and AD, suggesting greater temporal variability in the thalamus than the basal ganglia. Post hoc testing confirmed a marked discrepancy between acute and subacute stages, particularly in the thalamus.ConclusionDTI reveals dynamic, region-dependent microstructural evolution in JE. The thalamus is showing the most distinct changes over time. These findings suggest that DTI may provide complementary information regarding disease activity and may be considered a potential imaging marker of disease evolution.
BackgroundParticle therapy involving the optic nerve may cause optic neuropathy. Knowledge of post-treatment imaging findings is important for early detection.PurposeTo investigate optic nerve and peri-optic enhancement following particle therapy for periorbital malignancies.Materials and methodsThis retrospective study included 16 patients with contrast-enhanced MRI after particle therapy (15 proton beam therapy and one heavy-ion radiotherapy), comprising 24 evaluated optic nerve sides. Two experienced neuroradiologists independently reviewed the reference and most recent follow-up MR images, and disagreements were resolved by consensus. Exploratory dose associations were evaluated using side-level logistic generalized estimating equations accounting for within-patient correlation.ResultsGrade 2 enhancement was observed in 7 of 16 patients (43.8%) and 9 of 24 sides (37.5%), involving the optic nerve in 6 sides and the peri-optic region in 7. Among 21 sides in 14 proton-treated patients, optic nerve enhancement was not significantly associated with maximum dose (OR per 10 Gy [RBE], 1.481; 95% CI, 0.883-2.482; p = 0.137) but was nominally associated with BED3 (OR, 1.705; 95% CI, 1.201-2.421; p = 0.003). Peri-optic enhancement was not significantly associated with maximum dose (OR, 1.479; 95% CI, 0.734-2.980; p = 0.274) or BED3 (OR, 1.490; 95% CI, 0.999-2.222; p = 0.051). One patient was clinically diagnosed with RION; no visual symptoms were documented in the remaining 15 patients.ConclusionOptic nerve or peri-optic enhancement may occur after particle therapy, including in patients without documented visual symptoms, and may represent subclinical radiation-related injury or nonspecific post-radiation changes.
BackgroundPostprocedural diffusion-weighted imaging (DWI) lesions are common markers of microembolic injury after coil embolization of unruptured intracranial aneurysms. We evaluated associations of a thrombus-excluded cumulative procedural complexity score with DWI lesion burden and periprocedural neurologic events.MethodsWe retrospectively analyzed 394 patients who underwent elective coil embolization of unruptured intracranial aneurysms between 2021 and 2024. Cumulative procedural complexity was assessed using an exploratory five-domain framework that excluded thrombus-related events. Associations with postprocedural DWI lesion count and periprocedural neurologic events were evaluated using multivariable negative binomial and logistic regression analyses, respectively.ResultsPostprocedural DWI lesions were identified in 160 patients (40.6%), and periprocedural neurologic events occurred in 35 patients (8.9%). Each 1-point increase in the thrombus-excluded cumulative procedural complexity score was associated with a 10% increase in the expected postprocedural DWI lesion count (adjusted IRR, 1.10; 95% CI, 1.02-1.19; p = .015) and 22% higher odds of periprocedural neurologic events (adjusted OR, 1.22; 95% CI, 1.08-1.38; p = .002).ConclusionsA higher thrombus-excluded cumulative procedural complexity score was associated with greater postprocedural DWI lesion burden and higher odds of periprocedural neurologic events. This exploratory, consensus-based framework should be considered hypothesis-generating and requires external validation before clinical application.
BackgroundUp to 50% of Brain metastases (BM) are associated with lung cancer. Different radiologic features such as tumor size, anatomical location and peritumoral edema affect the clinical course. However, their impact on prognosis and survival is controversial.Patients and MethodsA retrospective study of lung cancer patients who underwent surgical resection of solitary BM. Based on pre-operative radiologic features of the BM, the cohort was divided into 3 groups: solid, cystic-necrotic, and purely cystic lesion. Extent of peritumoral edema and the cerebral vascular territory affected were also examined.ResultsThe studied cohort included 89 patients. Following categorization, 24 (27%), 46 (51.6%) and 19 (21.4%) cases were considered solid, cystic-necrotic and purely cystic, respectively. Severity of peritumoral edema (p = 0.019) as well as the vascular territory affected (p = 0.011) were the principal differences between groups. Rate of distal brain recurrence was nearly two-fold higher in the purely cystic subgroup vs. the cystic-necrotic subgroup (p = 0.075). On multivariable analysis, adjusted to vascular territory and edema severity, only purely cystic lesions were significantly associated with increased risk for distal recurrence (HR = 2.92, p = 0.040) and showed a trend towards worse progression-free survival (HR = 2.10, p = 0.089) when compared to solid cases. Overall survival curves showed no significant difference between groups.ConclusionThe radiologic phenotype of BM seems to have limited impact on OS in surgically treated lung cancer patients. Purely cystic BM might be associated with unfavorable risk for distal recurrence. For some outcome parameters, meaningful differences between the 3 radiologic groups were found, suggesting potential clinical implications.
PurposeThis systematic review and meta-analysis evaluates endovascular therapy (EVT) versus best medical treatment (BMT) in pediatric acute ischemic stroke (AIS) due to large-vessel occlusion.MethodsSystematic searches were conducted across PubMed, Cochrane, and Embase, inception July-2025. Comparative studies of EVT versus BMT in pediatric AIS were included. Efficacy outcomes assessed were Modified Rankin Scale (mRS) 0-2, mRS 0-1 and Pediatric Stroke Outcome Measure (PSOM). Safety outcomes included mortality, symptomatic intracranial hemorrhage (sICH), any intracranial hemorrhage (aICH), hospital stay length and need for craniectomy.Results10 studies (n = 20,083) were included. In the primary analysis restricted to confirmed large-vessel occlusion (LVO), EVT was associated with significantly higher odds of achieving a good functional outcome (mRS 0-2: OR 2.08; 95% CI 1.07-4.03) and showed no significant difference in all-cause mortality (OR 2.01; 95% CI 0.34-12.01) compared to BMT. In the all-comers analysis, EVT was associated with higher all-cause mortality (OR 3.00; 95% CI 2.23-4.02) and increased risk of aICH (OR 3.12; 95% CI 1.78-5.47); however, these signals were heavily confounded by baseline stroke severity.ConclusionWhen restricted to confirmed LVO, EVT demonstrates a potential functional benefit over BMT in pediatric AIS. The increased risks of aICH and mortality observed in broader analyses are likely confounded by indication, reflecting the selection of the most severe cases for intervention. Based on GRADE assessments, the certainty of evidence remains very low, highlighting the critical need for prospective studies incorporating standardized reperfusion metrics.
The clinical value of perfusion imaging in arterial ischemic stroke is well established, but its interpretation in cerebral venous sinus thrombosis (CVST) remains less clearly defined. We present a case series of five patients with acute CVST who demonstrated perfusion abnormalities on initial CT perfusion (CTP) or MR perfusion (MRP). The observed findings demonstrated a spectrum of venous hemodynamic patterns. Several patients showed delayed transit metrics, including increased MTT or Tmax, with preserved or increased CBV, suggesting venous congestion or vasogenic edema rather than arterial-type ischemic penumbra. In contrast, one patient demonstrated delayed transit with decreased CBV and CBF, suggesting more advanced venous infarction or tissue-level perfusion failure. One additional patient demonstrated hyperperfusion in a non-territorial distribution, most compatible with ictal or peri-ictal hyperemia rather than a primary venous congestion pattern. Four patients had favorable neurological recovery, whereas one patient had a poor short-term outcome likely driven primarily by large baseline hemorrhage. These cases highlight that perfusion abnormalities in CVST should be interpreted differently from arterial stroke and may be most useful when stratified into venous congestion, venous infarction, and seizure-related hyperperfusion patterns.
Neuroanatomy remains one of the most challenging areas in medical education, including neuroradiology, due to its complexity and limitations of traditional teaching methods. This study proposes a novel approach based on systematic image and video sequences to enhance the presentation, exploration, communication, learning, and teaching of neuroanatomy. Systematic image sequences are ordered sets of spatially and contextually correlated images characterized by five features: anatomical content, parcellation, annotation, location, and dimensionality. Five elementary sequence types are introduced: appearance, contextual, multi-dimensional, dissection, and special, which can be combined into composite (homogeneous/heterogeneous, uni-view/multi-view) sequences. These sequences are presented in interactive, single multi-image, and automated modes, and extended to video formats. The sequences were created using a high-resolution, fully parcellated 3D atlas of the human brain, head, and neck. 12 image sequences (51 images) and two video sequences are presented and discussed, along with references to three major resources of ready-to-use sequences: NOWinBRAIN repository (over 8600 3D neuroimages), ebook Neuroanatomy Made Easy (over 350 sequences), and the latest edition of Gray's Anatomy/Chapter_28. The proposed sequences enhance visualization and understanding of anatomical structures and relationships. Appearance sequences improve recognition through parcellation and labeling, while contextual sequences reveal spatial relationships. Dissection and cortical opening sequences expose otherwise hidden structures, and multi-dimensional sequences bridge 2D radiology with 3D anatomy. Hence, the method elucidates complex anatomical organization, including cortico-vascular relationships, ventricular-venous alignment, and cranial nerve pathways. Overall, systematic image-video sequences provide a conceptually straightforward, easy-to-use, simply integrable, and cost-effective framework enhancing spatial understanding and interpretation, particularly in neuroradiology.
Arteriovenous fistulas (AVFs) involving the inferior petroclival vein (IPCV) are extremely rare and may mimic cavernous sinus (CS) dural arteriovenous fistulas (DAVF) because of shared venous drainage patterns. A 72-year-old man presented with diplopia and left ocular chemosis. Carotid angiography revealed retrograde venous drainage into the superior ophthalmic vein via the inferior petrosal sinus (IPS) and CS. The initial findings suggested a CS-DAVF; however, three-dimensional angiography, including multiplanar reconstruction and maximum intensity projection analyses, identified shunt pouches in the IPCV and anterior condylar vein. Transvenous embolization via the IPS allowed the selective coil embolization of the IPCV shunt pouch while preserving the IPS. The IPCV-AVF resolved completely. Although the anterior condylar vein dural AVF remained, it was classified as Borden type I and was managed conservatively. The present case highlights the importance of detailed three-dimensional angiographic analysis to distinguish IPCV-AVF from CS-DAVF and guide effective treatment.
BackgroundIntracranial arterial stenosis is a major cause of ischemic stroke in Asian populations. High-resolution magnetic resonance imaging (HR-MRI) of the vessel wall is an emerging tool that offers valuable insights.MethodsWe conducted a retrospective study of adult patients (≥18 years) with acute ischemic stroke and M1 MCA stenosis who underwent HR-MRI at the University Medical Center Ho Chi Minh City between January 2019 and May 2025.ResultsSixty-two patients were included (mean age, 56 ± 13 years; male-to-female ratio, 2:1). The average stenosis degree was 66.3 ± 17.5, with severe stenosis in 38.7% of patients. The predominant pattern was eccentric stenosis (80.6%), more frequently observed in older patients. The mean remodeling index was 0.87 ± 0.21, and most cases showed negative remodeling. The majority of lesions at the stenotic site exhibited post-contrast enhancement, most commonly grade 2 enhancement (43.6%). The most frequent cause of stenosis was atherosclerosis (43 cases), followed by dissection (2 cases), Moyamoya disease (1 case), and indeterminate etiology (16 cases). Among infarct-associated atherosclerotic lesions, plaques with intraplaque hemorrhage (58.1%), irregular plaque surface (86.1%), and strong (grade 3) enhancement (46.5%) were observed more frequently than in the small non-infarct-associated incidental group; however, this exploratory comparison was limited by the very small size of the comparator group.ConclusionsHR-MRI of the MCA vessel wall provides detailed information on stenotic lesion characteristics, aiding in the identification of the underlying etiology. These findings highlight the potential role of HR-MRI in stroke diagnosis and risk stratification in Vietnamese patients.
BackgroundArterial calcification is commonly found in patients with cerebrovascular disease and may negatively affect outcomes following endovascular thrombectomy (EVT) for acute ischemic stroke (AIS). This systematic review and meta-analysis aimed to evaluate the impact of intracranial or aortic arch calcification on procedural success and functional outcomes in AIS patients undergoing anterior circulation EVT.MethodsWe systematically searched the PubMed, EMBASE, and Cochrane databases to identify studies comparing EVT outcomes between AIS patients with and without arterial calcification. Outcomes assessed included first-pass effect (FPE), successful reperfusion at the end of the procedure, modified Rankin scale (mRS), mortality, and symptomatic intracerebral hemorrhage (sICH). Risk ratios (RRs) with 95% confidence intervals (CIs) were pooled using random effects models, with heterogeneity evaluated with I2 statistics.ResultsA total of six observational studies were included, with a total of 3834 patients (2303 with calcification and 1531 controls). Arterial calcification was associated with a lower chance of achieving FPE (RR: 0.50, 95% CI: 0.36-0.69, p < 0.001) and successful reperfusion (RR: 0.90, 95% CI: 0.86-0.94, p < 0.001). Patients with calcification had a greater risk of poor outcome (mRS 3-6) (RR: 1.29, 95% CI: 1.16-1.43, p < 0.001), mortality (RR: 1.51, 95% CI: 1.14-2.00, p < 0.001), and sICH (RR: 1.29, 95% CI: 1.16-1.43, p < 0.001). Heterogeneity was low, with I2 ≤ 34%.ConclusionArterial calcification may be indicative of advanced vascular disease, potentially leading to diminished technical success and worse functional outcomes following EVT for AIS. These findings underscore that vascular calcification acts as an associative marker of procedural complexity and advanced vascular disease in EVT candidates.
BackgroundAlzheimer's disease requires early detection for effective intervention with disease-modifying treatments, yet significant implementation barriers persist in clinical practice, including limited computational infrastructure and the gap between research model performance and practical deployment in resource-constrained settings.ObjectivesTo develop and evaluate a computer-aided diagnosis system for classifying cognitive states (AD, MCI, and CN) from structural MRI, with automated preprocessing and cost-effective cloud deployment suitable for resource-constrained healthcare facilities.DesignComputer-aided diagnosis system integrating neural architecture search with serverless cloud infrastructure.MethodsA multi-view MRI analysis model was optimized through neural architecture search, incorporating Universal Inverted Bottleneck blocks and Kolmogorov-Arnold Networks. Automated MRI preprocessing using FSL was deployed through cloud-based serverless functions for scalable image processing. Evaluation used the ADNI dataset (1687 individuals: 368 AD, 625 MCI, and 694 CN). A web application was developed providing patient management, MRI visualization, and automated diagnostic prediction.ResultsThe model achieved 86.7% accuracy and 0.900 AUC in three-class classification with 1.7 million parameters. High specificity was observed across all classes (CN: 91.0%, MCI: 91.8%, AD: 97.3%), with 100% CN-AD specificity ensuring no AD cases were misclassified as cognitively normal. Operational costs were approximately 0.028 USD per diagnosis for typical hospital workloads.ConclusionThis system provides a cost-effective approach for early Alzheimer's diagnosis accessible to resource-constrained environments. Despite challenges in MCI classification, the combination of neural architecture search with serverless deployment demonstrates progress toward clinically deployable automated AD detection. Future work should focus on prospective clinical validation and integration of interpretability features.
Cerebrovascular hemodynamics are increasingly implicated in cognitive aging and mild cognitive impairment (MCI). Transcranial Doppler (TCD) ultrasonography enables noninvasive assessment of intracranial blood flow dynamics. However, longitudinal data in older adults with and without MCI remain limited. This study aimed to longitudinally characterize cerebral hemodynamic and cognitive changes in elderly adults with and without MCI.This prospective cohort study included adults aged ≥60 years enrolled through the CIMVAC registry and evaluated at a dedicated neurological assessment center. Participants underwent standardized clinical evaluation, neuropsychological testing, carotid duplex ultrasonography, and TCD at baseline and two-year follow-up. TCD parameters included peak systolic, end-diastolic, and mean flow velocities, pulsatility index, and resistance index in the middle cerebral arteries, with bilateral values averaged per participant.Ninety-nine participants completed 2-years follow-up. Baseline extracranial atherosclerotic burden was low, with carotid plaque identified in 16.7% of vessels. Over 2 years, plaque prevalence and intima-media thickness increased significantly. TCD demonstrated significant longitudinal increases in pulsatility and resistance indices (both p < 0.001), while flow velocities remained unchanged. Cognitive performance declined modestly, with reductions in MMSE and IADLs scores and increased depressive symptoms. Although patients with MCI exhibited lower cognitive scores and lower baseline flow velocities, no consistent differences in Doppler-derived parameters were observed between MCI subgroups at baseline or follow-up.In elderly adults, TCD primarily reflects age-related changes in cerebrovascular resistance but does not reliably distinguish MCI from normal cognition. Nonetheless, TCD may serve as a complementary, low-cost tool for longitudinal cerebrovascular monitoring, particularly in resource-limited settings.
BackgroundThis study aims to assess whether T2 relaxometry can distinguish tissue characteristics between high-grade gliomas and non-infiltrative lesions.MethodsWe report our initial experience using the Relaxo LNI software to analyze multi-echo T2 relaxometry magnetic resonance imaging in patients with high-grade gliomas. For comparison, peritumoral T2-hyperintense areas in meningiomas and metastases were used as reference regions for vasogenic edema, based on the established concept that these tumor types typically do not infiltrate adjacent tissue. In contrast, peritumoral hyperintensity observed in high-grade gliomas may represent either vasogenic edema or tumor infiltration.ResultsData from 30 patients were analyzed, including 20 with high-grade gliomas and 10 with metastasis or meningiomas. A statistically significant difference was observed in multi-echo T2 relaxation values between the glioma and non-glioma groups (p < 0.05). Mean T2 relaxation times were longer in the high-grade glioma group than in the non-glioma group (p < 0.05). Within the high-grade glioma group, central regions showed significantly longer mean relaxation times than peripheral regions (p < 0.05).ConclusionOur preliminary findings suggest that T2 relaxometry identifies differences in relaxation profiles between tumor tissue and control edema, indicating potential value in detecting variations in peritumoral tissue composition in high-grade gliomas. However, these results are exploratory and hypothesis-generating, lack histopathological validation, and require further investigation to clarify the role of T2 mapping in preoperative planning.
ObjectiveSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been associated with neurological complications beyond respiratory involvement. Although children usually experience mild systemic disease, immune-mediated central nervous system (CNS) disorders have emerged as an important cause of morbidity. Neuroimaging plays a central role in detecting these complications and supporting diagnostic decisions. This study aims to describe neuroimaging patterns in children who developed immune-mediated CNS disorders following SARS-CoV-2 infection.Materials and methodsWe retrospectively reviewed pediatric patients aged 0-18 years with laboratory-confirmed SARS-CoV-2 infection followed at a tertiary pediatric neurology center. Among post-COVID admissions, four patients with severe neurological involvement and characteristic neuroimaging abnormalities were identified. Clinical features, laboratory findings, cerebrospinal fluid analyses, electroencephalography results, and multimodal neuroimaging studies were evaluated.ResultsFour previously healthy male children developed immune-mediated neurological disorders associated with SARS-CoV-2 infection, including febrile infection-related epilepsy syndrome, acute disseminated encephalomyelitis, central nervous system vasculitis, and anti-N-methyl-D-aspartate receptor encephalitis. Brain MRI demonstrated disorder-specific patterns such as cortical diffusion restriction, multifocal demyelinating lesions, inflammatory vasculitic changes, and progressive parenchymal injury. In one patient, serial imaging showed progression from acute inflammation to chronic structural damage. All patients received immunomodulatory therapy, with variable neurological outcomes.ConclusionSARS-CoV-2 infection may trigger immune-mediated CNS disorders in children with distinct neuroimaging features. Recognition of these patterns is essential for early diagnosis, treatment guidance, and prognostic assessment. Neuroimaging also provides insight into the evolution of post-COVID-19 neuroinflammatory injury.
BackgroundCarotid artery calcification represents a common feature of atherosclerotic plaques. However, the geometric relationships of calcific clusters have not been systematically investigated. This study aimed to develop a geometry-based atlas, independent of symptom status, characterizing the three-dimensional properties of calcium clusters within carotid plaques and quantifying population-level distributions and data-driven couplings between size, shape, and density.MethodsStandardized three-dimensional calcium masks of clinical CT scans were analyzed using connected-component labeling. Extracted features included cluster volume, aspect ratio, eccentricity, compactness, and CT attenuation values (mean μ, standard deviation σ). Associations between cluster features were assessed using Spearman correlations with Benjamini-Hochberg false discovery rate correction. Independent associations were determined using partial Spearman correlation and restricted cubic spline regression.ResultsAmong 107 plaques, 149 distinct clusters were identified, most frequently presenting as a single elongated cluster (aspect ratio = 2.23). Independent associations (all p < 0.001) were identified for: eccentricity with μ (ρ = -0.39), volume with μ (ρ = 0.47), compactness with μ (ρ = 0.39), and volume with eccentricity (ρ = 0.82). Multi-cluster plaques exhibited smaller mean cluster volume (76.1 vs 359.5 mm3; p < 0.001) and lower eccentricity (0.5 vs 1.6; p < 0.001) compared with single-cluster plaques.ConclusionCarotid calcification most frequently manifests as a single elongated cluster, with robust couplings between cluster size, shape, and density. These geometric archetypes provide a quantifiable framework for future biomechanical and biological studies of plaque vulnerability.
Treated cerebrospinal fluid-venous fistulas (CVFs) can recur in up to 15% of cases, and they rarely occur at locations remote from the original lesion; the underlying mechanisms remain unclear. We report the case of a male sexagenarian with spontaneous intracranial hypotension (SIH), diffuse spinal nerve root diverticula, and no CVF identified on baseline lateral decubitus CT myelography (CTM). He underwent high-volume epidural and targeted transforaminal blood and fibrin patching with substantial but incomplete symptom relief, followed by transient rebound intracranial hypertension (RIH). Repeat CTM after symptom recurrence demonstrated a new right T5 CVF arising from a remodeled diverticulum and draining into the azygos system. The fistula was successfully treated with transvenous embolization, resulting in sustained clinical and radiological resolution. This case illustrates that in patients with multilevel diverticula, possibly representing connective tissue weakness, post-treatment pressure shifts (including RIH and other causes of episodic cerebrospinal fluid hypertension) may promote the formation or unmasking of CVFs.
BackgroundIschemic stroke, often caused by intracranial atherosclerotic stenosis (ICAS), is a leading cause of disability and death globally. 7T MRI offers improved signal-to-noise ratio (SNR) and contrast, enhancing MRA image quality. This study assessed the accuracy of 7T high-resolution (HR) MRI and time-of-flight MRA (TOF-MRA) in measuring middle cerebral artery (MCA) stenosis compared to digital subtraction angiography (DSA).MethodsIn this prospective observational study, patients, diagnosed with MCA atherosclerotic stenosis, underwent 7T HR-MRI, TOF-MRA and DSA. Spearman correlation analysis was used to assess the linear correlation between HR-MRI, TOF-MRA, and DSA measurements of MCA stenosis. Agreement for stenosis classification data was evaluated using weighted kappa values. Receiver Operating Characteristic (ROC) curves were utilized to predict severe stenosis and occlusion of MCA in HR-MRI and TOF-MRA.ResultsThis study included 86 lesions from 81 patients with MCA atherosclerotic stenosis. The stenosis degree measurements between 7T HR-MRI and DSA indicated a very strong correlation (r = 0.8000; p < .0001). The correlation between 7T TOF-MRA and DSA assessments was high (r = 0.7188; p < .001). A robust correlation between 7T HR-MRI and TOF-MRA evaluations was shown (r = 0.839; p < .0001). 7T TOF-MRA (K = 0.673) demonstrated substantial agreement with DSA measurements, showing slight superiority over HR-MRI (K = 0.589). ROC analysis indicated both 7T HR-MRI and TOF-MRA effectively predicted severe MCA stenosis and occlusion (HR-MRI, AUC: 0.888; TOF-MRA, AUC: 0.878).Conclusions7T HR-MRI and TOF-MRA may emerge as comparable modalities for assessing MCA atherosclerotic stenosis, and HR-MRI allows for precise evaluation through direct visualization of the vessel lumen and plaque.
ObjectivesTo evaluate virtual non-contrast (VNC) accuracy at multiple radiation doses and iodine concentrations in a head CT phantom using dual-energy integrating-detector CT (EID-CT; TwinSpiral DECT) and photon-counting detector CT (PCD-CT).Materials and MethodsA cylindrical head-sized acrylic CT phantom with brain tissue inserts and iodine (0, 43.75, 175, and 350 mg/mL; 87.5 mg/mL was excluded due to beam-hardening artifacts) was scanned three times on each system at 100%, 80%, 75%, 65%, 50%, and 25% of the standard radiation dose to generate mixed and VNC images. Attenuations (HU) were measured in standard and corresponding VNC images; signed and absolute VNC errors were analyzed with two-way ANOVA (dose, iodine) with Tukey post hoc tests (p < .05), using nonparametric alternatives when assumptions were violated. Phantom HU for fat, bone, and white matter at 100% dose on EID-CT were compared with 16 patient scans to confirm realism.ResultsRadiation dose significantly affected VNC errors in both scanners, but only 25% versus 100% dose in PCD-CT was significant after Tukey (p = .0383); no pairwise dose differences were significant in EID-CT (p ≥ .07). Iodine concentration had a stronger effect. In EID-CT, 350 mg/mL differed from 0, 43.75, and 175 mg/mL (p < .001), with errors up to +13.7 ± 1.1 HU. In PCD-CT, 175 and 350 mg/mL differed from 0 mg/mL (p < .05) and from 43.75 mg/mL (p < .001), with a negative bias up to -10.6 ± 1.5 HU.ConclusionsDose reduction had limited impact on VNC accuracy, whereas high iodine (175-350 mg/mL) caused significant errors with opposite signed biases (EID-CT overestimation, PCD-CT underestimation). Both scanners still achieved substantial visual contrast removal.
