BACKGROUND AND PURPOSE:Although high-resolution conebeam CT (HR-CBCT) is used for immediate evaluation of stent apposition, studies using this technique to evaluate flow diverter (FD) endothelialization during follow-up are limited. The study aims to investigate the potential of HR-CBCT in assessing FD endothelialization and identify factors influencing poor endothelialization. MATERIALS AND METHODS:The clinical and imaging data of patients with unruptured intracranial aneurysms (UIAs) treated by FDs from March 2019 to October 2023 were retrospectively analyzed. HR-CBCT was used for immediate evaluation of stent apposition, and FD endothelialization at 3, 6, and 12 months postimplantation was evaluated by using HR-CBCT and digital subtraction angiography. Multivariate logistic regression analysis was used to identify factors associated with poor endothelialization. RESULTS:Among 402 FDs implanted for 446 aneurysms in 378 patients, 41 showed incomplete stent apposition (ISA) in postimplantation HR-CBCT scans. The aneurysm-occlusion rate at 12 months postimplantation was 84.8% (378/446), with 8.7% (35/402) of the FDs exhibiting in-stent stenosis (ISS). At 12 months postimplantation, 343 (85.1%) FDs showed good endothelialization, while 59 (14.9%) exhibited poor endothelialization. Multivariate logistic regression analysis identified age ≥60 years (OR = 2.209; 95% CI, 1.053-4.635; P = .04), a large aneurysm lumen inflow angle (OR = 1.102; 95% CI, 1.071-1.135; P < .001), parent artery excessive tortuosity (OR = 9.402; 95% CI, 1.141-77.479; P = .04), and ISA (OR = 10.967; 95% CI, 4.290-28.035; P < .001) as independent risk factors for poor endothelialization. CONCLUSIONS:HR-CBCT can accurately evaluate FD endothelialization and ISS of UIAs after FD implantation. Age ≥60 years, a large aneurysm lumen inflow angle, parent artery excessive tortuosity, and ISA are independent risk factors for poor endothelialization.

ObjectivesTo develop and validate a prediction model that integrates radiomics-habitat and deep learning (DL) features derived from vessel wall MRI (VWI) for evaluating unruptured intracranial aneurysms (UIAs) instability.MethodsFirst, from January 2022 to January 2024, 519 consecutive patients with suspected UIAs were screened. After applying exclusion criteria, 293 patients with 312 UIAs were ultimately enrolled. 197 UIAs were stable (from 188 patients) and 115 UIAs were unstable (from 105 patients). Second, aneurysm regions were segmented, and K-means clustering was used to partition them into three habitat subregions. Third, a Transformer-based fusion model for assessing UIA instability was developed to integrate radiomics-habitat features, DL features, and clinical variables. Model performance was evaluated using AUC, calibration curves, and clinical gain metrics, including Net Reclassification Index (NRI) and Integrated Discrimination Improvement (IDI). Last, SHAP (SHapley Additive exPlanations) was applied to enhance model interpretability.ResultsThe Transformer-based fusion model assessing UIA instability exhibited superior performance (validation AUC = 0.844) compared with the optimal radiomics-habitat model (AUC = 0.721) and the top-performing DL model (DenseNet169, AUC = 0.816). The model demonstrated superior clinical utility, with an NRI of 0.282 and an IDI of 0.558 compared to the Radiomics-Habitat model. Decision curve analysis showed a high net clinical benefit across a range of threshold probabilities.ConclusionThe Transformer-based fusion model provides an exploratory risk-assessment model and has the potential to assist in clinical decision-making.

The rupture of carotid atherosclerotic plaque is one of the major causes of ischemic stroke. While stenosis severity has traditionally guided risk stratification, it remains an insufficient predictor for vulnerability assessment. This review synthesizes current knowledge towards a comprehensive framework for assessing carotid plaque vulnerability by integrating in vivo imaging, hemodynamic analysis, and mechanobiology. High-resolution, multi-contrast magnetic resonance imaging enables detailed characterization of plaque components, including the fibrous cap, lipid-rich necrotic core, and intraplaque hemorrhage, which are more relevant to patient symptoms than the current clinical primary criterion, luminal stenosis. These morphological features serve as essential inputs for computational models that quantify biomechanical stresses. Hemodynamic analysis reveals that low wall shear stress promotes plaque initiation and progression, whereas elevated plaque structural stress, often concentrated in the thin fibrous cap, is closely associated with rupture. Mechanosensitive ion channels transduce these mechanical stimuli into cellular signals mediating endothelial responses to shear stress and smooth muscle cell adaptation to structural stress. Emerging evidence implicates Piezo channels in inflammatory cell function and vascular remodeling pertinent to atherosclerosis. Despite these advances, large-scale prospective studies validating the predictive value of advanced imaging, biomechanical, and biological metrics remain lacking. Future directions include developing tailored therapeutic strategies targeting mechanosensitive ion channels, clarifying their molecular mechanisms in vascular pathobiology, and employing advanced imaging and computational tools for patient-specific risk assessment. This integrative approach holds promise for transitioning from stenosis-based evaluation towards mechanobiology-informed precision medicine in atherosclerosis management.

BACKGROUND AND PURPOSE:Endovascular treatment of unruptured intracranial aneurysms (UIAs) carries a potential risk of infarction due to new embolic events caused by small artery occlusion. Parent artery plaque enhancement (PAPE) and aneurysm wall enhancement (AWE) on vessel wall imaging are imaging phenotypes with multiple potential pathophysiological substrates, including but not limited to atherosclerosis. While these imaging features may reflect underlying vascular vulnerability, their relationship with postprocedural microembolic events remains unclear. The aim of this study is to investigate the relationship between PAPE or AWE on vessel wall imaging (VWI) and new microembolic events on diffusion-weighted imaging (DWI) after endovascular treatment of UIAs. MATERIALS AND METHODS:A total of 159 patients with 159 UIAs who underwent endovascular treatment and had preoperative MRI (including VWI and DWI) and postoperative MRI (including DWI) were prospective enrolled in this study. The PAPE, quantitative parent artery plaque enhancement ratio (PER), AWE, aneurysm enhancement ratio (AER), and new microembolic events were evaluated. Univariate and multivariate logistic regression analyses identified parameters associated to microembolic events. RESULTS:Among 159 patients with 159 UIAs, 57 patients with non-microemboli events and 102 patients with microemboli events were included in this study. Microembolic event patients had higher rates of PAPE (68.6% vs 14.0%; P < 0.001) and AWE (63.7% vs 38.6%; P =0.02), as well as greater PER (median [IQR]: 1.2 [0.5-1.6] vs 0.3 [0.2-0.4], P < 0.001) and AER (1.0 [0.4-1.2] vs 0.6 [0.3-1.1], P =0.01), compared to non-microembolic event patients. In multivariate analysis, PAPE, AWE, and PER were independent factors associated with microemboli events (OR=3.87 for PAPE [95% CI, 1.33-11.24], P=0.01; OR=3.45 for AWE [95% CI, 1.43-8.32], P=0.01; and OR=5.54 for PER [95% CI, 2.09-14.64], P< 0.01). CONCLUSIONS:Parent artery plaque enhancement and aneurysm wall enhancement are correlated with an elevated risk of microembolic events after endovascular treatment of UIAs.

Incomplete stent apposition (ISA) of intracranial stents is recognized as a significant issue in aneurysm treatment leading to in-stent thrombosis and aneurysm recurrence. Traditional imaging techniques like DSA have limitations in accurately assessing stent apposition. This study aimed to explore the efficacy of optical coherence tomography (OCT) in the detection of ISA after stent-assisted coiling (SAC) and its impact on stent endothelialization and aneurysm healing in a porcine model. Twelve healthy minipigs with surgically established common carotid artery sidewall aneurysm were utilized and treated with SAC. DSA and OCT were used immediately post-procedure and during follow-ups at 4 and 12 weeks to assess aneurysm occlusion and stent apposition. Histopathology ultimately assessed stent endothelialization and aneurysm healing. ISA distance, measured by OCT, was analyzed using logistic regression to predict the association between ISA severity and stent endothelialization outcome. OCT detected ISA sites (n = 30) in all subjects at the aneurysm neck, stent ends, and locally in the stent, with a mean ISA distance of 639.65 ± 146.82 µm immediately after the procedure. One experimental pig developed in-stent occlusion after 4 weeks, resulting in death. OCT detected residual ISAs in 54.2

BACKGROUND AND PURPOSE:The wall instability of unruptured intracranial aneurysms (UIAs) is associated with aneurysm growth or rupture. The wall shear stress (WSS) of 4D-flow-MRI can indicate hemodynamic abnormalities on the aneurysm wall. Aneurysm wall enhancement (AWE) of vessel wall MRI (VWI) and volume transfer constant (Ktrans) of dynamic contrast-enhanced MRI (DCE-MRI) can indicate inflammation and permeability changes of the unstable aneurysm wall. We hypothesize that the WSS of UIAs is not only associated with AWE and Ktrans but also with the risk of growth or rupture derived from the ELAPSS or PHASES scores of the aneurysm. MATERIALS AND METHODS:A cross-sectional retrospective analysis was performed on patients with UIAs who underwent 3.0 T VWI, DCE-MRI, and 4D-flow-MRI in our hospital from January 2018 to October 2023. AWE, Ktrans, and WSS were obtained by VWI, DCE-MRI, and 4D-flow MRI, respectively. AWE pattern (AWEP) and wall enhancement index (WEI) were used to evaluate AWE. 3- and 5-year aneurysm growth risk and 5-year rupture risk were predicted based on ELAPSS and PHASES scores, respectively. Correlations between parameters were assessed using Spearman's correlation coefficient or logistic regression. RESULTS:Ninety-six aneurysms in 78 patients (53 women) were included in the study. WSS differed across AWEP subgroups (p < 0.001). WSS was negatively correlated with AWEP, WEI, and Ktrans (rs = -0.35, rs = -0.44, and rs = -0.25; p < 0.001). Multiple logistic regression indicated that decreased WSS was associated with higher odds of AWE (OR: 0.65, 95 % CI: 0.48-0.87). WSS was negatively correlated with the 3- and 5-year growth risk and the 5-year risk of rupture (rs = -0.47, rs = -0.44, and rs = -0.50; p < 0.001). CONCLUSION:WSS on 4D-flow-MRI of aneurysms is inversely associated with AWEP, WEI, and Ktrans and growth and rupture risk. The decrease in WSS on 4D-flow-MRI may provide valuable information for assessing aneurysm wall instability.

To comprehensively investigate the potential temporal dynamic and static abnormalities of spontaneous brain activity (SBA) in left temporal lobe epilepsy (LTLE) and right temporal lobe epilepsy (RTLE) and to detect whether these alterations correlate with cognition. Twelve SBA metrics, including ALFF, dALFF, fALFF, dfALFF, ReHo, dReHo, DC, dDC, GSCorr, dGSCorr, VMHC, and dVMHC, in 46 LTLE patients, 43 RTLE patients, and 53 healthy volunteers were compared in the voxel-wise analysis. Correlation analyses between metrics in regions showing statistic differences and epilepsy duration, epilepsy severity, and cognition scores were also performed. Compared with the healthy volunteers, the alteration of SBA was identified both in LTLE and RTLE patients. The ALFF, fALFF, and dALFF values in LTLE, as well as the fALFF values in RTLE, increased in the bilateral thalamus, basal ganglia, mesial temporal lobe, cerebellum, and vermis. Increased dfALFF in the bilateral basal ganglia, increased ReHo and dReHo in the bilateral thalamus in the LTLE group, increased ALFF and dALFF in the pons, and increased ReHo and dReHo in the right hippocampus in the RTLE group were also detected. However, the majority of deactivation clusters were in the ipsilateral lateral temporal lobe. For LTLE, the fALFF, DC, dDC, and GSCorr values in the left lateral temporal lobe and the ReHo and VMHC values in the bilateral lateral temporal lobe all decreased. For RTLE, the ALFF, fALFF, dfALFF, ReHo, dReHo, and DC values in the right lateral temporal lobe and the VMHC values in the bilateral lateral temporal lobe all decreased. Moreover, for both the LTLE and RTLE groups, the dVMHC values decreased in the calcarine cortex. The most significant difference between LTLE and RTLE was the higher activation in the cerebellum of the LTLE group. The alterations of many SBA metrics were correlated with cognition and epilepsy duration. The patterns of change in SBA abnormalities in the LTLE and RTLE patients were generally similar. The integrated application of temporal dynamic and static SBA metrics might aid in the investigation of the propagation and suppression pathways of seizure activity as well as the cognitive impairment mechanisms in TLE.

ObjectiveCervical artery dissection (CAD) is one of the major causes of stroke and most commonly occurs at the site of the extracranial internal carotid artery (ICA). This study aimed to assess the value of routine brain MRI, clinical information, and high-resolution, multi-contrast vessel wall MR imaging (hrVWI) for the timely detection of ICA dissection.MethodsA total of 105 patients with CAD and 105 without CAD were recruited for this study. The lesion type in the patients was determined based on images from different modalities, including brain MRI, magnetic resonance angiography (MRA), computed tomography angiography (CTA), digital subtraction angiography (DSA), ultrasonography, and hrVWI and clinical information. Each lesion was reviewed to determine the type following a stepwise procedure by referring to (1) brain MRI only; (2) brain MRI and clinical information; (3) hrVWI only; and (4) hrVWI, CTA, DSA, and clinical information.ResultsTypical clinical presentations of patients with potential CAD include headache, neck pain, and/or Horner's syndrome. Representative imaging signs in the brain MRI included a crescentic or circular iso- or hyperintensity around the lumen, a curvilinear and isointense line crossing the lumen, or aneurysmal vessel dilation. Based on brain MRI alone, 54.3% (57/105) of the patients with CAD were correctly classified, and the accuracy increased to 73.3% (77/105) when clinical information was combined (P < 0.001) with high specificity and low sensitivity. Further analysis showed that hrVWI had the superior capability in detecting CAD, with a sensitivity and a specificity of 95.1% and 97.0%, respectively.ConclusionThe combination of brain MRI and clinical information could be used for the diagnosis of CAD; however, hrVWI should be sought for uncertain cases.

Purpose: The purpose of this study was to evaluate the effects of increasing zone II resuscitative endovascular balloon occlusion of the aorta (REBOA) occlusion times on physiological, end-organ and inflammatory responses in rabbits to assess the safe aortic occlusion time in a normovolemic rabbit model. Methods: The zone ll aorta was occluded with a balloon in 32 rabbits (8 animals each for 15, 30, 60, and 90 min). 8 rabbits served as a con-trol. ELISAs were used to examine the serum levels of ALT, AST, Cr, BUN, MDA, SOD, IL-8, IL-6, and TNF-a; HE staining was used to identify the morphological changes in the kidney; RT-PCR was used to detect the mRNA levels of IL-6, IL-8, TNF-a and NF-kB in the kidney and uterus; and Western blotting was used to measure the protein expression levels of IL-6, IL-8, TNF-a and NF-kB in the kidney and uterus. Results: Plasma concentrations of liver markers, kidney markers, inflammatory factors and oxidative stress indicators were significantly increased at the end of reperfusion in the 30 min, 60 min and 90 min groups. Damage to the kidney occurred in the 30 min, 60 min and 90 min groups. The mRNA and protein expression levels of IL-6, IL-8, TNF-a and NF-kB in the kidney and uterus were significantly increased at the end of reperfusion in the 30 min group, and as the time of occlusion extended, these levels continued to increase. Conclusion: Activation of systemic inflammation and ischaemia-reperfusion injury of end-organs occurred when the occlusion time reached 30 min. Therefore, 15 min should be regarded as a safe period of REBOA in zone II.

Aim: To evaluate the safety and efficacy of balloon occlusion at the Zone II aorta for the management of morbidly adherent placenta.Methods: From September 2015 to October 2018, a total of 80 consecutive patients who were prenatally diagnosed with morbidly adherent placenta were assigned into two groups: the balloon occlusion group (n=40) and the non-balloon occlusion group (n=40). The intraoperative estimated blood loss, blood transfusion, urine output, serum creatinine (Scr), blood urea nitrogen (BUN) and hysterectomy rate were recorded and compared between the two groups.Results: The estimated blood loss in the balloon occlusion group was significantly lower than that in the non-balloon occlusion group (811.75±299.93 ml vs 1529.75±808.01 ml, P<0.001). The median amount of packed RBCs transfused in the balloon occlusion group and non-balloon occlusion group was 0 U and 2 U, respectively (P=0.001). The women in the former group had a lower blood transfusion rate than those in the latter group (30% vs 57.5%, P=0.013). Hysterectomy occurred in none in the balloon occlusion group but in 6 patients in the non-balloon occlusion group (P=0.011).Conclusion: The middle abdominal aorta (Zone II) is not a forbidden zone for occlusion as long as the single occlusion time is limited to 15 mins. Balloon occlusion at the Zone II aorta can effectively reduce blood loss, transfusion requirements and hysterectomy rates in patients with morbidly adherent placenta.

目的 分析肝脏血管肉瘤(HA)的CT、MRI表现以及临床和病理特点,以提高诊断准确率,并寻找最优影像检查方案.资料与方法 回顾性分析经病理证实的13例HA的临床、病理资料和影像学特征,包括病灶分布、数目、大小、边界、密度/信号、表观扩散系数(ADC)、标准摄取值(SUV)、强化方式、有无转移等.结果 11例HA有转移灶,常见转移部位包括肺、骨、软组织、脾脏.8例为肝内多发病灶,数目均多于10个并弥漫分布.CT平扫90％(54/60)的病灶呈低密度.MRI平扫病灶边界显示清晰,呈长T1长T2信号.11例肿块样病灶信号不均,可见短T1、短T2、更长T2信号,但仅40％(8/20)的结节样病灶信号不均.典型HA增强的特征为动脉期周边和(或)中心欠规则斑片状强化,门静脉及延迟期呈不完全性充填式强化,且强化程度稍减低.结论 HA的CT和MRI表现具有一定的特征性,结合临床资料可提高诊断准确率.

BackgroundThis study aims to explore the utility of whole-lesion apparent diffusion coefficient (ADC) histogram analysis for differentiating nasopharyngeal lymphoma (NPL) from nasopharyngeal carcinoma (NPC) following readout-segmented echo-planar diffusion-weighted imaging (RESOLVE sequence).MethodsThirty-eight patients with NPL and 62 patients with NPC, who received routine head-and-neck MRI and RESOLVE (b-value: 0 and 1,000 s/mm2) examinations, were retrospectively evaluated as derivation cohort (February 2015 to August 2018); another 23 patients were analyzed as validation cohort (September 2018 to December 2019). The RESOLVE data were obtained from the MAGNETOM Skyra 3T MR system (Siemens Healthcare, Erlangen, Germany). Fifteen parameters derived from the whole-lesion histogram analysis (ADCmean, variance, skewness, kurtosis, ADC1, ADC10, ADC20, ADC30, ADC40, ADC50, ADC60, ADC70, ADC80, ADC90, and ADC99) were calculated for each patient. Then, statistical analyses were performed between the two groups to determine the statistical significance of each histogram parameter. A receiver operating characteristic curve (ROC) analysis was conducted to assess the diagnostic performance of each histogram parameter for distinguishing NPL from NPC and further tested in the validation cohort; calibration of the selected parameter was tested with Hosmer–Lemeshow test.ResultsNPL exhibited significantly lower ADCmean, variance, ADC1, ADC10, ADC20, ADC30, ADC40, ADC50, ADC60, ADC70, ADC80, ADC90 and ADC99, when compared to NPC (all, P < 0.05), while no significant differences were found on skewness and kurtosis. Furthermore, ADC99 revealed the highest diagnostic efficiency, followed by ADC10 and ADC20. Optimal diagnostic performance (AUC = 0.790, sensitivity = 91.9%, and specificity = 63.2%) could be achieved when setting ADC99 = 1,485.0 × 10−6 mm2/s as the threshold value. The predictive performance was maintained in the validation cohort (AUC = 0.817, sensitivity = 94.6%, and specificity = 56.2%)ConclusionWhole-lesion ADC histograms based on RESOLVE are effective in differentiating NPC from NPL.

Objectives: To investigate the predictive factors for successful recanalization based on digital subtraction angiography and three-dimensional T1W sampling perfection with application-optimized contrasts using different flip angle evolutions (3D T1-SPACE) high-resolution magnetic resonance imaging (MRI) signal features. Methods: Consecutive internal carotid artery occlusion cases with ipsilateral ischemic stroke refractory to therapy who visited our institution between February 2017 and August 2020 were retrospectively analyzed. Epidemiology, symptomatology, imaging morphology on angiography and MRI, peri-procedural complications, technical success rate, and follow-up results were summarized. Factors related to technical success were analyzed using univariate and multivariate analyses. Results: In total, 75 cases (53 men, mean age 57.51 ± 9.71 years) were included. The total successful recanalization rate was 72.00% (54/75), with a complication rate of 13.33% (9/75). Through multivariate analysis, first ischemic stroke in <3 months (OR: 2.57; 95% CI: 1.13–4.58), tapered stump (OR: 4.31; 95% CI: 1.37–13.55), reversed flow of the ophthalmic artery (OR: 2.99; 95% CI: 1.06–8.49), high intraluminal signal on unenhanced T1-SPACE sequence (OR: 16.15; 95% CI: 3.40–76.72), no vessel wall collapse (OR: 17.00; 95% CI: 3.57–81.02), short occlusion length (OR: 9.87; 95% CI: 2.09–46.64), and primary occlusion site at the cervical internal carotid artery (OR: 8.42; 95% CI: 1.04–68.19) were associated with successful recanalization. Conclusion: Besides traditional features such as short ischemic event time, tapered stump, and distal ICA reconstitution by the ophthalmic artery, our study demonstrates that luminal and mural changes determined by 3D SPACE high-resolution MRI could also predict successful endovascular recanalization. Endovascular recanalization for non-acute internal carotid artery occlusion is feasible, but prudent case selection is mandatory considering the high periprocedural complication rate.