Objective:To investigate the impact of different etiologies on the spatial distribution pattern of infarcts and the mapping pattern of focal symptoms in acute ischemic stroke (AIS) using a population-based standardized spatial analysis of MRI.Methods:This was a cross-sectional study. Clinical [age, sex distribution, admission National Institutes of Health Stroke Scale (NIHSS) score and 90-day modified Rankin Scale (mRS) score at discharge, etc.] and imaging data of 2 610 patients with AIS attending 9 Medical Centers from January 2015 to December 2021 were retrospectively analyzed. All patients were categorized into 1 718 cases of large artery atherosclerosis (LAA) type, 335 cases of cardioembolism (CE) type, and 557 cases of small artery occlusion (SAO) type according to TOAST typing. All patients underwent diffusion-weighted imaging, and the detected infarct lesions were segmented and aligned to the standardized space using artificial intelligence-assisted methods, and the spatial distribution frequency heatmaps of lesion locations in patients with different TOAST subtypes were plotted and compared with each other by χ2 test. Lesion-symptom image brain maps with different clinical symptoms were further plotted, and differences of lesion-symptom image relationships among different TOAST subtypes were observed and compared with each other by interaction effect. Results:In all patients, the favored sites of infarct lesions were the bilateral middle cerebral artery region in the anterior circulation and the occipital and brainstem regions in the posterior circulation. Compared with the LAA type, the CE type lesions were more likely to occur in the anterior cerebral artery region, the occipital lobe, and the cerebellum posterior, while the SAO type lesions were more likely to occur in the perforator artery supply area. The lesion-symptom mapping results showed that AIS patients with infarct lesions in the frontoparieto-temporal region in the presence of a left middle cerebral artery supply had higher admission NIHSS scores and higher discharge 90-day mRS scores for the LAA type than for the CE type( P<0.05); AIS patients with infarcted lesions in the brainstem region and some cerebellar regions in the presence of vertebrobasilar artery supply had higher admission NIHSS scores and higher discharge 90-day mRS scores for the CE type than for the LAA type( P<0.05). Conclusion:At the population level, brain mapping reveals specific infarct distribution patterns and differences in lesion-symptom mapping patterns of different etiologies AIS patients, providing imaging evidence for the understanding of AIS pathogenetic mechanisms and clinical management.

Hepatic stellate cells (HSCs) are the primary fibrogenic cells in the liver, and their activation plays a crucial role in the development and progression of hepatic fibrosis. Here, we report that retinoid X receptor-alpha (RXRα), a unique member of the nuclear receptor superfamily, is a key modulator of HSC activation and liver fibrosis. RXRα exerts its effects by modulating calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ)-mediated activation of AMP-activated protein kinase-alpha (AMPKα). In addition, we demonstrate that K-80003, which binds RXRα by a unique mechanism, effectively suppresses HSC activation, proliferation, and migration, thereby inhibiting liver fibrosis in the CCl₄ and amylin liver NASH (AMLN) diet animal models. The effect is mediated by AMPKα activation, promoting mitophagy in HSCs. Mechanistically, K-80003 activates AMPKα by inducing RXRα to form condensates with CaMKKβ and AMPKα via a two-phase process. The formation of RXRα condensates is driven by its N-terminal intrinsic disorder region and requires phosphorylation by CaMKKβ. Our results reveal a crucial role of RXRα in liver fibrosis regulation through modulating mitochondrial activities in HSCs. Furthermore, they suggest that K-80003 and related RXRα modulators hold promise as therapeutic agents for fibrosis-related diseases.

Objective:To investigate the impact of different etiologies on the spatial distribution pattern of infarcts and the mapping pattern of focal symptoms in acute ischemic stroke (AIS) using a population-based standardized spatial analysis of MRI.Methods:This was a cross-sectional study. Clinical [age, sex distribution, admission National Institutes of Health Stroke Scale (NIHSS) score and 90-day modified Rankin Scale (mRS) score at discharge, etc.] and imaging data of 2 610 patients with AIS attending 9 Medical Centers from January 2015 to December 2021 were retrospectively analyzed. All patients were categorized into 1 718 cases of large artery atherosclerosis (LAA) type, 335 cases of cardioembolism (CE) type, and 557 cases of small artery occlusion (SAO) type according to TOAST typing. All patients underwent diffusion-weighted imaging, and the detected infarct lesions were segmented and aligned to the standardized space using artificial intelligence-assisted methods, and the spatial distribution frequency heatmaps of lesion locations in patients with different TOAST subtypes were plotted and compared with each other by χ2 test. Lesion-symptom image brain maps with different clinical symptoms were further plotted, and differences of lesion-symptom image relationships among different TOAST subtypes were observed and compared with each other by interaction effect. Results:In all patients, the favored sites of infarct lesions were the bilateral middle cerebral artery region in the anterior circulation and the occipital and brainstem regions in the posterior circulation. Compared with the LAA type, the CE type lesions were more likely to occur in the anterior cerebral artery region, the occipital lobe, and the cerebellum posterior, while the SAO type lesions were more likely to occur in the perforator artery supply area. The lesion-symptom mapping results showed that AIS patients with infarct lesions in the frontoparieto-temporal region in the presence of a left middle cerebral artery supply had higher admission NIHSS scores and higher discharge 90-day mRS scores for the LAA type than for the CE type( P<0.05); AIS patients with infarcted lesions in the brainstem region and some cerebellar regions in the presence of vertebrobasilar artery supply had higher admission NIHSS scores and higher discharge 90-day mRS scores for the CE type than for the LAA type( P<0.05). Conclusion:At the population level, brain mapping reveals specific infarct distribution patterns and differences in lesion-symptom mapping patterns of different etiologies AIS patients, providing imaging evidence for the understanding of AIS pathogenetic mechanisms and clinical management.

Intracranial atherosclerotic stenosis (ICAS) is the main cause of patients with stroke in China. How to accurately detect and identify vulnerable plaques through imaging examinations, and strengthen the prediction and prevention of ischemic stroke in patients with ICAS, is a key clinical problem that needs to be solved, and is also a current challenge. With the application of magnetic resonance vascular wall imaging in ICAS, imaging examinations provide useful information on the vascular structure and plaque stability at the stenosis in addition to the degree of stenosis. It has improved the ability to evaluate ICAS and promoted its development towards more accurate diagnosis and treatment.

Objective To analyze the demographic data,CT characteristics,treatment methods and follow-up results of patients with spontaneous isolated dissection of celiac artery(SIDCA)and to explore the selection of treatment strategy for SIDCA.Methods Medical records of 31 patients diagnosed as SIDCA were selected.The patients were divided into 2 groups,symptomatic group and asymptotic group.Demographic data,morbidity season,CT characteristics(type,distance of the entry site from the origin of the artery,dissection length,compression rate of the true lumen,branches involvement,organ ischemia,coexisting vasculopathy),treatment methods,and follow-up results were analyzed.Results Thirty-one patients were identified by CT contrast scan,22 were symptomatic and 9 were asymptomatic.22 patients were first diagnosed in cooler season,compared with 9 patients in warmer season(22 vs 9,Fisher's exact test,P=0.029).The difference between symptomatic and asymptomatic groups about branches involvement in patients was significant(8/14 vs 0/9,Fisher's exact test,P=0.007).Treatment included observation in 24,endovascular intervention in 6 patients and surgical repair in 1 patient.No patient required bowel resection.The mean follow-up period was 13.75 months.Except for 2 patients,the condition of the remaining patients improved or stabilized during follow-up.Conclusion The difference between symptomatic and asymptomatic groups about branches involvement in patients is significant.Initial conservative treatment may be adequate for patients without end organ malperfusion or aneurysm formation or aneurysm rupture in SIDCA.Additionally,during the cooler season,visceral artery should be observed carefully on abdominal contrast CT,especially in the patient with abdominal pain,to avoid misdiagnosis.

Objective:To investigate the relationship between wall shear stress (WSS) and the degree of lumen stenosis and plaque characteristics in patients with atherosclerotic stenosis in the middle brain.Methods:Thirty-four patients with moderate to severe unilateral middle cerebral artery stenosis in Nanjing First Hospital from June 2020 to June 2021 were analyzed retrospectively. All patients underwent routine magnetic resonance imaging and vascular wall imaging to obtain plaque parameters such as plaque area, remodeling mode and remodeling index. Based on magnetic resonance angiography, a computational fluid dynamics model was established to simulate the local hemodynamics near the lesion and quantify WSS. The patients were divided into high WSS group and low WSS group according to the median WSS. The differences of clinical baseline data, degree of lumen stenosis and plaque characteristics between the two groups were compared. Pearson correlation analysis was used to calculate the correlation between WSS and lumen stenosis and plaque characteristics.Results:A total of 34 patients were included in this study, 17 in the high WSS group and 17 in the low WSS group. Compared with the low WSS group, the plasma homocysteine level in the high WSS group was lower [(11.10±4.96) μmol/L vs (16.97±6.98) μmol/L, t=-2.83, P=0.010], the degree of stenosis was lower (0.56±0.05 vs 0.66±0.08, t=-4.54, P<0.001), and the proportion of positive lumen remodeling was higher (12/17 vs 4/17, P=0.015). Pearson correlation analysis showed that the degree of lumen stenosis was negatively correlated with WSS ( r=-0.44, P=0.011), and the plaque area was not correlated with WSS. Conclusions:WSS in middle cerebral artery stenosis is related to the degree of lumen stenosis and the mode of vascular remodeling. Higher WSS has poor stability, but lower WSS is more likely to cause lumen stenosis.

Intracranial atherosclerotic lesions are a common cause of ischemic stroke. Hemodynamics plays an important role in the formation and development of atherosclerosis and the risk assessment of clinical ischemic stroke events. As an evaluation method of cerebral hemodynamics, computational fluid dynamics can intuitively obtain hemodynamic parameters and provide valuable information for clinical diagnosis and treatment. This article reviews the application progress of computational fluid dynamics in evaluating peripheral hemodynamics of intracranial atherosclerotic lesions.

Objective: To evaluate the performance of a convolutional neural network (CNN) model that can automatically detect and classify rib fractures, and output structured reports from computed tomography (CT) images. Materials and Methods: This study included 1079 patients (median age, 55 years; men, 718) from three hospitals, between January 2011 and January 2019, who were divided into a monocentric training set (n = 876; median age, 55 years; men, 582), five multicenter/multiparameter validation sets (n = 173; median age, 59 years; men, 118) with different slice thicknesses and image pixels, and a normal control set (n = 30; median age, 53 years; men, 18). Three classifications (fresh, healing, and old fracture) combined with fracture location (corresponding CT layers) were detected automatically and delivered in a structured report. Precision, recall, and F1-score were selected as metrics to measure the optimum CNN model. Detection/diagnosis time, precision, and sensitivity were employed to compare the diagnostic efficiency of the structured report and that of experienced radiologists. Results: A total of 25054 annotations (fresh fracture, 10089; healing fracture, 10922; old fracture, 4043) were labelled for training (18584) and validation (6470). The detection efficiency was higher for fresh fractures and healing fractures than for old fractures (F1-scores, 0.849, 0.856, 0.770, respectively, p = 0.023 for each), and the robustness of the model was good in the five multicenter/multiparameter validation sets (all mean F1-scores > 0.8 except validation set 5 [512 x 512 pixels; F1-score = 0.757]). The precision of the five radiologists improved from 80.3% to 91.1%, and the sensitivity increased from 62.4% to 86.3% with artificial intelligence-assisted diagnosis. On average, the diagnosis time of the radiologists was reduced by 73.9 seconds. Conclusion Our CNN model for automatic rib fracture detection could assist radiologists in improving diagnostic efficiency, reducing diagnosis time and radiologists’ workload.

Objective To investigate the relationship between vascular remodeling patterns of atherosclerotic middle cerebral artery (MCA) stenosis and plaque enhancement.Methods From August 2015 to June 2016,patients with unilateral symptomatic atherosclerotic MCA stenosis underwent routine MRI and black blood magnetic resonance inaging examinations.The vessel area and lumen area of MCA at the site of atherosclerotic MCA stenosis were measured,and the degree of MCA stenosis and the remodeling index were calculated.Results A total of 33 patients were included.Eleven had obvious plaque enhancement,including 9 positive remodeling and 2 negative remodeling;22 did not have plaque enhancement,including 5 positive remodeling,5 no remodeling,and 12 negative remodeling.The obvious plaque enhancement group was mainly positive remodeling (81.8％ vs.22.7％),and the no obvious enhancement group was mainly negative remodeling (54.5％ vs.18.2％).The difference was statistically significant (P=0.018).Conclusion Plaque enhancement at the site of atherosclerotic MCA stenosis is mainly positive remodeling,which reflects plaque instability.

Objective To investigate the feasibility and application value of the benign and malignant classificational methods of renal occupying CT images based on convolutional neural networks (CNN). Methods An image omics method that can automatically learn the image features and classify CT images was used. Firstly, the CNN model obtained by large-scale natural image training was used to migrate the characteristics of the renal occupancy lesions CT images, and then the fine-tuning of the full connection layer was used to realize the benign and malignant classification of the images. Results The evaluation indexes of the VGG19 model were lower than ResNet50 and Inception V3, and the training result showed obvious overfitting. The accuracy, sensitivity and negative prediction values of the Inception V3 model was 93.8％, 99.5％ and 99.1％, respectively, which were higher than that of the ResNet50 model. Conclusions The benign and malignant classification of renal occupancy lesions CT images using CNN is a reasonable and feasible method, and the fine-tuned Inception V3 model has a better classification performance.