Background:Hemorrhagic transformation (HT) is a common and severe complication after endovascular treatment (EVT), especially the symptomatic intracerebral hemorrhage (sICH). This study aimed to explore the quantitative diagnostic value of multiphase computed tomography (CT) angiography (mCTA) in predicting HT and sICH in patients with anterior circulation acute ischemic stroke (AIS) after EVT. Methods:We retrospectively collected data of patients with anterior circulation AIS from Tianjin Huanhu Hospital from April 2020 to December 2023. We assessed the arterial collateral circulation (ACC), superficial venous drainage scores (SVS), and deep venous drainage scores (DVS) based on mCTA. SVS1, SVS2, and SVS3, as well as DVS1, DVS2, and DVS3, represented SVS and DVS in the arterial, venous, and late venous phases, respectively. Patients were divided into HT and non-HT groups based on the presence of an intracranial hemorrhage on a follow-up non-contrast CT. We conducted a subgroup analysis of HT patients, dividing them into sICH and asymptomatic intracerebral hemorrhage (aICH) subgroups. We analyzed and compared the clinical variables, ACC, SVS, and DVS in the non-HT and HT groups, as well as in the sICH and aICH subgroups. Multiparameter predictive models of HT and sICH were established using ACC (Model-HT1 and Model-sICH1), SVS and DVS (Model-HT2 and Model-sICH2), and comprehensive parameters (Model-HT3 and Model-sICH3). The performance of predictive models was evaluated and compared using the receiver operating characteristic (ROC) curve and the Delong test. Results:Finally, 127 patients were included, and 46 developed HT. The HT group had a higher ratio of poor ACC than the non-HT group (97.83% vs. 81.48%, P=0.010). A lower SVS1, SVS2, and SVS3 were observed in the HT group compared with the non-HT group (all P<0.05). For the subgroup analysis of HT patients, 14 had sICH, all these patients had poor ACC. A lower SVS1, SVS3, DVS1, and DVS2 were observed in the sICH subgroup than in the aICH subgroup {2 [1, 3] vs. 3 [2, 4], P=0.018; 8 [7, 8] vs. 8 [8, 8], P=0.014; 1 [0.75, 1] vs. 1 [1, 2], P=0.025; and 2 [1, 2] vs. 2 [2, 2], P=0.047}. In Model-HT1 and Model-HT3, ACC was the independent predictor for HT [odds ratio (OR), 13.924; 95% confidence interval (CI): 1.671-115.991; P<0.05 and OR, 9.141; 95% CI: 1.149-72.723; P<0.05]. In Model-sICH2 and Model-sICH3, DVS2 was the independent predictor for sICH (OR, 0.1; 95% CI: 0.018-0.567; P<0.05 and OR, 0.1; 95% CI: 0.018-0.567; P<0.05). The ROC showed that Model-HT3 and Model-sICH2 improved predictive efficacy [area under curve (AUC): 0.789; 95% CI: 0.707-0.856; and 0.828; 95% CI: 0.688-0.893, respectively]. Conclusions:The ACC, SVS, and DVS based on mCTA were valuable for predicting the risk of HT and sICH after EVT, the combination of multiple parameters can improve the predictive efficacy.

While deep learning models have achieved remarkable diagnostic accuracy in medical imaging, their inherent “black box” nature severely impedes clinical adoption due to a lack of transparency and trust. Current eXplainable AI (XAI) methods, such as saliency maps, offer low-level feature attribution but fail to provide clinically meaningful reasoning. State-of-the-art vision-language models trained end-to-end on image-report pairs often learn to exploit superficial correlations from noisy data, generating plausible but clinically vacuous explanations. To address this critical gap, we propose K-Distill-XAI, a novel teacher-student framework that decouples visual feature learning from high-level clinical reasoning. We first train a domain-expert “teacher” Large Language Model (LLM) on a vast corpus of biomedical literature to generate canonical, text-based clinical rationales. Subsequently, we train a multimodal “student” vision-language model using a cross-modal knowledge distillation objective, compelling it to generate explanations that are semantically aligned with the teacher's expert reasoning. Extensive experiments on the public MIMIC-CXR dataset demonstrate the superiority of our approach. K-Distill-XAI significantly outperforms state-of-the-art baselines in clinical accuracy, achieving an 8% relative improvement in CheXbert F1 score for report generation. Furthermore, this distillation process also boosts classification performance and yields state-of-the-art micro-averaged AUC across 14 clinical conditions.

Background:The early postoperative period is critical for patients who have undergone renal transplantation. This study aimed to quantify cortical perfusion in renal allografts during this period using arterial spin labeling (ASL) magnetic resonance imaging (MRI). Methods:Between May and December 2014, ASL MRI was performed on 53 patients with renal allografts who were 2 to 4 weeks post-transplantation, as well as on 20 healthy volunteers. Recipients were stratified into two groups according to estimated glomerular filtration rate (eGFR): those with good allograft function (eGFR ≥60 mL/min/1.73 m2), and those with impaired allograft function (eGFR <60 mL/min/1.73 m2). Renal blood flow (RBF) values were compared across healthy controls and the two recipient groups. The correlation between RBF and eGFR was also evaluated. Results:Mean cortical RBF was 389.9±61.2 mL/100 g/min in healthy controls, 295.0±67.9 mL/100 g/min in recipients with good allograft function, and 195.5±88.9 mL/100 g/min in recipients with impaired allograft function. Statistically significant differences in cortical RBF were observed among the three groups (P<0.001). A moderate positive correlation between eGFR and cortical RBF was identified among renal allograft recipients (R=0.62, P<0.01). Conclusions:Renal cortical perfusion in allografts during the early postoperative period was significantly reduced compared to healthy controls, particularly in cases of impaired allograft function. ASL MRI demonstrates potential as a non-contrast imaging modality for quantifying renal cortical perfusion in the post-transplant setting.

Background:A comprehensive assessment of collateral status can yield profound insights into the ischemic mechanism in patients experiencing acute ischemic stroke. This study aims to investigate whether time-variant and tissue-level collateral characteristics may serve as predictors for functional outcomes in patients undergoing endovascular thrombectomy (EVT) through the application of machine learning (ML) algorithms, and to stratify postoperative neurological recovery of these patients. Methods:In this retrospective study, 128 acute ischemic stroke patients characterized by anterior large-vessel occlusion and received EVT between May 2020 and December 2022 were enrolled. These patients underwent multiphase computed tomography (CT) angiography (mCTA) and CT perfusion (CTP). The time-variant collateral score was defined as the Collateral Score on Color-Coded summation maps (CSCC) of mCTA. The hypoperfusion intensity ratio (HIR) was calculated from CTP data. The data were split into training and test sets in a ratio of 7:3, and univariable and multivariable regression analyses were employed for feature selection. For ML analyses, logistic regression (LR), support vector machine (SVM), random forest (RF), decision tree (DT), and eXtreme gradient boosting (XGBoost) algorithms were utilized. The receiver operating characteristic (ROC) curve and decision curve were employed for performance evaluation. The mixed effect model was established to estimate the impact of collateral stratification on the postoperative National Institutes of Health Stroke Scale (NIHSS). Results:Age [odds ratio (OR) =1.073; 95% confidence interval (CI): 1.008, 1.154; P=0.040], Alberta Stroke Program Early CT Score (ASPECTS) (OR =0.742; 95% CI: 0.546, 0.975; P=0.040), CSCC (OR =0.468; 95% CI: 0.213, 0.953; P=0.044), and HIR (OR =56.666; 95% CI: 3.843, 1,156.959; P=0.005) were significantly associated with good outcome in training set. By utilizing these four selected features, the RF algorithm achieved the best performance and the highest clinical suitability in predicting good clinical outcomes, with an area under the ROC curve (AUC) of 0.964 (95% CI: 0.902, 0.992) and 0.837 (95% CI: 0.684, 0.935) in training set and testing set, respectively. The Shapley Additive exPlanations (SHAP) analysis revealed that HIR was the most significant variable in predicting clinical outcomes. Fixed effects and group × time interaction effects [all P<0.01 at all time points (TPs)] were acquired in HIR stratification. HIR enabled better stratification and prediction of patients' postoperative NIHSS [Akaike information criterion (AIC): HIR =4,599.577 and CSCC =4,648.707]. Conclusions:RF model, which has been trained on time-variant and tissue-level collaterals, is capable of accurately predicting the clinical outcomes of patients undergoing EVT. Stratifying patients based on HIR may yield valuable insights into predicting trends in the potential postoperative neurological recovery.

Background Dual-energy CT (DECT) provides several novel methods to assess thrombus perviousness. We aimed to evaluate whether the novel thrombus perviousness measured with DECT is associated with improved recanalisation and better functional outcomes in acute ischaemic stroke (AIS) patients with endovascular thrombectomy (EVT).Methods 108 AIS patients with middle cerebral artery occlusion who underwent DECT angiography on admission and received EVT treatment between April 2020 and September 2023 were retrospectively analysed. Thrombus attenuation increase (TAI) was evaluated on routine CT angiography and non-contrast CT, and DECT quantitative parameters of thrombus, including iodine concentration (IC) and normalised IC (NIC) were measured. Multivariable logistic regression analysis was used to evaluate the association of thrombus characteristics with arterial occlusive lesion scale and 90-day modified Rankin Scale.Results NIC was significantly associated with successful recanalisation (OR 1.372 (95% CI 1.194 to 1.625); p<0.001) and good functional outcome (OR 1.252 (95% CI 1.114 to 1.446); p<0.001). NIC yielded higher performance, with area under curve (AUC) of 0.789 and 0.740, in the prediction of recanalisation and functional outcome than TAI (AUCs=0.635 and 0.592). Compared with low-level NIC thrombus, high-level NIC was associated with 11.4 and 15.4 times higher likelihood of successful recanalisation and good functional outcome. Moreover, NIC was a significant indicator to differentiate large artery atherosclerosis from cardioembolism stroke with high specificity and positive predictive value.Conclusions Higher DECT-derived NIC is associated with increased odds of successful recanalisation and good functional outcome for EVT patients, and it yielded higher prediction performance than TAI.

BACKGROUND Intracranial tuberculoma is a rare and serious type of tuberculosis, which mostly occurs in the frontoparietal and cerebellar hemispheres, with predominance in the gray-white matter junction area, while tuberculomas only in the cistern are extremely rare with only a few reported cases in the literature. We describe a unique case of isolated tuberculoma in the suprasellar cistern, with only right ocular motility disorder and upper eyelid ptosis. CASE SUMMARY A 5-year-old boy without any medical history presented with right ocular motility disorder and upper eyelid ptosis one month ago. He had no history of fever, headache, vomiting, convulsions, or limb weakness. Neurological examination showed right third cranial nerve palsy with restrictions of eye movements and ptosis, pupil dilation and negative light reflex. Imaging suggested a space-occupying lesion in the suprasellar cistern with calcification and ring-enhancement. Moreover, no Mycobacterium tuberculosis was found in cerebrospinal fluid by polymerase chain reaction (PCR). The lesion was initially diagnosed as a tumor, while postoperative pathology combined with PCR indicated tuberculoma. The patient continued postoperative anti-tuberculosis treatment. At present, the patient's condition is stable and the symptoms are partially relieved compared with those before surgery. CONCLUSION This case confirmed that isolated intracranial tuberculoma can occur in the suprasellar cistern. Therefore, for space-occupying lesions in the suprasellar cistern, tuberculoma should be included in the differential diagnosis even if there is no history or indication of tuberculosis infection.

Objectives: This study aims to evaluate the application value of computed tomography perfusion (CTP) imaging in patients with posterior circulation cerebral infarction in the hyperacute phase. Methods: The changes in CTP parameters, such as time to peak (TTP), mean transfer time (MTT), cerebral blood flow (CBF) and the cerebral blood volume (CBV) of ischemic region, as well as the ischemic penumbra, infarction core at the affected side and normal brain tissue at the uninjured side, of 168 patients with suspected posterior circulation acute ischemic stroke were analyzed. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of each parameter map of CTP in displaying the cerebral infarction size in each part of the posterior circulation were evaluated. Results: The CTP results revealed that CBF and CBV in the infarction area significantly decreased, and MTT and TTP in the blood supply area of cerebellum, thalamus and posterior cerebral artery (PCA) were significantly delayed. These were statistically different from those in the surrounding penumbra and normal brain tissue (P < 0.05). Furthermore, the CBF of the penumbra in each part slightly decreased, and the delay of MTT and TTP was statistically different from that in normal brains (P < 0.05). The CBV of the penumbra in the pons, midbrain and thalamus decreased, which was statistically different from that in normal brain tissue and simple cerebral ischemia tissue (P < 0.05). The changes in CBF and MTT of the simple cerebral ischemia in each part, and TTP, except for the cerebellum, were statistically different from those of cerebral infarction and normal brain tissue (P < 0.05). The total sensitivity, specificity and accuracy for the posterior circulation cerebral infarction was 77.2%, 98.6% and 94.9%, respectively, according to the CTP evaluation. Conclusion: The CTP parameter map can reflect the difference between an ischemic penumbra and an infraction core in the posterior circulation. It has high sensitivity, specificity and accuracy in the CTP evaluation of posterior circulation cerebral infarctions.

BACKGROUND:Mitochondrial encephalomyopathy (ME) is a multisystem metabolic disease that primarily affects the central nervous system and skeletal muscle. It is caused by mutations in mitochondrial or nuclear DNA, resulting in abnormal mitochondrial structure and function and insufficient ATP synthesis. The most common subtype is mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episode (MELAS) syndrome. In recent years, reports of MELAS syndrome have increased but familial cases are rare.CASE SUMMARY:We report a case of familial MELAS syndrome. Cases 2 and 3 are sisters and case 1 is their nephew. All are short in stature and showed stroke-like episodes with rapid onset and no obvious symptoms such as paroxysmal headache, aphasia, or blurred vision. After admission, blood lactate levels were significantly higher than normal. The patients underwent magnetic resonance imaging of the head. Cases 1 and 2 were considered to have ME, whereas case 3 was considered to have a space-occupying lesion in the left temporal lobe. Pathological evaluation showed no obvious tumor cells in the brain lesions of case 3. Muscle biopsy or genetic test results were consistent with ME. The patients were diagnosed with MELAS syndrome and their symptoms improved with intravenous infusions of coenzyme Q10, coenzyme A, vitamin B, and vitamin C. At the 6 mo follow-up, there was no recurrence or progression.CONCLUSION:When a patient has MELAS syndrome, familial MELAS syndrome should be considered if related family members have similar symptoms.

目的 运用倾向性评分匹配(PSM)评价CT漩涡征预测自发性脑出血(sICH)病人早期血肿扩大(HE)价值.方法 回顾性选取2015年1月—2020年2月首诊sICH病人271例,其中男162例,女109例,年龄17～92岁,平均(59.24±16.8)岁.所有病人均于发病后6 h内和24 h内完成初次和二次CT平扫检查.根据病人有无早期HE分为HE组(72例)和非HE组(199例).由2名放射科医师各自独立分析横断面CT平扫漩涡征的表现.采用独立样本t检验或Mann-Whitney U检验比较2组间的计量资料,采用χ2检验比较2组间的计数资料,采用kappa一致性检验分析2名医生对漩涡征评估的一致性.采用Logistic回归分析预测早期HE发生的危险因素.使用PSM将2组病人配对,比较2组病人PSM匹配前后漩涡征对早期HE的预测价值.结果 HE组高血压病史、入院收缩压、初始血肿体积及漩涡征阳性比例均高于非HE组,入院格拉斯哥昏迷评分(GCS)低于非HE组(均P<0.05).2名医师对漩涡征的评估一致性较好(kappa=0.905).Logistic回归分析显示,较高的入院收缩压和初始血肿体积、较低的入院GCS评分及漩涡征阳性是预测早期HE的独立危险因素(均P<0.05).PSM匹配后单因素分析显示HE组病人漩涡征阳性比例高于非HE组(P<0.05).结论 使用PSM方法在均衡变量、减少偏倚后评估漩涡征预测sICH病人早期HE更为准确,临床医师可根据CT平扫漩涡征的出现对有早期HE风险的sICH病人采取及时有效的治疗措施,可减轻病人的不良预后.

目的 探究CT血管成像(CTA)动脉管壁及管腔特征在预测颈动脉内膜剥脱(CEA)术后再梗死的诊断价值.方法 收集183例行CEA的患者,均进行术前及术后CTA检查,术后行MRI检查.根据术后MRI是否出现新发梗死,分为再梗死组和非梗死组.比较两组的术前及术后的术侧颈动脉特征.结果 再梗死组术后颈内动脉颈段管腔横径大于非再梗死组;再梗死组术后动脉皮瓣阳性多于非再梗死组.结论 CEA术后颈段管腔横径及术后是否存在动脉皮瓣与术后出现再梗死存在明显相关;对于预测术后发生再狭窄具有一定的诊断价值.

Introduction This study aims to investigate the reduction of radiation dose in cerebral computed tomography (CT) perfusion by lower low-tube current. Material and methods Two hundred patients, who underwent cerebral non-contrast CT and CT perfusion, were randomized to four groups according to tube current and contrast media (CM) concentration: group A (60 mAs, 320 mg I/ml), group B (60 mAs, 370 mg I/ml), group C (100 mAs, 320 mg I/ml), and group D (100 mAs, 370 mg I/ml). Among these four groups, the CT dose index (CTDIvol), dose length product (DLP) and effective dose (ED) were calculated. The quantitative image comparison included maximum enhancement, noise, signal-to-noise ratio (SNR), cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) from five regions of interests (ROIs). Results Ranging from 100 mAs to 60 mAs, groups A and B achieved 40% lower CTDIvol, DLP and ED, compared with groups C and D. Both the maximum enhancement and noise of all ROIs were higher in groups A and B than in groups C and D (p < 0.05). The CBV values were higher in groups B and D than in groups A and C (p < 0.05). The image quality (IQ) of each group of perfusion maps met the requirements for imaging diagnosis. Conclusions The reduction in tube current from 100 mAs to 60 mAs for cerebral CT perfusion led to a 40% reduction in radiation dose without sacrificing image quality.

Introduction: Due to its rarity and the lack of animal models for this disease, the etiology of bronchial artery aneurysm (BAA) is poorly understood. Aim: To investigate the effect of transcatheter artery embolization (TAE) with coils, spherical polyvinyl alcohol (PVA), and gel foam in patients with BAA. Material and methods: From June 2015 to November 2018, 5 patients diagnosed with BAA with massive hemoptysis after undergoing bronchial arteriography and receiving TAE therapy in the Department of Interventional Radiology were enrolled in this study. Post-embolization angiography was used to demonstrate total occlusion of the BAAs and bronchiectatic engorged vessels. The patients' follow-up was conducted 1-16 months after TAE. Results: All 5 patients were cured by the TAE treatment, during which PVA, coils, and gel foam were applied. The patients also received successful TAE via a microcatheter. Hemoptysis disappeared in all patients. No special or severe complications occurred, and no patient experienced a recurrence during the follow-up. Conclusions: Overall, TAE is the best choice for patients with hemoptysis and BAA due to its effectivity and reliability. Thorough and complete embolization of the bleeding arteries is the key to successful treatment. Though PVA and coils are the most common materials for embolization, gel foam strips can also be applied. Summary Transcatheter artery embolization is a treatment with minimal invasiveness and high effectiveness for patients with bronchial artery aneurysm. Polyvinyl alcohol, gel foam, and coils are good choices for embolization, which is a new method combining a variety of materials and successfully replacing the use of the traditional method in these cases.

急性缺血性卒中是严重危害人类生命健康的主要疾病之一,因此早期诊断治疗至关重要.多模式CT主要包括CT平扫(NCCT)、CT血管造影(CTA)和CT灌注(CTP),能够在早期缺血性改变、出血性转化、血管闭塞、侧支循环及缺血半暗带等方面提供重要信息,从而快速准确的为患者提供一站式服务,指导患者筛选并制定治疗策略.

Objective To evaluate the diagnostic value of CT perfusion （CTP） for posterior circulation cerebral ischemia and hyperacute phase of cerebral infarction.Methods CTP was performed in 184 patients with suspected posterior circulation acute ischemic stroke,and diffusion weighted imaging （DWI） of MRI was performed 24-72 hours after onset.According to the characteristics of various perfusion parameters,the perfusion defect area in

脑CT灌注成像(CTP)已成为评价急性缺血性脑卒中(AIS)和血管痉挛的主要影像技术,CTP数据的漫长采集时间及多次复查导致辐射剂量增加,因此低辐射剂量CTP日益受到重视.降低管电流、降低管电压、优化图像采样频率以及迭代重建(IR)技术的应用均能够达到降低辐射剂量而不降低CTP影像质量的目的 .而多种低剂量技术相结合能够进一步降低辐射剂量.重建算法的改进仍处于研究阶段,有可能使CTP的辐射剂量降至更低的水平,本文对低辐射剂量脑CT灌注技术进展进行综述.

Background and Purpose: Early studies have indicated that the cortico-rubro-spinal tracts play important roles in motor dysfunction after stroke. However, the differential involvement of the rubral branches in capsular and pontine stroke, and their associations with the motor impairment are still unknown. Methods: The present study recruited 144 chronic stroke patients and 91 normal controls (NC) from three hospitals, including 102 cases with capsular stroke (CS) and 42 cases with pontine stroke (PS). The rubral branches, including bilateral corticorubral tracts (CRT), dentatorubral tracts (DRT), and rubrospinal tracts (RST), and the cortico-spinal tract (CST) were reconstructed based on the dataset of the Human Connectome Project. Group differences in diffusion scalars of each rubral branch were compared, and the associations between the diffusion measures of rubral branches and the Fugl-Meyer assessment (FMA) scores were tested. Results: The bilateral CRT of the CS cases showed significantly lower factional anisotropy (FA) than in the NC. The bilateral DRT of the PS cases had lower FA than in the NC. Both CS and PS cases had significantly lower FA of the bilateral RST than the NC. Besides, the stroke patients demonstrated significantly lower FA in bilateral CSTs than the NC. Partial correlation analysis identified significantly positive correlations between the FA of the ipsilesional and CRT and the FMA scores in the CS group, and significantly positive correlations between the FA of the RST bilaterally and the FMA scores in the CS and PS groups. Furthermore, the association between RST integrity and FMA scores still survived after controlling for the effect of the CST. Finally, multiple regression modelling found that rubral tract FA explained 39.2% of the variance in FMA scores for CS patients, and 48.8% of the variance in FMA scores for PS patients. Conclusions: The bilateral rubral branches were differentially involved in the chronic capsular and pontine stroke, and the impairment severity of each rubral branch was dependent on lesion locations. The integrity of the rubral branches is related to motor impairment in both the chronic capsular and pontine stroke.

目的 探讨Rathke囊肿的CT与MRI影像学特征,以提高临床诊断的准确率.方法 回顾性分析本院2003年7月～2013年6月间经手术及病理证实的15例Rathke囊肿的CT及MRI资料.着重分析肿瘤的影像学表现.结果 T1高信号、T2等信号4例;T1等信号、T2等信号2例;T1高信号、T2低信号1例;其余8例T1低信号8例,T1等信号3例;4例见囊内漂浮结节影,增强扫描结节无强化,4例见病囊壁轻度强化.结论 Rathke囊肿囊液密度和信号变化多样,但结合临床和影像学表现对其中多数病例可做出正确诊断.