目的探讨心脏磁共振(cardiac magnetic resonance,CMR)在原发性肥厚型心肌病诊断及其分型的临床应用价值。方法回顾性分析2017年至2019年在上海交通大学医学院附属第九人民医院就诊的40例原发性肥厚型心肌病患者的临床资料,所有患者均行...目的探讨心脏磁共振(cardiac magnetic resonance,CMR)在原发性肥厚型心肌病诊断及其分型的临床应用价值。方法回顾性分析2017年至2019年在上海交通大学医学院附属第九人民医院就诊的40例原发性肥厚型心肌病患者的临床资料,所有患者均行CMR检查,采用亮血电影序列、首过灌注序列、延迟增强序列,分析图像质量,观察心肌受累节段,从形态学上对肥厚型心肌病的进行分型,测量心肌厚度、心室容积、射血分数;观察室壁运动和首过灌注情况,评价心肌活性,判断是否存在心肌微循环障碍及纤维化。结果40例患者CMR符合原发性肥厚型心肌病诊断。根据心肌肥厚形态特点,将肥厚型心肌病分为4型:心尖肥厚型心肌病11例、室间隔型19例、向心型4例、心室中部型6例。CMR检查确诊31例患者出现心肌延迟强化,表现为肥厚心肌内斑片样强化,占心肌肥厚患者的77.5%。2例患者发现心尖室壁瘤。结论CMR一站式成像对于诊断原发性肥厚型心肌病有独特作用,多平面电影序列能充分显示肥厚心肌节段、范围,有无流出道梗阻,并且可动态观察室壁运动情况;首过灌注及对比剂延迟强化能提示心肌活性,判断心肌纤维化,对临床治疗和预后有指导意义。展开更多
Background With conventional imaging methods only the morphous of the visual nerve fiber bundles can be demonstrated, while the earlier period functional changes can not be demonstrated. We hypothesized that diffusion...Background With conventional imaging methods only the morphous of the visual nerve fiber bundles can be demonstrated, while the earlier period functional changes can not be demonstrated. We hypothesized that diffusion tensor imaging （DTI） would demonstrated the whole optic never fiber bundle and visual pathway and the earlier period functional changes. The purpose of the present study was to evaluate the application of DTI technique in the demonstration of the whole optic never fiber bundle and visual pathway, and the influence of orbital tumors on them. Methods GE 1.5T signa HD MR System, and the software package DTV2 were adopted. The total 45 subjects were enrolled, including 15 volunteers and 30 patients. All patients had ocular proptosis from minor to major. Seven patients had visual acuity decrescence. Results The nerve fiber bundles, e.g. optic chiasma, optic tract and optic radiation in posterior visual pathway were well demonstrated in all cases. Wherein, the intact whole visual pathway fiber bundles were clearly revealed in 10 volunteers and 17 patients, and optic nerve was not wholly revealed in the rest of the subjects. Shift of optic nerve caused by compression and partial deformation were seen in 7 patients with orbital tumor, in 6 of 7 patients, DTI displayed significant abscise and deformation of visual nerve. Chi-square test indicated significant correlation between visual acuity decrescence and DTI visual nerve non-display. Conclusions Visual nerve fiber bundles and the whole visual pathway were visualized in most of patients with DTI. It might be an effective method of providing imaging evidence for visual nerve fiber earlier period functional changes, and laid a foundation for the study in other cranial nerves. Chin Med J 2009; 122（2）： 178-182展开更多
Background Recognizing renal vascular variants preoperatively is important in order to avoid vascular complications during surgery. This study aimed to investigate the renal vascular variants with dual-energy computed...Background Recognizing renal vascular variants preoperatively is important in order to avoid vascular complications during surgery. This study aimed to investigate the renal vascular variants with dual-energy computed tomography （DECT） angiography to provide valuable information for surgery. Methods A total of 378 patients underwent DECT. The number, size, course and relationships of the renal vessels were retrospectively observed from the scans. Anomalies of renal arteries and veins were recorded and classified. Multiplanar reformations （MPR）, maximum intensity projections （MIP）, and volume renderings （VR） were used for analysis. Results In 378 patients （756 kidneys）, renal artery variations were discovered and recorded in 123 kidneys （16.3%, 123/756） of 106 patients （28.0%, 106/378）. Type IB （early branches of the only one main renal artery） and IC （accessory renal artery with only one main renal artery） were found most frequently with an incidence of 11.4% （43/378） and 14.5% （55/378）. The incidence of renal artery variations in the left kidney was not statistically different than in the right kidney （12.4% vs. 11.1%）. The incidence of renal vein variations was detected in 104 patients （27.5%, 104/378）. The incidence of venous variants in the right kidney was higher than in the left kidney （20.1% vs. 7.4%）, but left renal vein variations were more complex. Variants of the left renal vein were detected in 28 patients including type 1 （circumaortic left renal vein） in eight cases, type 2 （retroaortic left renal vein） in seven cases, type 3 （abnormal reflux） in six cases, type 4 （late venous confluence of left renal vein） in five cases, and type 5 （rare type） in two cases. The frequency of left renal vein variation associated with the left renal accessory artery was significantly higher than with early branches of the left renal artery （P=0.037）. Conclusions The renal vascular variants are rather common and complex. DECT angiography can demonstrate the precise anatomy of the renal vessels, which is a benefit for renal transplantation or other renal operations展开更多
In this article, a novel cooperative wireless localization scheme based on information fusion is proposed. The scheme combines large-scale arrival time and small-scale distance measurements obtained from the next-gene...In this article, a novel cooperative wireless localization scheme based on information fusion is proposed. The scheme combines large-scale arrival time and small-scale distance measurements obtained from the next-generation converged networks. The maximum likelihood （ML） estimate of the terminal＇s position is derived with closed-form solution, and the Cramer-Rao lower bound （CRLB） of the estimate error is investigated. Both theoretical analysis and simulation results verify that the proposed localization scheme can significantly enhance the location precision. Moreover, the mean square error of position estimate approximates the CRLB when the number of reference stations increases, which indicates that the proposed ML estimator is asymptotically efficient.展开更多
To mitigate inter-cell interference in 3G evolution systems, a novel inter-cell interference coordination scheme called soft fractional frequency reuse is proposed in this article, which enables to improve the data ra...To mitigate inter-cell interference in 3G evolution systems, a novel inter-cell interference coordination scheme called soft fractional frequency reuse is proposed in this article, which enables to improve the data rate in cell-edge. On this basis, an inter-cell power control is presented for the inter-cell interference coordination, and the inter-cell balanced signal to interference plus noise ratio （SINR） among users is established for power allocation, which enables mitigation of inter-cell interference. Especially, the power control is based on a novel exponential kernel arithmetic kernel equations. Numerical results show that the proposed rate compared to the existing power control algorithms. equation at higher convergence speed than the traditional scheme improves the throughput and reduces the blocking展开更多
文摘目的探讨心脏磁共振(cardiac magnetic resonance,CMR)在原发性肥厚型心肌病诊断及其分型的临床应用价值。方法回顾性分析2017年至2019年在上海交通大学医学院附属第九人民医院就诊的40例原发性肥厚型心肌病患者的临床资料,所有患者均行CMR检查,采用亮血电影序列、首过灌注序列、延迟增强序列,分析图像质量,观察心肌受累节段,从形态学上对肥厚型心肌病的进行分型,测量心肌厚度、心室容积、射血分数;观察室壁运动和首过灌注情况,评价心肌活性,判断是否存在心肌微循环障碍及纤维化。结果40例患者CMR符合原发性肥厚型心肌病诊断。根据心肌肥厚形态特点,将肥厚型心肌病分为4型:心尖肥厚型心肌病11例、室间隔型19例、向心型4例、心室中部型6例。CMR检查确诊31例患者出现心肌延迟强化,表现为肥厚心肌内斑片样强化,占心肌肥厚患者的77.5%。2例患者发现心尖室壁瘤。结论CMR一站式成像对于诊断原发性肥厚型心肌病有独特作用,多平面电影序列能充分显示肥厚心肌节段、范围,有无流出道梗阻,并且可动态观察室壁运动情况;首过灌注及对比剂延迟强化能提示心肌活性,判断心肌纤维化,对临床治疗和预后有指导意义。
文摘Background With conventional imaging methods only the morphous of the visual nerve fiber bundles can be demonstrated, while the earlier period functional changes can not be demonstrated. We hypothesized that diffusion tensor imaging （DTI） would demonstrated the whole optic never fiber bundle and visual pathway and the earlier period functional changes. The purpose of the present study was to evaluate the application of DTI technique in the demonstration of the whole optic never fiber bundle and visual pathway, and the influence of orbital tumors on them. Methods GE 1.5T signa HD MR System, and the software package DTV2 were adopted. The total 45 subjects were enrolled, including 15 volunteers and 30 patients. All patients had ocular proptosis from minor to major. Seven patients had visual acuity decrescence. Results The nerve fiber bundles, e.g. optic chiasma, optic tract and optic radiation in posterior visual pathway were well demonstrated in all cases. Wherein, the intact whole visual pathway fiber bundles were clearly revealed in 10 volunteers and 17 patients, and optic nerve was not wholly revealed in the rest of the subjects. Shift of optic nerve caused by compression and partial deformation were seen in 7 patients with orbital tumor, in 6 of 7 patients, DTI displayed significant abscise and deformation of visual nerve. Chi-square test indicated significant correlation between visual acuity decrescence and DTI visual nerve non-display. Conclusions Visual nerve fiber bundles and the whole visual pathway were visualized in most of patients with DTI. It might be an effective method of providing imaging evidence for visual nerve fiber earlier period functional changes, and laid a foundation for the study in other cranial nerves. Chin Med J 2009; 122（2）： 178-182
文摘Background Recognizing renal vascular variants preoperatively is important in order to avoid vascular complications during surgery. This study aimed to investigate the renal vascular variants with dual-energy computed tomography （DECT） angiography to provide valuable information for surgery. Methods A total of 378 patients underwent DECT. The number, size, course and relationships of the renal vessels were retrospectively observed from the scans. Anomalies of renal arteries and veins were recorded and classified. Multiplanar reformations （MPR）, maximum intensity projections （MIP）, and volume renderings （VR） were used for analysis. Results In 378 patients （756 kidneys）, renal artery variations were discovered and recorded in 123 kidneys （16.3%, 123/756） of 106 patients （28.0%, 106/378）. Type IB （early branches of the only one main renal artery） and IC （accessory renal artery with only one main renal artery） were found most frequently with an incidence of 11.4% （43/378） and 14.5% （55/378）. The incidence of renal artery variations in the left kidney was not statistically different than in the right kidney （12.4% vs. 11.1%）. The incidence of renal vein variations was detected in 104 patients （27.5%, 104/378）. The incidence of venous variants in the right kidney was higher than in the left kidney （20.1% vs. 7.4%）, but left renal vein variations were more complex. Variants of the left renal vein were detected in 28 patients including type 1 （circumaortic left renal vein） in eight cases, type 2 （retroaortic left renal vein） in seven cases, type 3 （abnormal reflux） in six cases, type 4 （late venous confluence of left renal vein） in five cases, and type 5 （rare type） in two cases. The frequency of left renal vein variation associated with the left renal accessory artery was significantly higher than with early branches of the left renal artery （P=0.037）. Conclusions The renal vascular variants are rather common and complex. DECT angiography can demonstrate the precise anatomy of the renal vessels, which is a benefit for renal transplantation or other renal operations
基金supported by the Program for New Century Excellent Talents in University (NCET-05-0116)the Hi-Tech Research and Development Program of China (2006AA01Z283, 2007AA01Z261)+1 种基金the National Natural Science Foundation of China (60702051)the Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP-20070013028)
文摘In this article, a novel cooperative wireless localization scheme based on information fusion is proposed. The scheme combines large-scale arrival time and small-scale distance measurements obtained from the next-generation converged networks. The maximum likelihood （ML） estimate of the terminal＇s position is derived with closed-form solution, and the Cramer-Rao lower bound （CRLB） of the estimate error is investigated. Both theoretical analysis and simulation results verify that the proposed localization scheme can significantly enhance the location precision. Moreover, the mean square error of position estimate approximates the CRLB when the number of reference stations increases, which indicates that the proposed ML estimator is asymptotically efficient.
基金supported by Sino-Swedish Project (2008DFA12110)Key Project of BMSTC (D08080100620802)+1 种基金the National Natural Science Foundation of China (60872048)National Science and Technology Special Project ‘Group Cell’ (2009ZX03003-011)
文摘To mitigate inter-cell interference in 3G evolution systems, a novel inter-cell interference coordination scheme called soft fractional frequency reuse is proposed in this article, which enables to improve the data rate in cell-edge. On this basis, an inter-cell power control is presented for the inter-cell interference coordination, and the inter-cell balanced signal to interference plus noise ratio （SINR） among users is established for power allocation, which enables mitigation of inter-cell interference. Especially, the power control is based on a novel exponential kernel arithmetic kernel equations. Numerical results show that the proposed rate compared to the existing power control algorithms. equation at higher convergence speed than the traditional scheme improves the throughput and reduces the blocking
