多回波快速自旋回波T2 mapping定量技术评价心肌T2值的价值

 目的 探讨多回波快速自旋回波序列(MEFSE)的T₂ mapping定量技术评价左室心肌T₂值的价值。方法 30例健康志愿者,均行3.0T心脏磁共振(CMR)Cine电影、T₂WI序列、MEFSE T₂ mapping序列扫描,依据描述性研究方法,探索MEFSE T₂ mapping序列临床应用的可行性和可重复性,测定感兴趣区T₂值,应用方差分析方法统计分析心肌17节段和不同供血区下有无差异。应用Bland~Altman分析和Pearson相关分析方法研究此技术在不同观察者间的一致性。结果 健康志愿者17节段心肌T₂值不全相等(P＜0.01)。不同冠状动脉供血区T₂值无统计学差异(F=1.656,P=0.192)。左室心肌平均T₂值如下:基底部,(71.6±7.1)ms;中间部,(77.3±9.2) ms;心尖部,(83.0±8.5)ms,差异有统计学意义(F=14.245,P＜0.01)。根据Bland-Altman一致性分析和Pearson相关分析得到参数测量在观察者间具有良好的一致性,95%一致性界限(-6.1,24.8)ms,相关系数r=0.809。结论 CMR MEFSE T₂ mapping定量技术在心脏成像中具有较好的可行性和可重复性。中国健康志愿者中心肌T₂值存在节段性差异。     

A multi-perspective concept mapping study of problems associated with traumatic brain injury

Objective: To develop a model of the problems of persons with traumatic brain injury that includes multiple perspectives as well as the multi-dimensional nature of the phenomena.

Design: Concept mapping, a multi-variate modelling strategy, was employed to produce an exhaustive inventory and concept map of TBI-related problems based on input from patients, family caregivers and professional providers.

Results: The eight-cluster concept map included the following dimensions: social competence, intimacy, behavioural, maturity/independence, neurophysiological, mood, executive functions and non-executive functions.

Conclusions: An underlying two-dimensional conceptual model of TBI problems is proposed with relevance for theory, practice and further research.     

Alterations in midline cortical thickness and gyrification patterns mapped in children with 22q11.2 deletions

The 22q11.2 deletion syndrome (velocardiofacial/DiGeorge syndrome)is a neurogenetic condition associated with visuospatial deficits,as well as elevated rates of attentional disturbance, mood disorder,and psychosis. Previously, we detected pronounced cortical thinningin superior parietal and right parieto-occipital cortices inpatients with this syndrome, regions critical for visuospatialprocessing. Here we applied cortical pattern-matching algorithmsto structural magnetic resonance images obtained from 21 childrenwith confirmed 22q11.2 deletions (ages 8–17) and 13 demographicallymatched comparison subjects, in order to map cortical thicknessacross the medial hemispheric surfaces. In addition, corticalmodels were remeshed in frequency space to compute their surfacecomplexity. Cortical maps revealed a pattern of localized thinningin the ventromedial occipital–temporal cortex, criticalfor visuospatial representation, and the anterior cingulate,a key area for attentional control. However, children with 22q11.2DSshowed significantly increased gyral complexity bilaterallyin occipital cortex. Regional gray matter volumes, particularlyin medial frontal cortex, were strongly correlated with bothverbal and nonverbal cognitive functions. These findings suggestthat aberrant parieto-occipital brain development, as evidencedby both increased complexity and cortical thinning in theseregions, may be a neural substrate for the deficits in visuospatialand numerical understanding characteristic of this syndrome.     

Preservation of Muscular and Elastic Artery Distensibility After an Intercontinental Cryoconserved Exchange: Theoretical Advances in Arterial Homograft Generation and Utilization

While the situation of tissue donation and transplantation differs between Latin American and European countries, a common problem is tissue deficiency. Hence, at present, there is a pressing need to generate alternatives so as to increase the possibilities of obtaining the requested materials. Consequently, it would be of significant interest to establish an intercontinental network for tissue exchange, to improve international cooperation, and to help patients that need tissue transplantation, and to evaluate the feasibility of using an intercontinental network for the exchange of cryopreserved arteries (cryografts), preserving the arterial distensibility and ensuring a reduced native artery–cryograft biomechanical mismatch. Distensibility was studied in ovine arteries divided into three groups: intact (in vivo tests, conscious animals), fresh control (in vitro tests immediately after the artery excision, Uruguay), and cryografts (in vitro tests of cryopreserved-transported-defrosted arteries, Spain). Histological studies were performed so as to analyze changes in the endothelial layer and elastic components. The comparison between fresh control and cryografts showed that neither the cryopreservation nor the exchange network impaired the distensibility, despite the expected histological changes found in the cryografts. The comparison between intact and cryografts showed that the cryografts would be capable of ensuring a reduced biomechanical mismatch. The cryopreservation and the intercontinental network designed for artery exchange preserved the arterial distensibility. It could be possible to transfer cryografts between Latin America and Europe to be used in cardiovascular surgeries and/or for tissue banking reprocessing, with basic biomechanical properties similar to those of the fresh and/or native arteries.