Functional anatomy of interhemispheric cortical connections in the human brain

Interhemsipheric interaction between the human cerebral hemispheres is served by abundant white-matter fibres in the human corpus callosum (CC). Damage to these fibres has notable behavioural and cognitive sequelae that depend on the exact location of the fibre loss. Until now, correlations between fibre loss and neurological disorders have been limited to post-mortem studies. Here we used probabilistic diffusion magnetic resonance imaging tractography to produce a two-dimensional map of the CC in the mid-sagittal plane. We observed an antero-posterior topography of interhemispheric tracts within the CC, consistent with our current neuroanatomical understanding of post-mortem studies in human. Callosal tract to the left and right hemispheres had comparable volume. Gender, a factor that is often reported to affect CC shape and geometry, also had no effect on the volume of the tracts. Our map showed high consistency across individuals. We propose that this map might be useful in the study of the effects of damage to human CC in neurodegenerative and cognitive disorders.     

人支气管永生化HBE细胞形态计量学分析

目的:探索人支气管永生化HBE细胞超微结构的三维形态结构特征并与人肺腺癌A549细胞进行比较分析。方法:按常规方法制备HBE细胞与A549细胞的透射电镜样品。用Image-ProPlus图像分析软件设计网格测试系统,应用体视学原理和方法,分别测算HBE细胞和A549细胞核的体视学参数包括核体密度(VVn)、核表面积密度(SVn)、核表面积与体积比(RSVn)、核数密度(NVn)、核平均体积(vn)、核平均表面积(sn)和核浆比(Rnp);核仁的体视学参数包括核仁体密度(VVnu)、核仁表面积密度(SVnu)、核仁表面积与体积比(RSVnu)、核仁数密度(NVnu)、核仁平均体积(vnu)、核仁平均表面积(snu)等共13种体视学参数的数值。结果:①HBE细胞核平均体积(vn)和核平均表面积(sn)分别为206.74μm3和184.75μm2,明显小于A549细胞;②HBE细胞核及核仁的表面积与体积比(RSVn)分别为0.9192和2.3536,均大于A549细胞;③HBE细胞核浆比为0.3829,小于A549细胞。结论:HBE细胞核及核仁的形态与肺腺癌A549细胞有差异,其核和核仁的表面积、体积及形态大小均小于A549细胞。     

微栓子阳性动脉硬化性脑梗死患者的临床特点以及微栓子的转归

目的 比较经颅多普勒微栓子监测有、无微栓子信号的颅内大动脉狭窄所致急性脑梗死患者的临床特点,观察微栓子信号的转归.方法 收集存在颅内大动脉狭窄的发病7 d内的急性脑梗死患者,在人院第1天和第7天进行经颅多普勒监测相应的狭窄动脉半小时以及磁共振弥散加权成像检查.确定有无微栓子信号,判断新发梗死灶的数目及分布.详细记录所有临床特点,美国国立卫生院神经功能缺损评分（NIHSS）,用药情况.结果 共收集资料齐全的31例患者,其中12例患者存在微栓子信号.存在微栓子信号的患者NIHSS低于无微栓子信号的患者[（3.83±3.16）分比（7.00±3.93）分,P=0.026];平均年龄亦有低于无微栓子信号患者的倾向[（60.17±18.91）岁比（68.79±11.44）岁,P=0.174];女性患者存在微栓子信号的比例偏高（6/12比3/19,P=0.056）;存在微栓子信号的患者磁共振弥散加权成像上存在多发性梗死灶的比例高（6/12比4/15,P=0.093）.结论 存在微栓子信号的大动脉狭窄患者发生脑梗死的年龄偏早,而卒中严重程度相对较轻.存在微栓子信号的患者磁共振弥散加权成像上病灶多为多发性梗死.卒中发生后微栓子信号可能随时间延长和抗血小板药物的治疗而减少或消失.     

基于CT影像的人体心脏三维重构

三维重构是研究心脏血流机理及特性等问题的有效手段,本文基于CT断层扫描数据,利用Mimics处理工具对心脏进行三维重构,并对左心室优化模型进行偏差分析,优化改变了重构模型的粗糙度,对左心室结构的影响较小为后续探究心脏内部血流模式及特性、血液生理学参数异变和组织结构病变提供了基础研究。     

基于卷积神经网络和Transformer的肝脏CT图像分割方法

针对现有的卷积神经网络在肝脏图像分割上精度较低的问题,提出了一种以U-Net网络模型为基础的分割算法。将多头自注意力机制引入到U-Net网络的跳跃连接中,在编码器部分使用空洞卷积,采用混合损失函数从而提高分割精度。在LITS数据集上通过实验结果表明,利用本文方法进行肝脏分割与传统U-Net方法相比Dice系数提升3.3%,平均交并比提升了2.4%,平均像素准确率提升了3.66%。     

医学图像增强方法综述

医学图像增强的目的是通过图像增强的方法得到优化的医学图像,以帮助医生从图像中获得更多细节信息,进一步做出更加客观的诊断及制定更全面的治疗方案,在一定程度上可提高临床诊断的准确性。本文首先归纳总结当前应用较为广泛的医学图像增强处理技术,包括传统的图像增强方法、改进的图像增强方法、融合的图像增强方法以及深度学习方法,然后对这些方法的原理、优缺点加以分析和总结。最后指出无论是传统方法还是现代图像增强方法,都应在最大限度保留其优势的情况下进行融合,取长补短,注重简单化和时效性,使提高图像的视觉质量同时更具有实用性。     

结直肠癌肝转移预测及预后的影像组学综述

结直肠癌在国内外都是高发病率和高死亡率的肿瘤疾病,肝脏是结直肠癌血行转移最主要的靶器官,尽早准确地预测结直肠癌肝转移的发生以及监测患者治疗的预后反应,对患者的诊断和治疗尤为关键。新兴的影像组学为精准预测结直肠癌肝转移以及评估预后提供新的可能。对现有的结直肠癌肝转移影像组学研究进行综述,首先介绍结直肠癌肝转移研究的临床意义以及现有研究存在的缺陷,然后阐述结直肠癌肝转移影像组学的分析流程,接着对结直肠癌肝转移影像组学的4个研究方向展开综述,包括肝转移病理生长模式预测、隐匿性肝转移预测、肝转移疗效预后评估、肝转移患者生存期预后评估;阐明各个方向的最新研究进展及存在的缺陷性;最后对结直肠癌肝转移影像组学的未来发展趋势进行展望。     

浅析数字化影像在放射治疗质量保证中的应用

通过各种KV级、MV级实时数字化影像和三维重建影像在放疗质量保证中的应用,为放疗射野中心及治疗范围的验证,摆位精度校正和放疗设备和物理特性检查方面提供了有效的手段．使得放射治疗的质量和精度都得到很大提高。     

Relationship between traditional Chinese medicine syndrome differentiation and imaging characterization to the radiosensitivity of nasopharyngeal carcinoma

Background and Objective: Traditional Chinese medicine (TCM) is a well established and time-honored practice in China, employing syndrome differentiation as a basis for the treatment of disease. According to different TCM syndrome typing findings, combining modern medical methods with TCM approaches can improve the quality of life and comprehensive effect on patients with nasopharyngeal carcinoma (NPC). This study investigated the relationship between TCM syndrome typing and imaging characterization to radi...     

Diffusion tensor imaging detects axonal injury and demyelination in the spinal cord and cranial nerves of a murine model of globoid cell leukodystrophy

Globoid cell leukodystrophy is an inherited neurodegenerative disorder caused by a deficiency of the lysosomal enzyme galactosylceramidase. In both human patients and the authentic murine Twitcher model, pathological findings include demyelination as well as axonal damage in both the central and peripheral nervous system. Diffusion tensor imaging (DTI) has emerged as a powerful noninvasive technique that is sensitive to these white matter disease processes. Increases in radial diffusivity (λ?) and decreases in axial diffusivity (λ∥) correlate with histopathological evidence of demyelination and axonal damage, respectively. Compared to age‐matched, normal littermates, DTI of optic nerve and trigeminal nerve in end‐stage Twitcher mice displayed a statistically significant increase in λ? and decrease in λ∥, consistent with previously characterized demyelination and axonal damage in these regions. In the Twitcher spinal cord, a statistically significant decrease in λ∥ was identified in both the dorsal and ventrolateral white matter, relative to normal controls. These results were consistent with immunofluorescence evidence of axonal damage in these areas as detected by staining for nonphosphorylated neurofilaments (SMI32). Increase in λ? in Twitcher spinal cord white matter relative to normal controls reached statistical significance in the dorsal columns and approached statistical significance in the ventrolateral region. Correlative reduced levels of myelin basic protein were detected by immunofluorescent staining in both these white matter regions in the Twitcher spinal cord. Fractional anisotropy, a nonspecific but sensitive indicator of white matter disease, was significantly reduced in the optic nerve, trigeminal nerve, and throughout the spinal cord white matter of Twitcher mice, relative to normal controls. This first reported application of spinal cord DTI in the setting of GLD holds potential as a noninvasive, quantitative assay of therapeutic efficacy in future treatment studies. Copyright © 2009 John Wiley & Sons, Ltd.