遗传性痉挛性截瘫伴薄胼胝体的影像学表现

目的：分析遗传性痉挛性截瘫伴薄胼胝体（HSP-TCC）的影像学特点,以提高对此病的认识。方法：结合文献复习并报告一家族3例HSP-TCC患者的影像学表现。结果：本组3例HSP-TCC患者均显示胼胝体菲薄、颈胸髓明显变细,内见长T2信号、弥漫性非特异性脑白质病变和轻度脑萎缩。结论：HSP-TCC可广泛影响中枢神经系统,MRI特异性表现包括薄胼胝体,侧脑室周围白质长T2信号,脊髓萎缩及信号异常及后期出现轻度到中度脑萎缩。     

Abnormalities of the corpus callosum in nonpsychotic children with chromosome 22q11 deletion syndrome

Chromosome 22q11 deletion syndrome (22q11DS) is associated with elevated rates of schizophrenia and other psychoses in adulthood. Childhood morphologic brain abnormalities are frequently reported, but the significance of these and their relationship to the development of schizophrenia are unclear. We sought to delineate midline neuroanatomical abnormalities in nonpsychotic children with 22q11DS and their age- and sex-matched controls and compare these to those reported in individuals with schizophrenia. On qualitative analysis, we found a high incidence of midline developmental abnormalities (cavum septum pellucidum, or CSP). On quantitative analysis, the total corpus callosum (CC) area was significantly increased in the patient group and among the subregions, the patients had a significantly larger isthmus. These findings of an increased area of the corpus callosum, specifically the isthmus, have not been reported before in individuals with 22q11DS. We also found a relative lack of the age-related increase in the size of the corpus callosum in the children with 22q11DS. There were no differences in cerebellar vermis measurements between the patient and control groups. Our findings are indicative of frequent midline brain anomalies, including dysgenesis of the corpus callosum, in nonpsychotic children with 22q11DS. Although the increased size of the corpus callosum in our 22q11DS patients is in direct contrast to the decrease seen in schizophrenia, the high frequency of structural midline abnormalities in these nonpsychotic children with 22q11DS is similar to that seen in schizophrenia. Further longitudinal studies on these children will help determine which of these structural abnormalities is/are pertinent to the development of psychosis.     

Age-related degeneration of corpus callosum measured with diffusion tensor imaging

The corpus callosum is the major commissure connecting the cerebral hemispheres, and there is evidence of its change with aging. The sub-regions of the corpus callosum (genu, rostral body, anterior midbody, posterior midbody, isthmus, splenium) respectively comprise fibers connecting heteromodal- and unimodal-associated cortical regions, and it is known that abnormalities of the corpus callosum are correlated with abnormalities in cognition and behavior. Yet, little is known about changes in the tissue characteristics of its sub-regions. We assessed age-related changes in fractional anisotropy and mean diffusivity in the sub-regions of the corpus callosum using diffusion tensor imaging. We studied 42 healthy right-handed individuals aged 21-73 years. There were no significant interactions of sex x region. Age has significant negative correlation with fractional anisotropy in the genu (P < 0.001), rostral body (P < 0.001), and isthmus (P = 0.005). Fractional anisotropy of the anterior midbody was correlated negatively with age at a trend level (P = 0.022). Age was significantly positively correlated with mean diffusivity in the genu (P = 0.001), rostral body (P = 0.002), anterior midbody (P = 0.001), and isthmus (P = 0.001). Age-related changes were detected in the sub-regions where their projection areas are thought to be vulnerable to normal aging. This suggested that fractional anisotropy and mean diffusivity values of the corpus callosum sub-regions could serve as markers of disturbance across the respective projection areas.     

In vivo quantification of global connectivity in the human corpus callosum

Histological studies on nonhuman primates have shown a rich topography of homotopic (i.e., going to the same regions) or heterotopic (i.e., going to different regions) callosal projections. Unfortunately, a complete within-subject mapping of commissural projections in humans has been limited due to the inability of typical imaging methods to detect lateral projections in posterior cortical regions. Here, we set out to map callosal projection connectivity, at the single subject level (N = 6), by combining high angular resolution diffusion weighted imaging and a novel multi-stage, region-of-interest (ROI) based fiber tracking approach. With these methods we were able to obtain a consistent increase in coverage of lateral projections to posterior cortical regions. Using 70 automatically segmented ROIs in each hemisphere and permutation statistics, we characterized significant interhemispheric connectivity patterns within each subject and observed: (1) consistent projections to frontal, parietal and occipital, but not temporal, areas, (2) a greater relative proportion of homotopic than heterotopic connections, and (3) commissural projections to the basal ganglia and thalamus that are consistent with human and nonhuman primate neuroanatomical literature. These results illustrate the first full connectivity analysis of the human corpus callosum, revealing several patterns consistent with histological findings in the nonhuman primate.     

多发性硬化患者胼胝体的弥散张量纤维束成像定量研究

目的利用弥散张量纤维束成像(DTT)定量研究多发性硬化(MS)患者胼胝体分数各向异性(FA)值与正常志愿者之间的差异及与扩展病残状态评分(EDSS)的相关性,以明确该指标在多发性硬化研究中的价值.方法对36例正常志愿者和64例复发好转型(RR)MS患者进行弥散张量成像检查,重建出胼胝体并计算出该纤维束的FA值,比较MS组与对照组之间是否存在差异,研究该指标与EDSS的相关性.结果正常志愿者胼胝体FA值无性别差异(P＞0.05),平均FA值为0.506±0.020.MS患者胼胝体平均FA值(0.465±0.033)明显低于(P＜0.01)对照组(0.506±0.020).脑型MS胼胝体平均FA值(0.456±0.036)明显低于脊髓型(0.475±0.025)(P＜0.05).MS患者胼胝体FA值与EDSS评分无显著相关性(r=-0.104,P＞0.05).结论MS患者胼胝体的FA值存在明显异常,但该指标不能反映患者的身体残疾状态.     

多发性硬化患者磁共振T1加权像胼胝体纹理特性分析

目的 研究MS患者常规磁共振图像(cMRI)上表现正常的胼胝体部位的纹理特征及其方向特性,为显示MS患者脑组织的隐匿性损伤提供新的方法.方法 选取37例复发-缓解型MS患者和年龄、性别匹配的37例健康对照者图像,在cMRI上表现正常胼胝体的矢状位T1加权图像提取膝部、压部、体部感兴趣区,分别组成三个部位的MS组和对照组样本集,映射成灰度共生矩阵,然后提取能量、逆差矩、熵等纹理参量,比较各部位两组间的纹理特征差异.结果胼胝体膝部和压部在0°、45°、90°和135°四个方向,MS组能量和逆差矩值明显高于对照组,熵值明显低于对照组(P＜0.05);体部在0°、45°和135°方向逆差矩值显著高于对照组(P＜0.05).结论 MS患者MRI的T1加权图像上表现正常胼胝体的纹理特征与健康对照组具有显著性差异,特别是膝部和压部更为显著.纹理特征分析为显示MS患者cMRI上表现正常脑组织的隐匿性病变提供了新方法.     

多发性硬化早期胼胝体的DTI改变

目的：探讨多发性硬化（MS）早期常规MR扫描表现正常的胼胝体的磁共振弥散张量成像（DTI）的改变。方法：20例病程相对较短（平均2.3年）的MS患者和20个年龄性别相匹配的健康志愿者为对照进行MR扫描,获取高分辨常规MRI（T1WI、T2WI、FLAIR）图像及DTI图像,获得表现正常胼胝体（NACC）和额、枕区的表现正常白质（NAWM）的部分各向异性指数（FA）值和平均扩散系数（MD）值。结果：早期MS患者的NACC与正常对照比较其FA值显著下降（P＜0.001）、MD值显著增加（P＜0.001）,但早期MS患者额、枕区的NAWM和正常对照比较其FA值（P=0.216）、MD值（P=0.673）差异均无统计学意义。NACC区的平均MD值和反映脑实质中央性萎缩的Evans指数间存在相关性（r＝0.648,P=0.043）。结论：定量磁共振弥散张量值（FA值和MD值）的变化表明MS疾病早期损害优先出现在胼胝体,胼胝体的结构特点可能是其在MS早期易受损害的重要原因。定量DTI可用于监控和评估早期MS患者NACC的改变和预后。     

A critical re-examination of sexual dimorphism in the corpus callosum microstructure

Recent diffusion-tensor imaging (DTI) studies suggest sexual dimorphism in the micro-structural architecture of the corpus callosum. However, the corpus callosum is also found to be larger in males than in females, a fact that might introduce a systematic bias to the analysis of DTI parameters. Diffusion parameters obtained in the larger male corpus callosum could be less affected by partial-volume averaging with surrounding non-callosal tissue than respective parameters obtained in the smaller female corpus callosum, i.e. the sex of the subject and partial-volume effects would be confounded. The objective of the present DTI study was to re-examine microstructural sex differences in the corpus callosum, while controlling for corpus callosum size differences between sexes. We compared 41 female and 34 male participants using regional tract-based spatial statistics (TBSS) analysis. Clusters of significantly higher fractional anisotropy (FA) and lower diffusion strength in males compared to females were detected in the genu and truncus of the corpus callosum. However, only the sex difference located in the anterior genu subregions could be unequivocally interpreted. This was the only cluster where the diffusion parameters did not correlate with regional callosal size. The present results indicate a stronger inter-hemispheric connectivity between the frontal lobes in males than females, which might be related to sex differences in hemispheric asymmetry and brain size.     

Cardiorespiratory fitness is positively correlated with cerebral white matter integrity in healthy seniors

High cardiorespiratory fitness (CRF) is an important protective factor reducing the risk of cardiac-related disability and mortality. Recent research suggests that high CRF also has protective effects on the brain's macrostructure and functional response. However, little is known about the potential relationship between CRF and the brain's white matter (WM) microstructure. This study explored the relationship between a comprehensive measure of CRF (VO₂ peak, total time on treadmill, and 1-minute heart rate recovery) and multiple diffusion tensor imaging measures of WM integrity. Participants were 26 healthy community dwelling seniors between the ages of 60 and 69 (mean = 64.79 years, SD = 2.8). Results indicated a positive correlation between comprehensive CRF and fractional anisotropy (FA) in a large portion of the corpus callosum. Both VO₂ peak and total time on treadmill contributed significantly to explaining the variance in mean FA in this region. The CRF-FA relationship observed in the corpus callosum was primarily characterized by a negative correlation between CRF and radial diffusivity in the absence of CRF correlations with either axial diffusivity or mean diffusivity. Tractography results demonstrated that portions of the corpus callosum associated with CRF primarily involved those interconnecting frontal regions associated with high-level motor planning. These results suggest that high CRF may attenuate age-related myelin declines in portions of the corpus callosum that interconnect homologous premotor cortex regions involved in motor planning.     

磁共振与超声诊断胎儿胼胝体发育不全的对比

目的 探讨MR和超声(US)对胎儿胼胝体发育不全(ACC)的产前诊断价值。方法 US提示胎儿颅内异常孕妇32例,均在US检查后1天内接受胎儿MR检查,对出生或引产胎儿行影像学检查及尸检,并与产前US、MR结果对照,评价US和MR检查的诊断准确率。结果 32胎US检出颅脑发育异常胎儿中,MR诊断为ACC 32胎(包括完全型ACC 26胎,部分型ACC 6胎)。MR与US比较,诊断胎儿ACC一致者 17胎;US可疑ACC 6胎、未发现ACC 9胎,这15胎MR均肯定ACC。单纯ACC 18胎, ACC伴发其他畸形14胎;对于其他伴发畸形, MR发现伴发畸形多于 US为8胎,2胎伴发畸形MR诊断与引产后病理不符。 结论 MR有助于明确诊断胎儿 ACC 并判断其分型及伴发畸形,可作为US有利的补充及验证手段。     

孤独症患儿胼胝体磁共振形态及扩散张量成像

目的 通过胼胝体磁共振形态及扩散张量成像(DTI)观察孤独症患儿胼胝体形态及细微结构异常,探讨其可能的发生机制.方法 对13例男性孤独症患儿(孤独症组)及15名正常男童(正常对照组)进行胼胝体结构磁共振形态及DTI观察,测量胼胝体正中矢状面前部、体部、后部及总面积,大脑总体积及各相异性分数(FA),并对两组进行对比分析.结果 孤独症组胼胝体前部面积及总面积较正常对照组减小(P<0.05),体部和后部面积与对照组差异无统计学意义(P>0.05);大脑总体积较对照组增大(P<0.05).孤独症组患者胼胝体前部和体部的FA值明显低于正常对照组(P<0.05),后部的FA值两组间差异无统计学意义(P>0.05).结论 孤独症患儿胼胝体前部面积较正常发育儿童明显减小,胼胝体前部及体部FA值明显降低,提示胼胝体局部白质纤维束可能存在微结构的改变.     

运用白质地图分析皮质下缺血性血管病患者胼胝体损害与认知功能的关系

目的 采用基于白质地图的DTI分析方法(ABA)探讨皮质下缺血性血管病(SIVD)患者胼胝体损害与认知功能的关系。方法 对18例血管性认知障碍(VCI组)和22例无认知障碍(NCI组)的SIVD患者进行神经心理学和MR检查,采用白质地图DTI比较两组患者胼胝体各分区的FA、平均扩散率(MD)的差异,并分析上述DTI参数与蒙特利尔认知评估量表(MoCA)得分的相关性。结果 与NCI组比较,VCI组在胼胝体膝部、体部、压部、右毯部和左毯部的FA值明显减低,MD明显增高(P均<0.05)。SIVD患者胼胝体膝部、体部、压部、右毯部和左毯部的FA值与MoCA得分呈正相关,胼胝体膝部、体部、压部、右毯部的MD值与MoCA的得分呈负相关。结论 认知障碍的SIVD患者存在胼胝体损害,且损害与认知功能改变相关;采用ABA可以评价疾病的严重程度。     

早产儿胼胝体生长率与神经运动发育关系的超声研究

目的研究早产儿胼胝体生长率与神经运动发育之间的关系。方法胎龄小于34周早产儿50例,于生后0～6周每周颅脑超声测量胼胝体的长度。校正胎龄3个月时,行52项神经运动检查分为异常组14例和正常组36例,分析胼胝体生长率与神经运动检查结果之间的关系。结果早产儿生后2～6周胼胝体增长率低于足月儿（P〈0．01）,早产儿异常组2～6周胼胝体生长率低于正常组（P〈0．01）。结论早产儿校正胎龄3个月时,神经运动发育迟滞可能与2～6周龄时胼胝体生长度低下有关。     

胎儿胼胝体发育不良的超声和磁共振对比观察

目的 探讨超声与MRI在胎儿胼胝体发育不良(ACC)产前诊断中的应用价值。方法 超声怀疑胎儿ACC孕妇16名,均在超声检查后3天内接受胎儿MR检查。将超声、MRI结果与出生后或引产后结果对照。结果 16名孕妇共检出胎儿16胎,MRI证实14胎为胎儿ACC(出生后随访证实5胎,引产后证实9胎),1胎为单纯双侧脑室扩张伴灰质易位,1胎为脑白质、脑干发育不良。MRI与超声比较,诊断胎儿ACC一致者7胎;超声可疑、MRI肯定者7胎;对于其伴发中枢神经系统畸形,两者一致者7胎,MRI多于超声者4胎。结论 超声检查是产前筛查胎儿ACC的普遍方法;MRI对胎儿ACC的显示明显优于超声,有助于明确诊断胎儿ACC并判断其分型及合并畸形。     

Interhemispheric hypoconnectivity in schizophrenia: fiber integrity and volume differences of the corpus callosum in patients and unaffected relatives

Changes in hemispheric asymmetry and inter-hemispheric connectivity have been reported in schizophrenia. However, the genetic contribution to these alterations is still unclear. In the current study, we applied an automatic segmentation method to structural MRI and diffusion tensor imaging (DTI) data and examined volume and fiber integrity of the corpus callosum (CC), the main interhemispheric fiber tract, in 16 chronic schizophrenia (SZ) patients, matched first degree relatives and controls. SZ patients and relatives had smaller CC volumes than controls, particularly in the posterior genu, isthmus and splenium. Fractional anisotropy (FA), an indicator of fiber integrity, was reduced in patients and relatives in the whole CC, the inferior genu, the superior genu and the isthmus. Correspondingly, the mean diffusivity (MD) values of the whole CC and the isthmus were higher in patients and their unaffected relatives, indicating decreased compactness and increased intercellular space. Relatives had intermediate values in the volumetric and fiber integrity measurements between patients and controls. Lower CC volume and fiber integrity in SZ patients were associated with more severe auditory hallucinations. These results support the connectivity hypothesis of SZ (Friston, 1998) and particularly highlight the altered interhemispheric connectivity, which appears to be a genetic feature of SZ risk.     

急性一氧化碳中毒后大鼠胼胝体损伤的实验研究

目的 探讨急性一氧化碳(CO)中毒后迟发性脑病(DE)大鼠胼胝体损伤情况.方法 健康雄性Wistar大鼠,分次腹腔注射CO制备迟发性脑病模型.于中毒后第1、2、3、5、7、14、20天和对照组各时间段取胼胝体,常规制备石蜡病理切片,行HE染色观察细胞形态,变色酸染色观察髓鞘变化.于中毒后第7天和对照组相应时间段每组各8只大鼠取胼胝体,透视电镜观察髓鞘变化.于中毒后第7天和对照组相应时间段每组各8只大鼠取胼胝体,蛋白印迹试验检测髓鞘碱性蛋白(MBP)的相对含量.八臂迷宫实验训练并检测大鼠认知功能.结果 光镜下观察见HE染色中毒组出现白质疏松、泡沫细胞形成,胶质细胞肿胀、反应性增生等变化,以中毒后第7天为著.变色酸染色可见中毒组因纤维脱髓鞘而出现淡染区、泡沫细胞形成,以中毒后第7天为著.透视电镜下见胼胝体髓鞘板层结构紊乱,出现松解、断裂.蛋白印迹试验显示,中毒后胼胝体MBP下降.结论 CO中毒后随着时间推移,大鼠胼胝体出现不同程度的神经脱髓鞘改变.     

中晚孕期胎儿胼胝体观察新方法：二维颅脑横切面法

目的确定二维超声颅脑横切面上胼胝体观测切面及建立20周至足月正常胎儿横切面上胼胝体各径线参考值。 方法选取2018年6月至2018年12月在南方医科大学附属深圳妇幼保健院行产前超声检查诊断无结构异常且因"计划外生育"或者母体宫颈机能不全在我院引产，其父母同意尸体解剖的10例20~30周单胎胎儿作为研究对象。采用三维自由解剖成像法和冰冻标本解剖法获取胼胝体的系列横切面/横断面。观察上述两种方法获取的系列横切/断面，总结各切面及对应断面的特征，得出横切面上胼胝体结构观察的稳定切面。选取同时期在南方医科大学附属深圳妇幼保健院常规产前超声检查无结构异常的670例孕20周至足月的单胎胎儿，在第一部分选定的胼胝体横切面进行胼胝体膝部前角、后角，压部前角、后角，胼胝体最大前后径，膝部左右径、前后径，压部左右径、前后径，体部前后径、左右径的测量。随机抽取40例胎儿行上述参数两测量者间的重复性检验；建立各孕周颅脑横切面上胼胝体各参数的正常参考值范围，绘制所测数据与孕周的散点图并行相关性分析，建立线性回归方程。 结果三维自由解剖成像法和冰冻标本解剖法所获胼胝体3个横切面恒定显示相同的解剖结构。两观察者之间的重复性检验未见明显差异。各散点图显示正常胎儿胼胝体各参数测值与孕周呈正相关（r=0.232、0.343、0.284、0.182、0.913、0.895、0.748、0.787、0.736、0.684、0.734，P均<0.01）。对各参数与孕周进行回归分析，回归方程分别为：Y=0.514X＋52.214，Y=0.785X＋42.897，Y=0.600X＋47.327，Y=0.436X＋53.056，Y=0.117X＋0.019，Y=0.070X-0.169，Y＝0.013X＋0.054，Y=0.065X＋0.180，Y=0.014X＋0.064，Y=0.047X＋0.547，Y=0.027X-0.116。 结论基于三维自由解剖成像和冰冻标本解剖确定的系列切面相对固定，可作为胼胝体结构评估的切面。不同孕周胎儿胼胝体各径线正常参考值可作为产前评估胼胝体发育异常的参考依据。     

二维横切面新方法对胎儿胼胝体结构异常的诊断价值

目的探讨二维横切面法所得正常参考值范围对胼胝体结构异常的诊断价值。 方法选择2018年6月至2020年7月在南方医科大学附属深圳妇幼保健院行产前超声检查并使用二维颅脑横切面法筛查20周至足月的670例正常胎儿（正常组）,疑诊胼胝体结构异常并经产前/后磁共振检查、产后超声或尸体解剖证实的胎儿77例（异常组）。胼胝体结构异常组分为4组：完全缺如组、部分缺如组、变薄组和变短组。对所有胎儿进行横切面上胼胝体最大前后径、膝部左右径和前后径、体部左右径和前后径、压部左右径和前后径、膝部前角和后角、压部前角和后角的测量。采用非参数检验比较正常组与异常组参数的差异。绘制异常组与正常组所有测量参数的复合散点图。 结果670例正常组和77例异常组孕妇年龄和孕周比较［30（28,33）岁 vs 30（26,34）岁;28（24,32）周 vs 25（23,28）周］,差异均无统计学意义（P均＞0.05）。正常组中,横切面和正中矢状切面的显示率分别为100%、13.9%。而在异常组中,横切面和正中矢状切面的显示率分别为100%、62.3%。胼胝体异常组膝部前角及后角、压部前角及后角、膝部前后径、胼胝体最大前后径、膝部左右径、压部左右径、压部前后径、体部左右径和体部前后径测值均低于正常组［48.00°（0°,80.68°）vs（66.76°±10.79°）;44.00°（0°,79.30°）vs 65.10°（49.30°,83.00°）;41.90°（0°,69.37°）vs（64.31°±10.27°）;38.50°（0°,72.10°）vs（65.38°±11.65°）;0.21（0,0.40）cm vs（0.44±0.09）cm;1.10（0,2.78）cm vs 3.33（2.11,4.20）cm;1.18（0,2.23）cm vs 1.81（1.22,2.46）cm;1.21（0,2.20）cm vs（2.02±0.40）cm;0.18（0,0.35）cm vs 0.45（0.32,0.63）cm;0.42（0,1.01）cm vs 0.62（0.40,0.98）cm;0.75（0,1.87）cm vs（1.86±0.33）cm］,差异均具有统计学意义（Z=-8.959、-8.650、-9.839、-9.993、-12.812、-13.668、-7.343、-10.521、-12.145、-5.260、-14.034,P均＜0.001）。各异常组与正常组的复合散点图结果显示胼胝体最大前后径显著低于正常胎儿测值第5百分位线;胼胝体厚度变薄的发育不良组膝部和压部前后径明显低于正常胎儿测值第5百分位线,其他参数在复合散点图上差异不明显。 结论产前二维超声颅脑横切面法能较好地评估中晚孕期胎儿胼胝体异常相关结构的大小,对胼胝体结构异常胎儿的胼胝体大小评估具有参考价值,尤其是胼胝体最大前后径适用于绝大部分胼胝体结构异常评估,胼胝体膝部前后径及压部前后径对于胼胝体变薄型发育不良有参考价值,其他参数对胼胝体结构异常的诊断参考意义不大。     

Prenatal genetic testing in 19 fetuses with corpus callosum abnormality

BackgroundCorpus callosum abnormality (CCA) can lead to epilepsy, moderate severe neurologic or mental retardation. The prognosis of CCA is closely related to genetic etiology. However, copy number variations (CNVs) associated with fetal CCA are still limited and need to be further identified. Only a few scattered cases have been reported to diagnose CCA by whole exome sequencing (WES).MethodsKaryotyping analysis, copy number variation sequencing (CNV‐seq), chromosomal microarray analysis (CMA) and WES were parallelly performed for prenatal diagnosis of 19 CCA cases.ResultsThe total detection rate of karyotyping analysis, CMA (or CNV‐seq) and WES were 15.79% (3/19), 21.05% (4/19) and 40.00% (2/5), respectively. Two cases (case 11 and case 15) were diagnosed as aneuploidy (47, XY, + 13 and 47, XX, + 21) by karyotyping analysis and CNV‐seq. Karyotyping analysis revealed an unknown origin fragment (46,XY,add(13)(p11.2)) in case 3, which was further confirmed to originate from p13.3p11.2 of chromosome 17 by CNV‐seq. CMA revealed arr1q43q44 (238923617–246964774) × 1(8.04 Mb) in case 8 with a negative result of chromosome karyotype. WES revealed that 2 of 5 cases with negative results of karyotyping and CNV‐seq or CMA carried pathogenic genes ALDH7A1 and ARID1B.ConclusionParallel genetic tests showed that CNV‐seq and CMA are able to identify additional, clinically significant cytogenetic information of CCA compared to karyotyping; WES significantly improves the detection rate of genetic etiology of CCA. For the patients with a negative results of CNV‐seq or CMA, further WES test is recommended.     

弥散加权成像观察胼胝体发育异常胎儿脑发育

目的 采用弥散加权成像(DWI)观察胼胝体发育异常胎儿脑组织发育。方法 回顾性分析100名接受产前胎儿MR检查的单胎妊娠孕妇资料,根据胎儿胼胝体发育异常与否分为异常组(n=25)和正常组(n=75),测量双侧额叶、顶叶、颞叶、枕叶、小脑半球、半卵圆中心及脑桥表观弥散系数(ADC)并比较其组间差异,分析其随孕周变化规律。结果 100胎左、右侧脑区ADC差异均无统计学意义(P均＞0.05)。异常组与正常组胎儿颞叶ADC差异有统计学意义(P＜0.05),且顶叶ADC均最高(1.85×10^－3 mm²/s、1.87×10^－3mm²/s)而脑桥ADC均最低(1.32×10^－3 mm²/s、1.31×10^－3mm²/s)。异常组胎儿各脑区ADC与孕周均无明显相关性(P均＞0.05)。正常组胎儿额叶、顶叶、颞叶、枕叶及半卵圆中心ADC与孕周存在曲线相关(r=0.50、0.26、0.51、0.25、0.33,P均＜0.05),小脑半球及脑桥ADC与孕周呈线性负相关(r=－0.31、－0.23,P均＜0.05)。结论 胼胝体发育异常胎儿颞叶ADC高于正常胎儿, 且其各脑区ADC均与孕周无明显相关性。