利用3.0T磁共振观察子宫恶性肿瘤组织弥散效应的初步研究

目的： 利用磁共振成像（MRI）的弥散加权成像（DWI）技术,观察子宫恶性肿瘤的弥散受限程度。方法: 采用3.0 T磁共振成像仪,对子宫颈癌病例及正常子宫颈对照组、子宫内膜癌病例及正常子宫内膜对照组进行常规MRI及DWI扫描,测量其表观弥散系数（ADC）,并对子宫颈癌与正常子宫颈、子宫内膜癌与正常子宫内膜的ADC值进行统计学分析。结果: (1)37例子宫颈癌和16例正常子宫颈的ADC值分别为（0.92±0.20）×10-3 mm2/s和（1.26±0.24）×10-3 mm2/s,子宫颈癌和正常子宫颈2组ADC值比较有显著差异（P<0.01）。(2)14例子宫内膜癌和14例正常子宫内膜的ADC值分别为（0.87±0.17）×10-3 mm2/s和 （1.34±0.26）×10-3 mm2/s,子宫内膜癌和正常子宫内膜2组ADC值比较有显著差异（P<0.01）。结论: 子宫颈癌和子宫内膜癌较正常子宫组织弥散受限,3.0T磁共振DWI的ADC值测量能够定量反映子宫恶性肿瘤的弥散受限程度。     

Diffusion‐weighted imaging in multiple system atrophy: A comparison between clinical subtypes

Multiple system atrophy can be classified into two main types, a Parkinsonian (MSA‐P) and a cerebellar (MSA‐C) variant based on clinical presentation. We obtained diffusion‐weighted magnetic resonance imaging (DWI) in 9 MSA‐P and 12 MSA‐C patients and 11 controls, and correlated DWI changes with disease duration and severity. We found that Trace (D) values in the entire and anterior putamen were significantly higher in MSA‐P than in MSA‐C patients and controls, whereas Trace (D) values in the cerebellum and middle cerebellar peduncle (MCP) were significantly higher in MSA‐C than in MSA‐P patients and controls. Increased disease duration was significantly correlated with increased Trace (D) values in pons of MSA‐P patients, and in cerebellum and MCP of MSA‐C patients. Both UMSARS and UPDRS motor scores positively correlated with entire and posterior putaminal Trace (D) values in MSA‐P patients. The diffusivity changes parallel phenotypical and pathologic differences between MSA‐P and MSA‐C patients, suggesting that DWI is a feasible tool for in vivo evaluation of neurodegeneration in MSA. Based on our findings, Trace (D) measurements in the putamen and pons in MSA‐P patients and in the cerebellum and MCP in MSA‐C patients could serve as quantitative markers for microstructural damage in the course of disease. © 2008 Movement Disorder Society     

Modeling premature brain injury and recovery

Premature birth is a growing and significant public health problem because of the large number of infants that survive with neurodevelopmental sequelae from brain injury. Recent advances in neuroimaging have shown that although some neuroanatomical structures are altered, others improve over time. This review outlines recent insights into brain structure and function in these preterm infants at school age and relevant animal models. These animal models have provided scientists with an opportunity to explore in depth the molecular and cellular mechanisms of injury as well as the potential of the brain for recovery. The endogenous potential that the brain has for neurogenesis and gliogenesis, and how environment contributes to recovery, are also outlined. These preclinical models will provide important insights into the genetic and epigenetic mechanisms responsible for variable degrees of injury and recovery, permitting the exploration of targeted therapies to facilitate recovery in the developing preterm brain.     

Involvement of motor pathways in corticobasal syndrome detected by diffusion tensor tractography

Corticobasal syndrome (CBS) is a progressive parkinsonian disease characterized by cortical and subcortical neuronal loss. Although motor disabilities are a core feature of CBS, the involvement of motor pathways in this condition has not been completely clarified. We used magnetic resonance diffusion tensor imaging (DTI) to study corticospinal and transcallosal motor projections in CBS, and applied fiber tractography to analyze the axonal integrity of white matter projections. Ten patients with CBS were compared with 10 age‐matched healthy controls. Fiber tracts were computed using a Monte‐Carlo simulation approach. Tract‐specific mean values of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were determined. CBS patients showed a reduction of corticospinal tract (CST) fibers on the first affected side with significantly increased ADC and reduced FA values. In the corpus callosum (CC), particularly in the posterior trunk, patients also had significantly reduced fiber projections, with a higher ADC and lower FA than controls. This pattern indicates changes of the white matter integrity in both CST and CC. Thus, magnetic resonance DTI can be used to assess motor pathway involvement in CBS patients. © 2008 Movement Disorder Society     

Diagnostic specificity of the insular cortex abnormalities in first-episode psychotic disorders

Volume reductions of the insular cortex have been described in schizophrenia, but it remains unclear whether other psychotic disorders such as affective psychosis also exhibit insular cortex abnormalities. In this study, we used magnetic resonance imaging to investigate the gray matter volume of the anterior (short) and posterior (long) insular cortices in 162 first-episode patients with various psychotic disorders (46 schizophrenia, 57 schizophreniform disorder, 34 affective psychosis, and 25 other psychoses) and 62 age- and gender-matched healthy comparison subjects. Patients with schizophrenia showed bilateral volume reduction of the anterior and posterior insular cortices compared with controls, but the remaining first-episode psychosis subgroups had normal insular volumes. The volumes of these insular subregions were significantly smaller in schizophrenia patients than in patients with schizophreniform disorder or affective psychoses. There was no association between the insular cortex volume and daily dosage or type of antipsychotic medication in any patient group. These findings suggest that the widespread volume reduction of the insular cortex is specific to established schizophrenia, implicating its role in the neurobiology of clinical characteristics associated with schizophrenia.     

Alzheimer病患者扣带回后部损害磁共振扩散张量成像的研究

目的探讨Alzheimer病(AD)患者扣带回后部磁共振扩散张量成像(DTI)的特点及其与认知功能改变的相关性。方法对16例AD患者和12名健康老人(正常对照组)行DTI、T1Flair及T2Flari检查,测量扣带回后部各向异性分数值(FA)、平均弥散度(MD)及其λ1、λ2及λ33个特征值,分析上述诸项数值与简易精神状态检查量表(MMSE)评分之间的相关性。结果与正常对照组相比,AD组患者扣带回后部的FA值显著降低(P<0.05),而MD、λ1、λ2及λ3值明显升高(均P<0.05);FA值与MMSE评分不相关(r=-0.054,P>0.05),而MD值与MMSE评分呈显著负相关(r=-0.664,P<0.01);λ1、λ2及λ3值均与MMSE评分呈负相关(r=-0.643,r=-0.69,r=-0.654,均P<0.01)。结论AD患者表现为扣带回后部各向异性损害,且损害程度与临床认知功能评分呈负相关;这种损害反映了AD病理机制中皮质-皮质及皮质-皮质下联系的丢失;DTI可以用来监测AD疾病的进展及评价药物的临床疗效。     

Establishment of hormone reference intervals for infants born < 30 weeks' gestation

Objective

Preterm infants, especially those born very preterm (< 32 weeks' gestation), suffer a number of morbidities. Immaturity of the endocrine system and its potential impact on morbidity is the subject of numerous studies. Hormone concentrations are sometimes measured in very preterm infants, however there are little normative data available to be able to interpret the results. The aim of this study was to describe age appropriate hormone reference intervals for babies born less than 30 weeks' gestation.

Study design

Samples were collected at 1, 4, 7, 14, 21, 28 and 42 days after birth from babies born 23–29 weeks' gestation. The serum was analyzed for seven hormones by automated chemiluminescent immunoassay (Siemens Immulite 2000). Results from the 107 infants who survived beyond 40 weeks' corrected gestational age were included in the data analysis.

Results

Cortisol, dehydroepiandrosterone sulfate, growth hormone and progesterone levels were highest during the first seven days with levels up to 10,801 nmol/L; 26.6 μmol/L; 343 mU/L; and > 63.6 nmol/L respectively. Free thyroxine levels were as low as < 2.6 pmol/L for the first 28 days with the nadir at 7 days. Estradiol levels ranged from < 73 to 1626 pmol/L over the six weeks. Reference intervals for IGF-1 could not be established as the levels were below the analyzer's sensitivity. There were no differences in reference intervals between male and female infants.

Conclusions

We describe gestation appropriate reference intervals for six hormones measured in babies born < 30 weeks' gestation. Utilization of these reference intervals permits the correct and timely interpretation of results to the clinician.