局限性硬皮病:MR表现与临床特征

目的描述局限性硬皮病骨骼肌肉系统的MR表现,并探讨MR表现与临床亚型的关系,临床怀疑存在骨骼肌肉系统改变的病人的MR表现。材料与方法本研究获得大学伦理审查委员会的批准。2005年11月—2010年6月局     

肘关节尺神经病:MR神经成像——神经T_2信号增高与直径测量

目的评价尺神经的T2信号及直径大小在肘关节尺神经疾病(UNE)MR神经成像中的诊断效能。材料与方法本研究为前瞻性研究,经机构审查委员会批准,所有参与者     

有与没有MRI过高扩散信号的胎龄相近早产儿:神经发育结果的对照性研究

正摘要目的联系其他脑白质病变,对照MR影像上有过高扩散信号(DEHSI)与没有DEHSI早产儿神经发育的结果。材料与方法此项回顾性研究由机构审查委员会批准,免除获得知情同意通知的要求。126例高危早产儿于相似胎龄时接受了脑MRI复查,并依据是否有DEHSI分为两组。于生后18个月与24个月时     

肘关节尺神经病:MR神经成像——神经T2信号增高与直径测量

目的评价尺神经的T2信号及直径大小在肘关节尺神经疾病(UNE)MR神经成像中的诊断效能。材料与方法本研究为前瞻性研究,经机构审查委员会批准,所有参与者     

CO中毒后迟发性帕金森症:应用反转恢复MR成像评价黑质

摘要目的应用灰质(GM)抑制反转恢复序列(IR)MRI定量研究CO中毒后迟发性帕金森症病人的黑质信号改变。材料与方法本前瞻性研究经当地伦理审查委员会批准且所有受试者均签署知情同意书。     

扩散加权成像与常规MR成像在新生儿缺氧缺血中的应用：2年的随访研究

目的 通过对缺血缺氧的新生儿2年后临床预后的评估,明确扩散加权成像（DWI）对于常规MR成像的信息补充价值。材料和方法 46例缺血缺氧新生儿作为本项前瞻性研究对象．年龄在出生后1～45d不等。这项研究经过了当地伦理委员会的认可,告知患儿家属并获得同意。在大脑14个不同的区域测定表观扩散系数（ADC）。     

多发性硬化脑铁含量MRI纵向观察:该病的一种影像标志物

正目的研究多发性硬化(MS)病人为期2年的脑铁含量MRI标志物与病变程度之间的相关性。材料与方法本研究为前瞻性研究,经当地医疗机构伦理委员会批准,所有     

非酒精性脂肪肝的体素内不相干运动扩散加权成像:一项3.0TMRI研究

摘要目的对伴发脂肪肝和不伴发脂肪肝的2型糖尿病病人MR扩散加权[DW,基于体素内不相干运动(IVIM)理论]成像的纯分子扩散(D)、灌注相关扩散(D)及灌注分数(f)进行比较。材料与方法本前瞻性研究获得伦理委员会的批准,所有病人均签署知情同意书。     

MR兼容性气动驱动设备作为经直肠前列腺活检导航的可行性研究

目的评估使用一种与MR兼容的遥控气动驱动机械装置在实时动态3TMR影像引导下进行经直肠前列腺活检的可行性。材料与方法本前瞻性研究经伦理审查委员会     

新生儿侧脑室新参考值

目的通过大样本队列分析,建立24~42周胎龄新生儿侧脑室横径新参考值,以及胎龄小于30周早产儿的纵径参考值。材料与方法本研究为前瞻性研究,已通过机构伦理审查委员会审查,父母签署知情同意书。共625例新生儿     

Deep white matter infarction: correlation of MR imaging and histopathologic findings

Focal and confluent areas of periventricular hyperintensity have been reported on magnetic resonance (MR) images in 30% of patients over 60 years of age. In order to better understand the pathologic basis of these lesions, the authors studied 14 formalin-fixed brains with MR imaging. Multiple focal areas of hyperintensity were identified in the periventricular white matter in three of the 14 brains studied (21%). Subsequent gross and microscopic pathologic examination of both hyperintense and normal-intensity areas was performed on 87 tissue sections. The larger lesions were characterized centrally by necrosis, axonal loss, and demyelination and therefore represent true infarcts. Reactive astrocytes oriented along the degenerated axons were identified at distances of up to several centimeters from the central infarct. This is called isomorphic gliosis and is associated with increased intensity on T2-weighted images that increases the apparent size of the central lesion.     

Comparing brain white matter on sequential cranial ultrasound and MRI in very preterm infants

INTRODUCTION: Periventricular white matter (WM) echodensities, frequently seen in preterm infants, can be associated with suboptimal neurodevelopment. Major WM injury is well detected on cranial ultrasound (cUS). cUS seems less sensitive for diffuse or more subtle WM injury. Our aim was to assess the value of cUS and magnetic resonance imaging (MRI) for evaluating WM changes and the predictive value of cUS and/or MRI findings for neurodevelopmental outcome in very preterm infants with normal to severely abnormal WM on sequential high-quality cUS. MATERIALS AND METHODS: Very preterm infants (<32 weeks) who had sequential cUS and one MRI within the first three postnatal months were included. Periventricular WM on cUS and MRI was compared and correlated with neurodevelopmental outcome at 2 years corrected age. RESULTS: Forty preterm infants were studied; outcome data were available in 32. WM changes on sequential cUS were predictive of WM changes on MRI. Severely abnormal WM on cUS/MRI was predictive of adverse outcome, and normal-mildly abnormal WM of favorable outcome. Moderately abnormal WM on cUS/MRI was associated with variable outcome. Additional MRI slightly increased the predictive value of cUS in severe WM changes. CONCLUSION: Sequential cUS in preterm infants is reliable for detecting WM changes and predicting favorable and severely abnormal outcome. Conventional and diffusion-weighted MRI sequences before term equivalent age in very preterm infants, suggested on cUS to have mild to moderately abnormal WM, do not seem to be warranted.     

磁共振成像T2客观定量测量等同足月早产儿大脑白质信号强度的研究

目的对比大脑白质（WM）定量的B值测定和常规T2WMRI的定性评价,评价早产儿大脑WMT2和局域特异表观扩散系数（ADC）的关系,检查早产儿等同足月时WMT2局部变化。材料与方法研究经本地医学伦理委员会批准并获取每例婴儿的知情同意通知。小于32孕周的62名早产儿和7名作为对照的正常新生儿在1．5TMR设备上进行了扫描,获取T2加权的快速自旋回波序列MR影像、T2数据及扩散加权MR影像。     

MR features of developing periventricular white matter in preterm infants: evidence of glial cell migration.

PURPOSEMR imaging of the brain is increasingly used in the investigation of the newborn, but little information is available on the normal appearance of the developing brain. We scanned a series of newborn infants in an attempt to define the normal appearance of developing periventricular white matter and to assess how pathologic conditions may modify this appearance.METHODSSixty-eight newborn infants, median postmenstrual age (PMA) 34 weeks (range, 24 to 42 weeks), were subdivided into two groups: group A (n = 33), which included those with normal clinical and sonographic examinations, and group B (n = 35), which contained those with evidence of neuroabnormality detected prior to the MR study, either clinically or by cerebral sonography. Images were acquired in two planes on a 1.5-T imager using turbo spin-echo pulse sequences.RESULTSSymmetric periventricular bands of reduced signal intensity were noted in the frontal periventricular white matter on T2-weighted images in 98% of group A infants and in 97% of group B infants. The number of bands was inversely related to PMA. The reduction in number of bands with increasing PMA was delayed in group B infants.CONCLUSIONThe uniform appearance of periventricular bands in a population of healthy infants and their relationship to the infants'' maturity is consistent with the results of previous histologic studies. These studies demonstrate the presence of migrating glial cells within the periventricular white matter of infants beyond 20 weeks'' gestation, when neuronal migration to the cortex is complete. We postulate that the bands seen on T2-weighted images represent groups of migrating glial cells, providing a further marker of cerebral maturation.     

Microvascular abnormality in relapsing-remitting multiple sclerosis: perfusion MR imaging findings in normal-appearing white matter

PURPOSE: To prospectively determine hemodynamic changes in the normal-appearing white matter (NAWM) of patients with relapsing-remitting multiple sclerosis (RR-MS) by using dynamic susceptibility contrast material-enhanced perfusion magnetic resonance (MR) imaging. MATERIALS AND METHODS: Conventional MR imaging (which included acquisition of pre- and postcontrast transverse T1-weighted, fluid-attenuated inversion recovery, and T2-weighted images) and dynamic susceptibility contrast-enhanced T2*-weighted MR imaging were performed in 17 patients with RR-MS (five men and 12 women; median age, 38.4 years; age range, 27.6-56.9 years) and 17 control patients (seven men and 10 women; median age, 42.0 years; age range, 18.7-62.5 years). Absolute cerebral blood volume (CBV), absolute cerebral blood flow (CBF), and mean transit time (MTT) (referenced to an arterial input function by using an automated method) were determined in periventricular, intermediate, and subcortical regions of NAWM at the level of the lateral ventricles. Least-squares regression analysis (controlled for age and sex) was used to compare perfusion measures in each region between patients with RR-MS and control patients. Repeated-measures analysis of variance and the Tukey honestly significant difference test were used to perform pairwise comparison of brain regions in terms of each perfusion measure. RESULTS: Each region of NAWM in patients with RR-MS had significantly decreased CBF (P <.005) and prolonged MTT (P <.001) compared with the corresponding region in control patients. No significant differences in CBV were found between patients with RR-MS and control patients in any of the corresponding areas of NAWM examined. In control patients, periventricular NAWM regions had significantly higher CBF (P =.03) and CBV (P =.04) than did intermediate NAWM regions. No significant regional differences in CBF, CBV, or MTT were found in patients with RR-MS. CONCLUSION: The NAWM of patients with RR-MS shows decreased perfusion compared with that of controls.     

MR imaging assessment of myelination in the very preterm brain

BACKGROUND AND PURPOSE: MR imaging was performed in very preterm infants by using an MR imager in the neonatal intensive care unit. The aims of this study were to assess the development of myelination in the preterm brain based on MR imaging findings and to compare the ability of T1-weighted conventional spin-echo, inversion recovery fast spin-echo, and T2-weighted fast spin-echo MR imaging to show myelination in these infants. METHODS: MR imaging was performed for 26 preterm infants with a median gestational age of 28 weeks who had normal neurodevelopmental outcomes at 2 years corrected age. RESULTS: Myelin was evident in the gracile and cuneate nuclei and fasciculi, vestibular nuclei, cerebellar vermis, inferior and superior cerebellar peduncles, dentate nucleus, medial longitudinal fasciculus, medial geniculate bodies, subthalamic nuclei, inferior olivary nuclei, ventrolateral nuclei of the thalamus, decussation of the superior cerebellar peduncles, medial lemnisci, lateral lemnisci, and inferior colliculi at < or = 28 weeks gestational age. From this gestational age, myelination was not visualized at any new site until 36 weeks gestational age, when myelin was visualized in the corona radiata, posterior limb of the internal capsule, corticospinal tracts of the precentral and postcentral gyri, and lateral geniculate bodies. T2-weighted fast spin-echo MR imaging showed myelin in gray matter nuclei at an earlier gestational age than did T1-weighted conventional spin-echo or inversion recovery fast spin-echo MR imaging. T1-weighted conventional spin-echo MR imaging showed myelin earlier in some white matter tracts in the preterm brain. CONCLUSION: Myelination was evident in numerous gray and white matter structures in the very preterm brain. A knowledge of myelination milestones will allow delays to be detected at an early stage.