巨大浆膜下子宫肌瘤的CT与MRI诊断

目的:探讨巨大浆膜下子宫肌瘤(giant subserous hysteromyoma,GSH)的CT与MRI表现,以期提高诊断水平。方法:回顾性分析15例GSH的CT平扫、增强扫描及14例MRI平扫1、0例增强扫描表现并与手术病理结果对照。结果:5例CT表现呈非均匀实性的GSH在增强后内部呈多个大小不等的结节状改变,其间可见分隔结构,4例呈非均匀实性的GSH增强后呈"漩涡状"混杂密度,3例GSH瘤体边缘见低密度带。MRI T1WI所有肌瘤表现为等、低信号,T2WI表现为低或混杂信号,5例瘤体内部为结节状改变,其间可见高信号分隔结构,7例瘤体边缘见低信号带。结论:GSH的CT与MRI表现有一定的特征性,具有较高的诊断价值。     

Biliary cystadenoma with mesenchymal stroma of the liver: Correlation between unusual MR appearance and pathologic findings

We reported a case of the biliary cystadenoma of the liver. The cystic mass had labulation and septation and showed marked hyperintensity on T1-weighted images and hypointensity on T2-weighted images; MR findings were very unusual for cystadenoma. The content of the cystic mass was jelly-like, thick mucinous fluid without intracystic hemorrhage. We concluded that these unusual signal intensities of the cyst were due to hyperproteinous mucinous fluid.     

MR imaging of dural arteriovenous malformations with ocular signs

Summary Four patients with dural arteriovenous malformation (AVMs) draining into the cavernous sinus, who presented ophthalmic manifestations, were studied by magnetic resonance (MR) imaging. In all patients signal decrease in the involved cavernous sinus was demonstrated in coronal spinecho (SE) imaging. It is attributable to rapid venous flow in the sinus, and this high velocity signal loss is a fairly pathognomonic finding in this condition. We stress the validity of MR imaging in the primary diagnosis of dural AVMs with ophthalmic symptoms.     

磁刺激用平面线圈结构的优化研究

文中建立了采用任意形状平面线圈磁刺激仪的RLC模型，给出了模型参数的计算方法。为了优化线圈，将磁刺激仪线圈的性能指标分为反映线圈输出性能的峰值磁能和反映线圈结构的几何变量。在磁刺激激活函数达到阈值条件下，调整平面螺旋线圈的结构并计算出依赖于线圈结构参数的输出性能值，从而，寻找最优的线圈几何参数。优化结果表明：线圈外半径是关键因素，给定阈值条件，选择合适的线圈外半径，可以大大降低线圈峰值磁能；另外，现在使用的圆环线圈并非最优，D形线圈优于圆环线圈。     

Ultrasonographic assessment of human skeletal muscle size

The measurement of human muscle size is essential when assessing the effects of training, disuse and ageing. The considered gold standard for cross-sectional area measurements of muscle size is magnetic resonance imaging (MRI). However, MRI is costly and often inaccessible. The aim of the present study was to test the reproducibility and validity of a more accessible alternative method using ultrasonography (ULT). We examined the cross-sectional areas in the vastus lateralis muscle of six individuals. Axial-plane ULT scans were taken at given levels along the entire muscle length. The ULT scanning was repeated on different days (reliability) and validated against MRI-based measurements. Mean intraclass correlation coefficients were 0.998 for the reliability of ULT and 0.999 for the validity of ULT against MRI. The coefficient of variation values for cross-sectional area measurements assessed by six different experimenters were 2.1% and 0.8% for images obtained with ULT and MRI, respectively. The ULT method is a valid and reliable alternative tool for assessing cross-sectional areas of large individual human muscles. The present findings justify the application of the ULT method for the detection of changes throughout large muscles in response to training, disuse or as a consequence of sarcopenia.     

Magnetic resonance imaging of femoral head development in roentgenographically normal patients

Magnetic resonance images (MRI) of 22 patients with roentgenographically normal hips were reviewed retrospectively and the findings categorized according to age. With increasing maturity, the MR intensity of the femoral heads on spin echo images increased, as marrow fat became a dominant tissue in the head. The femoral head pattern was relatively inhomogeneous, with a broad band of diminished intensity extending in a posteromedial to anterolateral direction, corresponding to the pattern of trabecular bone. The femoral capital epiphyses were visible in younger patients as structures of bright intensity which remained evident through early adulthood. The articular cartilage of the hip joint was noted as a distinctive halo around the femoral head. An understanding of the MR pattern of the normal hip will aid in the early recognition of pathologic conditions, such as osteonecrosis.     

Remote metabolic effects of cerebrovascular lesions: magnetic resonance and positron tomography imaging

Summary Combined Positron Emission Tomography (PET) and Proton Magnetic Resonance Imaging (MRI) study were performed in six patients with chronic supratentorial stroke to investigate whether remote hypometabolic regions revealed by PET showed any abnormality on MRI. Either regional oxygen consumption (n=4) or glucose utilization (n=2) were measured using PET and the ¹⁵O steady state ¹⁸FGD technique, respectively. Four patients, with deeply located brain lesions, showed a significant metabolic reduction in the overlying cerebral cortex. In the remaining two patients, affected by a large cortical infarct, there was a significant crossed cerebellar hypometabolism. The MRI weighted by the parameters spin density (), spin lattice (T₁) and spin-spin (T₂) relaxation times were obtained employing various sequences in the same subjects. In no patient did the MRI show any contrast modification in these hypometabolic remote regions, suggesting that subtle loss of tissue and/or biochemical change do not underlie the reduction in metabolic rate.     

亚急性联合变性的临床分析

目的探讨亚急性联合变性(SCD)的临床特点、发病机制及电生理和磁共振成像的诊断价值.方法对14例SCD患者的临床资料进行回顾性分析.结果发现所有SCD患者发病均由维生素B12缺乏所引起.肢体感觉异常,深感觉减退,共济失调及痉挛性轻瘫是SCD常见的症状和体征.该病早期易误诊,电生理检查有极高的敏感性,磁共振成像可以确定脱髓鞘的部位.结论血清维生素B12浓度测定,体感诱发电位及磁共振对诊断和治疗有重要作用.