带状灰质异位的磁共振弥散张量白质束成像研究

目的采用磁共振弥散张量白质束成像技术,观察带状灰质异位脑白质异常分布情况,探讨异位灰质的神经病理机制以及弥散张量白质束成像技术的应用价值。方法采用磁共振弥散张量白质束成像技术,对1例癫痫症状的带状灰质异位患者进行白质束描绘,观察其不同灰、白质的分布情况,并和1例正常人进行对比研究。结果弥散张量白质束成像技术很好地描绘了白质束结构。整体观察发现带状灰质异位患者脑白质整体结构紊乱,与正常人相比其联络弓状纤维稀疏、大部缺失,胼胝体纤维稀疏不整;局部分析发现内层灰质为主要的白质纤维发出处,而外层灰质仅发出细碎短小的纤维。结论对于带状灰质异位,异位的内层灰质不仅具有神经生理功能,并且可能起着主要作用,外层"正常"的灰质由于脑结构紊乱而丧失主要功能地位;灰质结构的紊乱导致白质纤维结构的缺失;弥散张量白质束成像技术可以很好地应用于带状灰质异位的神经机制研究。     

膝关节软骨退变的MRI检查与关节镜对照研究

目的明确三维梯度回波序列与脂肪抑制技术联合应用对关节软骨退变的诊断价值,并用关节镜检查结果作为标准进行对照研究. 资料与方法选择27例因外伤致半月板或韧带损伤需关节镜修复或关节镜下取游离体的患者作为研究对象.男18例,女9例,年龄27～70岁,平均56岁.所有病例均行膝关节MRI检查,检查序列包括SE T1WI、FE T2*WI、FS 3D RF-spoiled FAST.MRI检查后2周内行关节镜检查. 结果 FS 3D RF-spoiled FAST序列发现病变敏感性、特异性、准确性分别为90%、98%、96%,病变检出率及分级与关节镜结果比较无统计学显著性差异(P＞0.05). 结论三维梯度回波序列与脂肪抑制技术联合应用的T1WI是发现软骨退变的敏感序列.关节疼痛的患者行膝关节检查时,除常规MRI序列外,应加一软骨敏感序列.     

多房性囊性肾瘤的影像学表现与病理对照

目的 提高对多房性囊性肾瘤的影像学的认识。资料与方法 报告2例经手术病理证实，且临床与影像学资料完整的多房性囊性肾瘤。分析其B超、IVU、CT、MRI检查所见征象，并与手术、病理所见对照，结合文献复习，对多房性囊性肾瘤作深入讨论。结果 影像学表现为肾区单发、多房性囊性病灶；囊肿边界清楚，与肾盏不相通，肾脏被挤压变薄，未受累区的肾脏正常；囊内容均匀或不均匀；囊间隔的密度比正常肾实质低，分隔完全且厚薄不一，可强化，但强化程度不及正常的肾组织。术后病理证实为多房性囊性肾瘤。结论 CT、MRI最能反映多房性囊性肾瘤的病理基础，是术前诊断该病的最佳方法。术前完善的影像学检查对该病的治疗方案及预后至关重要。     

Identifying the affected hemisphere by 1H-MR spectroscopy in patients with temporal lobe epilepsy and no pathological findings in high resolution MRI

Up to 30% of patients with temporal lobe epilepsy (TLE) remain without remarkable changes in MRI. In this study we investigated the role of (1)H-MR spectroscopy ((1)H-MRS) in lateralizing the affected hemisphere in the mentioned patient group. Twenty-two consecutive patients diagnosed with TLE were investigated by high resolution MRI and (1)H-MRS. We examined the incidence and diagnostic accuracy of temporal metabolite alterations determined by Linear Combination of Model Spectra (L C Model) via water reference. Metabolite values of each hemisphere of TLE patients were compared with healthy controls. Results of metabolite alterations were related to intensive video EEG focus localization. Reduction of N-acetylaspartate + N-acetylaspartyl-glutamate (tNAA) in the affected hemisphere revealed identification in six of nine patients (66%) with unilateral TLE. Group comparison revealed a significant reduction of tNAA (6.1+/-0.8*) in the involved temporal lobe compared with controls (6.67+/-0.4*, P=0.026). Choline levels were significantly increased in the affected hemisphere (1.42+/-0.17*) compared with healthy controls (1.22+/-0.17*, P=0.035). The results of our study show that (1)H-MRS is able to identify the affected hemisphere of MRI negative TLE patients and can be used as an additive tool in multimodal focus localization.     

Novel ROC-type method for testing the efficiency of multivariate statistical methods in fMRI.

The receiver operating characteristic (ROC) method is a useful and popular tool for testing the efficiency of various diagnostic tests applicable to functional MRI (fMRI) data. Typically, the diagnostic tests are applied on simulated and pseudo-human fMRI data, and the area under the ROC curve is used as a measure of the efficiency of the diagnostic test. The effectiveness of such a method depends on how well the simulated data approximate the real data. For multivariate statistical methods, however, this technique is usually inadequate, as the spatial dependence among voxels is ignored for simulated data. In this work a modified ROC method using real fMRI data with a broader scope is proposed. This method can be applied to most fMRI postprocessing techniques, including multivariate analyses such as canonical correlation analysis (CCA). Also, the relationship of the modified ROC method with the conventional ROC method is discussed in detail.     

骨纤维异常增殖症生长方式的影像研究

目的 探讨骨纤维异常增殖症起始部位与生长方式。分析其影像学特异性征象。方法 对13例经手术病理证实的骨纤维异常增殖症之CT/MR影像进行回顾性分析并作献复习。结果 病灶成像以纤维组织为主多局限于皮质内生长；病灶成份以编织骨为主。易穿入髓腔弥漫生长。结论 病变起始骨皮质，按病理组织学不同成份。决定其生长方式。CT/MR影像显示起始部位与发展趋势，具有特殊定性诊断价值。     

股骨头缺血坏死的低场MRI评价

目的: 分析股骨头缺血坏死(ANFH)低场MRI征象,评价ANFH的MRI分期及其关节积液的分级.材料和方法:在分析50例正常髋MRI基础上回顾性对照分析51例(90个股骨头)ANFH的低场MRI和X线平片资料.结果:90个ANFH中,20个(22 %) X线平片为阴性;64个(71%)MRI示"脂肪强度征"即坏死区内或近侧可见类似皮下脂肪样信号.按照 Hungerford分期:0期9个,Ⅰ期13个,Ⅱ期31个,Ⅲ期26个,Ⅳ期11个.ANFH引起的关节积液多为2～3级(60个髋,占67%);Ⅲ、Ⅳ期ANFH合并关节积液量比0～Ⅱ期明显多(P＜0.005).结论:低场MRI能够准确显示ANFH的范围、程度、信号特征及其关节积液的情况,并能够对早期ANFH作出可靠诊断;"脂肪强度征"为低场MRI的特征性表现,对诊断ANFH有非常重要的价值.     

两种MRI序列对听神经瘤成象的比较与评价

为选择中等场强的ＭＲＩ听神经瘤成像最佳序列。收集手术和病理证实的听神经瘤１３５例，分析序列Ⅰ、Ⅱ对内听道中心层面、三叉神经显示率及ＭＲ征象的显示情况。结果：序列Ｉ择内听道中心层面及三叉神经的显示均优于序列Ⅱ，序列Ⅱ在显示肿瘤内囊变、出血、不肿优于序列Ｉ；对肿瘤钙化、肿瘤血管、脑干移位的观察，两者相仿。结果显示：序列Ｉ在中等场经下作为听神经瘤成像的首选序列，并中运用到小脑角区ＭＲＩ成像。     

Bacteroides fragilis Pyomyositis in a Patient with Multiple Myeloma

Pyomyositis is a bacterial infection with abscess formation affecting large skeletal muscles. It is predominantly caused by Staphylococcus aureus. The disease is common in tropical areas, but rare in temperate climates. We report a patient with multiple myeloma who developed a giant elastic tumor on the right thigh and a hen egg-sized tumor on the right upper arm. MR imaging revealed cystic spaces in the femoral quadriceps and brachial biceps muscles. A large amount of pus with foul smell was removed by incision, drainage and aspiration of the two tumors. The lesions were successfully treated with intravenous administration of antibiotics. Repeated bacterial cultures yielded only Bacteroids fragilis. To our knowledge, this is the first report of pyomyositis due to Bacteroides fragilis.     

Genetic susceptibility to herpetic encephalitis of inbred rabbits of B/Jas strain

Inbred rabbits of B/Jas strain were found to be highly susceptible to herpes simplex virus type 1 encephalitis, following i.v. injection of the virus, while Chbb:HM strain rabbits were not susceptible. The susceptibility trait seemed to be inherited recessively, involving multiple genes, because (B/Jas x Chbb:HM)Fl hybrids were as resistant as Chbb:HM rabbits, and because more than 90% of backcrosses of (B/Jas x Chbb: HM)FI to B/Jas were resistant to viral inoculation. The encephalitis in B/Jas rabbits resembled human herpes simplex encephalitis, in that the temporal lobe as well as the brain stem were affected preferentially, leading to the development of various types of seizures, such as circling, loss of balance leading to a fall, and tonic and clonic convulsions. The disease could be diagnosed by magnetic resonance imaging (MRI) analysis before onset of seizures, and diseased rabbits showed a marked lymphopenia at onset of seizures. © 1995 Wiley-Liss, Inc.