脑星形细胞肿瘤的MR灌注成像和病理分级对照研究

目的研究MR灌注成像(PWI)在脑星形细胞肿瘤术前分级中的应用价值.方法对28例脑星形细胞肿瘤病人行MR PWI,低级别星形细胞瘤9例,间变型星形细胞瘤12例,胶质母细胞瘤7例.依次行常规MRI及MR PWI,首先得到信号强度-时间曲线,并合成相对脑血流容积(rCBV)图,计算出最大rCBV比率.结果三组最大rCBV比率分别为(3.23±0.97), (5.23±0.33),(6.09±0.70),三组之间比较均有显著性差异.结论 MR PWI能有效地在术前评价星形细胞肿瘤的病理级别.     

法洛四联症的MRI诊断研究

目的评价MRI 对TOF的诊断价值.方法对20例临床疑诊为TOF患者进行MRI检查,分析其心内畸形和合并心外畸形的MRI表现.并与UCG表现进行比较.结果全部病例经手术证实,MRI能检出TOF心内畸形和合并心外畸形,统计学显示TOF心内畸形的MRI和USG检出率χ2值为1.03～2.01,P＞0.05,表明两种检查技术无显著差异;对合并心外畸形的显示,MRI明显优于UCG(χ2 = 52.27,P＜0.001). 结论 MRI有诸多的成像优势,能充分满足临床的诊断需求,是一种非常有用的检查技术.     

无静脉预饱和3D-TOF-MRA诊断脑动静脉畸形的临床应用

目的：评估3.0T MRI机无静脉预饱和三维时飞法MR血管成像（non-S-3D-TOF-MRA）在脑动静脉畸形（AVM）诊断中的临床应用价值。方法：回顾性分析40例临床疑似AVM患者进行无静脉预饱和3D-TOF-MRA、有静脉预饱和（S）3D-TOF-MRA、3D-PC-MRA及数字减影血管造影（DSA）检查的影像显示效果。结果：与DSA金标准相比,检出AVM瘤灶及显示供血动脉及引流静脉及汇入静脉窦non-S-3D-TOF-MRA、S-3D-TOF-MRA与DSA完全一致（100%）。结论：无静脉预饱和3D-TOF-MRA可全面准确地诊断AVM。     

磁共振PROSET序列在腰脊神经根成像中的临床应用价值

目的：探讨磁共振选择性激励技术（PROSET）序列对腰脊神经根显示及病变诊断的价值。方法：用3.0T超高场MRI仪,对健康对照组70例及病例组43例行腰椎MRI常规序列（T1WI、T2WI）、PROSET序列及磁共振脊髓造影（MRM）序列扫描,PROSET用＂肥皂泡＂软件行神经根曲面容积重组,MRM行MIP重组。由2位教授级MRI诊断医师分析和比较3种方法显示腰脊神经根长度及病变的影像表现,评价PROSET的应用价值。结果：2位MRI诊断医师达成一致意见的结果,即PROSET显示腰脊神经根长度达节后段,MRM未显示节后段,差异有统计学意义（P〈0.05）。PROSET与常规MRI诊断腰椎间盘突出（LDH）差异无统计学意义,但PROSET显示神经根鞘受压移位、神经根病变及与神经根关系的全貌。＂Soap Bubble＂后处理PROSET图像在一帧图像上显示神经根走形全貌。结论：PROSET序列能诊断神经根病变,且图像质量优于MRM,是常规MRI的重要补充;＂Soap Bubble＂后处理图像可提供直观的解剖形态信息。     

实验猪胸部正位CR合理曝光条件研究

目的探讨计算机X线摄影(computed radiography,CR)的合理曝光条件。材料与方法以10mAs、20mAs、40mAs档,分别从50～150kV、步长为2kV对实验猪胸部进行系列曝光,用剂量计记录每次曝光的入射点的入射X线剂量、肺野和纵隔处的透射X线剂量,得到三个序列的X线剂量与kV的关系数据,绘制入射剂量、透射剂量与kV的关系图,然后用相同的步骤进行系列胸部正位CR摄影,以噪声不影响观察为前提,找出曝光量最低的CR图像及其对应的合理曝光剂量,分析合理曝光剂量与曝光条件的关系。结果(1)合理曝光条件对透射剂量有很强的依从关系,不管如何改变kV和mAs的组合,合理透射剂量均是一个相对的恒定值,三个序列间合理剂量差异性比较均无统计学意义(P>0.05);(2)合理曝光剂量相对应的入射剂量,低mAs高kV组合要比高mAs低kV组合的入射剂量低,三个序列间差异比较具有统计学意义(P<0.01);(3)入射点剂量与mAs呈正相关。结论(1)对于CR来说,透射剂量是合理曝光条件唯一考量的参数;(2)提高kV对降低患者辐射剂量有意义。     

眼眶淋巴瘤的影像学特征与病理对比分析

目的 分析眼眶淋巴瘤(orbital lymphoma)的CT及MRI表现特征,探讨其影像学诊断的价值.方法 回顾分析9例淋巴瘤患者的CT及MRI所见,并与病理结果相对照,其中7例行CT扫描,4例行MRI扫描.结果 均为单侧发病,其中右眶7例,左眶2例;部位以隔前眶周、外上象限多见;其中2例为局限性肿块影,呈条索状或结节状,边界清楚,密度(信号)均匀,其余为弥漫性肿块,多沿肌锥外间隙及眼环向眶内呈"铸型"浸润生长,与周围组织关系紧密.增强扫描病灶呈中度及以上均匀强化.结论 眼眶淋巴瘤的CT、MRI表现具有一定的特征性,尤其是MRI检查能准确定位及一定程度的定性,有助于临床治疗.     

磁共振扩散加权成像与慢性乙型肝炎肝功能的相关性研究

目的 探讨磁共振扩散加权成像评价慢性乙型肝炎病人肝功能的应用价值.方法 对30例正常志愿者及30例慢性肝病病人行肝脏磁共振扩散加权成像,测量并比较正常组与病例组间肝实质表观扩散系数(apparent diffusion coefficient,ADC)值,分析ADC值与肝功能终末期肝病模型(model for end-stage liver disease,MELD)评分的相关性.结果 病例组ADC值较正常组降低(P<0.01),b=800 s/mm2时,ADC值与MELD评分有显著性负相关,r=-0.68,P<0.01.结论 肝实质ADC值与MELD评分显著性负相关,对慢性乙型肝炎肝功能的评估有较高的临床应用价值.     

常规MRI和1H-MRS在职业性锰暴露致中枢神经损害中的应用价值

Objective MRI and MR hydrogen proton spectroscopy (1H-MRS) were used to detect the abnormal signal and alteration of metabolites, in order to explore the efficacy of these method in evaluating the damages of central nervous system (CNS) induced by occupational manganese exposure.Methods Eighteen workers exposed to manganese without any manganism symptoms, 12 workers with slightly chronic manganese poisoning, and 19 healthy workers were scanned using routine MRI sequence and 1H-MRS.The blood manganese concentration was also collected for each subject.On cerebral axial T1 WI,the signal intensities of ipsilateral globus pallidus and frontal white matter were measured in the visually brightest area (try to select the signal homogeneous region), and the globus pallidus index (PI) was then calculated.The 1H-MRS data was calculated to get the values of the peak height of N-acetylaspartate (NAA), choline (Cho), inositol (mI) and creatine (Cr) and the ratios of NAA/Cr, Cho/Cr, and mL/Cr were also calculated.One way ANOVA was used to compare the values of PI, NAA/Cr, Cho/Cr, mI/Cr and MnB among the three groups, and the correlations between PI and the time span of manganese exposure or blood manganese concentration were analyzed by Pearson correlation analysis.Eight workers exposed to manganese were followed up one year, and their PI , NAA/Cr before and after follow-up were compared by t test.Results Fourteen of 18 cases exposed to manganese without any manganism symptoms showed symmetrically high intensity signal on T1 WI, while the T2 WI were normal.No high signal intensity was observed on T1WI in any of the healthy workers or manganese poisoning workers.We found that the average PI in manganese exposed group (1.16 ±0.09) was significantly higher (F =24.79 ,P =0.O00)than those of the poisoning ( 1.05 ± 0.07 ) and control groups ( 1.01 ± 0.05 ).The blood manganese concentration in manganese exposed group, the poisoning group and the control group were (0.051 ±0.024), (0.047 ±0.018 ), ( 0.043 ± 0.020 ) μg/ml respectively, which was not significantly different ( F = O.623, P =0.541 ) and did not exceed the upper limit of normal reference value ( < 0.10 μg/ml ).There was a significantly correlation between PI and the time span of manganese exposure ( r = 0.67, P = 0.002 ),however, there was no correlation between PI and blood manganese concentration ( r = 0.20, P = 0.427 ).Furthermore, the NAA/Cr ratio decreased variously in the manganese poisoning group ( 1.22 ± 0.07 ) which was significantly lower( F = 4.120, P = 0.023 ) than those of the poisoning( 1.33 ± 0.13 ) and control groups ( 1.31 ±0.13).No statistical significanees were found in the ratios of Cho/Cr and mI/Cr among these three groups(P>0.05).No obvious changes of the PI and NAA/Cr were found in the 8 manganese exposed workers after 1 year follow-up.Conclusion Manganese exposure could lead to the high intensity signal on T1 WI, therefore the increased PI may be the biomarkers of central nerve system damages caused by the occupational manganese exposure.     

全心冠状动脉磁共振成像初步探讨

目的：探讨自由呼吸导航全心冠状动脉磁共振成像（CMRA）心率对成像效果的影响。方法：对28例正常者,用自由呼吸导航触发3D-TFE序列行全心冠状动脉成像,用＂Soap Bubble＂软件进行冠状动脉曲面重建;以显示冠状动脉的节段数及图像质量为评价指标,分析比较不同心率对成像效果的影响。结果：28例中显示冠状动脉112支208段。不同心率冠状动脉显示节段数差异有统计学意义,当心率〈70次/min时各支冠状动脉主干近、中、远段均可良好显示。图像质量一级17例,二级5例,三级3例,四级2例,五级1例。不同心率的图像质量差异有统计学意义（P〈0.05）,当心率〈70次/min时图像质量较好。结论：自由呼吸导航全心CMRA的成像效果与心率有关,心率慢时,冠状动脉各支、段显示较完整,图像质量也较好。     

组织四维动态增强磁共振成像灌注参数与肝癌微血管密度相关性研究

目的 探讨组织四维动态增强(tissue 4 dimensional-dynamic contrast enhanced,T4D-DCE)磁共振成像(MRI)灌注参数在评估原发性肝癌(primary liver cancer,PLC)微血管密度(microvessel density,MVD)中的价值.方法 51例PLC患者行T4D-DCE MRI成像,并用Tissue-4D软件分析病灶和正常肝组织的灌注参数:转运常数(Ktrans)、血管外细胞外间隙体积百分比(Ve)、速率常数(Kep),将病灶灌注参数和正常肝组织灌注参数的比值作为病灶相对灌注参数与病理结果进行对比.结果 各灌注参数与PLC病理等级均无相关性(P＞0.05).Ktrans病灶、Ktrans相对、Kep相对与MVD均存在正相关(r=0533、0.791、0.717,P＜0.001).结论 T4D-DCE能直观反映PLC的血流灌注信息,在诊断PLC及评估PLC微循环特征中具有重要参考价值.