脑梗死在扩散加权像上信号强度及表面扩散系数变化的时间过程

目的 探讨脑梗死在扩散加权像（ｄｉｆｆｕｓｉｏｎ ｗｅｉｇｈｔｅｄ ｉｍａｇｉｎｇ,ＤＷＩ）上信号强度、表面扩散系数（ａｐｐａｒｅｎｔ ｄｉｆｆｕｓｉｏｎ ｃｏｅｆｆｉｃｉｅｎｔ,ＡＤＣ）变化的时间过程及两者的关系。方法 ５６例脑梗死病人计１０７个病灶接受ＭＲ ＤＷＩ检查,计算病变的信号强度比值（ｓｉｇｎａｌ ｉｎｔｅｎｓｉｔｙ ｒａｔｉｏ,ＳＲ）、ＡＤＣ及相对ＡＤＣ（ｒＡＤＣ）,根据ＤＷＩ和Ｔ２     

单激发厚层投射MR胰胆管成像及其应用价值

目的：探讨单激发厚层投射磁共振胰胆管成像（ＭＲＣＰ）显示胰胆管树的能力和对胰胆管梗阻性病变的诊断价值,材料与方法：用重Ｔ２加权单激发ＴＳＥ序列、厚层投身成像技术做ＭＲＣＰ检查共１５０例,正常组５０例,病变组１００例。分析其对正常胰胆管各主要结构的显示率及对梗阻病变的检出率、定位和定性诊断准确率,将结果与ＣＴ、ＵＳ、ＥＲＣＰ／ＰＴＣ及手术和病理相对照。结果：本法可显示管径１￣２ｍｍ的胰胆管分支;准确     

MR Features of Regenerative Nodules and Dysplastic Nodules in the Cirrhotic Liver

Summary： In order to study MR features of the regenerative nodule （RN） and dysplastic nodule （DN） of the cirrhotic liver, 26 cases of cirrhotic liver with RNs and DNs, of which 8 cases accompanied with hepatocellular carcinoma, were subjected to MRI. Eighteen of 26 cases underwent additional enhanced MRI with administration of Gd-DTPA on T1WI and 10 of the 18 cases did additional SPIO （Feridex） enhancement on T2W1. Clinical data showed normal level of α-fetoprotein in 18 cases except 8 cases accompanied with HCC. The results showed that 12 cases had RNs with nodules measuring 〈1 cm. The MR appearance of those RNs showed isointensity on T1WI and hypointensity on T2WI. The intensity of those RNs was isointense to the surrounding hepatic parenchyma on enhanced MRI with administration of Gd-DTPA or SPIO. Among the 14 cases of DNs, 8 cases had nodules measuring 1-3 cm in size and 6 had macroregenerative nodule measuring 〉3 cm. In 8 cases with DNs measuring 1-3 cm in size, 5 cases appeared hyperintense on T1W1 and hypointense on T2W1 as well as the enhancement as that of nodules with （1 cm in size; and the remaining 3 cases appeared hypointense on T1WI and hyperintense on T2WI, and were not isointense to the surrounding hepatic parenchyma on enhanced MRI but hyperintense on SPIO enhanced MRI. In 6 cases of macroregenerative nodule measuring 2〉3 cm in size, 2 cases appeared hyperintense to the surrounding hepatic parenchyma on T1, T2WI and enhanced MRI; 4 cases showed hyperintense on TlWI, and hypointense on T2WI and enhanced MRI. Sometimes, normal vessels were seen to pass through the surface of macroregenerative nodules. It was suggested that RNs of cirrhosis had features on MRI that usually allow distinction from hepatocellular carcinoma but not always from dysplastic nodules （DNs）. A helpful distinction between HCC and DNs is that the latter are almost never hyperintense on T2WI. Additionally, low grade DNs appear hypoimense on SPIO enhanced MR1.     

“双百灵”牌纯泛影葡胺CT造影剂临床使用报告

“双百灵”牌纯泛影葡胺ＣＴ造影剂临床使用报告孙树华，熊茵，曾祥阶＂双百灵＂牌纯泛影葡胺（湖南益阳制药厂生产，批号：９３．１１１６）．于１９９４年５～１０月间在我院用于ＣＴ增强扫描，现将使用情况报告如下：一、理化性能测试１．在临床使用之前，先将此药与国...     

MR相位速度图对椎动脉的血流动力学研究

目的 应用磁共振相位对比法,采用流动分析软件,通过测量椎动脉的流速、流量,评价正常及病理情况下椎动脉血流动力学改变及其意义。方法 测量了８你健康人和１８例椎动脉狭窄时的椎动脉血流变化。采用Ｋ－空间段电影相位速度对比法（Ｓｅｇｍｅｎｔｅｄ Ｋ－ｓｐａｃｅ ｃｉｎｅ ｐｈａｓｅ－ｃｏｎｔｒａｓｔ ＭＲ）测量椎动脉的流量率曲线图,运用统计学分析,比较椎动脉横截面积、流速、流量及其返流量变化情况。结果：Ｍ     

高场磁共振仪评估新生儿和婴儿的正常脑髓鞘

目的：应用高场ＭＲ仪研究正常小儿不同月龄段的脑髓鞘与对应ＭＲＩ信号特征。方法：５８例正常小儿在１．５Ｔ ＭＲ仪内行头部扫描。采用自旋回波（ＳＥ０和快速自旋回波（ＴＳＥ）序列,获取Ｔ１和Ｔ２架驻像,结果：（１）髓鞘形成中的ＭＲＩ信号变化,相对于灰质信号,未的髓鞘呈短Ｔ１和长Ｔ２,在Ｔ１ＷＩ上呈高信号与灰质易区别,在Ｔ２ＷＩ上与灰质信号相近;的髓鞘呈短Ｔ１和短Ｔ２;在Ｔ２ＷＩ上呈低信号,与灰质易区别;     

先天性子宫畸形的MRI诊断价值

目的探讨MRI对先天性子宫畸形的诊断价值。资料与方法回顾性分析8例先天性子宫畸形的MRI资料。结果单纯双子宫畸形2例,双子宫畸形伴阴道纵隔1例,双角子宫伴左侧卵巢囊肿1例,完全纵隔子宫2例,完全纵隔子宫伴阴道纵隔2例。结论MRI可以显示不同子宫畸形的官腔结构及宫底外观形态、各种复杂畸形及并发的其他病变,是诊断先天性子宫畸形的可靠方法。     

大鼠海洛因中毒性脑损害的实验研究

目的　探讨海洛因中毒性脑损害动物模型的建立方法 ,同时研究这种脑损害的病理改变及其发病机理。材料与方法　通过建立海洛因依赖及中毒性脑损害大鼠模型 ,观察其脑部光镜与电镜改变 ,总结这种脑损害的病理变化规律。结果　成功建立海洛因依赖及中毒性脑损害大鼠模型。海洛因中毒性脑损害大鼠光镜与电镜表现 :(1)大脑皮层神经细胞变性坏死 ,累加剂量 4 336mg/kg体重组与 1931mg/kg体重组或盐水对照组之间大脑皮层神经细胞死亡数的差别有显著性意义 (P =0 .0 2 4及P =0 .0 32 ,均P <0 .0 5 ) ;(2 )海马CA1 4区光镜下主要表现神经细胞固缩坏死 ,数量减少不明显 ;(3)小脑浦肯野细胞大量固缩变性 ,部分坏死及脱失 ;(4 )首次发现海洛因中毒大鼠大脑皮质微血管周围基质溶解破坏 ;(5 )大鼠大脑及小脑髓鞘轻度变性 ,但未见典型脱髓鞘改变。结论　建立海洛因依赖及中毒动物模型可以有效地研究海洛因对中枢神经系统的毒性损害。大鼠海洛因中毒性脑损害病理改变主要是多部位神经细胞变性坏死及微血管基质的溶解破坏。长期海洛因滥用引起大脑持续低氧状态及海洛因直接损害可能是两大主要原因     

The Value of In-Phase and Opposed-Phase T1-Weighted Breath-Hold FLASH Sequences for Hepatic Imaging

Tl--weighted(TlW)sequencesareconsideredtobeanintegralcomponentofacomprehensiveMRexaminationoftheliver.TheTlWSEsequenceiscurrentlyperformedinconventionalMRexaminationoftheliverfordetectionandcharacterizationoffocallesions.However,conventionalSEMRI-isproblem-aticdueto1ongdurationofdataacquisition(theor-derofminute)andphysicalmotionartifactscausedbyrespiratorymotionandgastrointestinalperistalsisandsoon.WithdeveIopmentofthehardwareandsoftwareoftheMRIsystem,theuseofGREtech-niqueshasbecomei…