顺磁性对比剂Gd-DTPA对短暂性脑缺血发作1H MRS的影响

目的:分析短暂性脑缺血发作(TIA)患者MR脑灌注成像(PWI)后顺磁性对比剂钆喷酸葡甲胺(Gd DTPA)对质子磁共振波谱(1H MRS)的影响,探讨用PWI检查指导1H MRS定位的可行性.方法:对20例临床诊断为TIA的患者行PWI检查,分别在PWI检查前后于双侧半卵圆中心行1H MRS检查,扫描参数及兴趣区(VOI)均相同.对比分析注射Gd-DTPA前后两次1H MRS主要代谢产物氮-乙酰天门冬氨酸(NAA)、胆碱复合物(Cho)和肌酸复合物(Cr)谱线的形态(峰高和半高宽)及相对浓度值(峰下面积比值).结果:注射Gd-DTPA前后两次1H MRS检查NAA、Cho和Cr谱线的形态未发现明显改变,同一区域代谢物谱线的各项参数差异均无显著性意义(P＞0.05).结论:TIA患者PWI检查注射顺磁性对比剂Gd-DTPA对1H MRS没有明显影响,可以通过PWI显示的灌注异常,指导TIA患者的1H MRS定位.     

磁共振钆类对比剂对扩散加权成像的影响

目前 MR 检查中的常用序列包括增强扫描和扩散加权成像(diffusion-weighted imaging,DWI),在增强扫描中临床最常用的 MR 对比剂为钆类对比剂,其常规用于 MR 普通增强扫描、灌注加权成像(perfusion weighted imaging,PWI)、对比增强 MR 血管成像(contrast enhanced MRA,CE-MRA)等。DWI 近些年来在临床扫描中应用广泛[1],而表观扩散系数(apparent diffusion coefficient,ADC)值是 DWI 中的重要量化参数,DWI 通常在增强扫描前完成,但作为常规序列的补充序列,临床工作中有时会遇到需要在增强扫描完成后进行 DWI 扫描的情况[2],例如：在增强完成后才发现病变而希望增加 DWI 序列以提供更多鉴别诊断信息,一些序列设计中为获得足够的延迟扫描时间需要将增强扫描前置,如此也可以节省整体扫描时间等。因此,要确保临床扫描的序列设计方案,以及依赖 ADC 值进行计算得出的研究结果是否可信,必须首先明确钆类对比剂是否影响 DWI,特别是对DWI 中极为重要的量化指标 ADC 存在何种程度的影响。本文仅针对较常应用在临床中的钆类对比剂钆喷酸葡胺(Gd-DTPA)和钆塞酸二钠(Gd-EOB-DTPA)做一综述。     

不同剂型MR造影剂在肝脏病变增强扫描中的应用

顺磁性MR造影剂,钆喷酸葡胺(Gd-DTPA)已广泛应用于MRI的各项检查,有效地提高了MRI的诊断水平。钆双胺MR造影剂(GD-DTPA-BMA)是一种非离子型的二乙烯三胺五乙酸二甲胺的钆螯合物。其安全性和在中枢神经系统MRI检查中的有效性国外已有报道[1]。本研究旨在比较GD-DTPA-BMA和GD-DTPA在肝脏病变增强扫描中的增强效果。1对象和方法1.1对象随机选择2000年8月～2002年5月肝脏增强扫描患者60例,其中男32例,女28例,年龄33～76岁,均无心脑肝肾功能衰竭。随机分两组,第一组:30例(男女各15例),年龄33～70岁,平均50.26岁,采用非离子型钆…     

磁共振分子成像脂质体探针的制备与表征

目的:制备一种磁共振分子成像探针-钆结合空间稳定脂质体(Gd-SLs),并评价其物理属性.方法:利用挤出法制备空间稳定脂质体,表征脂质体粒径、稳定性、钆含量、弛豫率以及体外MR成像特点.结果:所制备之钆结合空间稳定脂质体经高压均质仪过膜后粒径控制于117.4±31.8nm;脂质体Gd载药率达87％～100％;常温下(26℃)Gd-SLs磁共振弛豫率为Gd-DTPA的1.16倍,37℃为1.25倍;体外MR成像显示Gd-SLs与Gd-DTPA两对比剂磁共振T1加权成像作用接近.结论:顺磁性空间稳定脂质体能有效提高磁共振分子探针体内成像信号,制备方法简单,实验操作可控性好,在一定温度范围内性质稳定,具有较高的磁共振弛豫作用,是理想的磁共振分子影像学对比剂载体.     

肝脏肿瘤手推团注动态MR增强扫描方法及2种对比剂效果比较

目的介绍肝脏病变手推团注动态MR增强扫描方法,对比离子型钆喷酸葡胺和非离子型钆双胺MR对比剂在肝脏肿瘤性病变动态增强的效果。方法185例肝脏肿瘤患者分2组:第1组91例(男52例,女39例),采用非离子型钆双胺MR对比剂(Gd-DTPA-BMA);第2组94例(男55例,女39例),采用离子型钆喷酸葡胺MR对比剂(Gd-DTPA)。行手推团注动态MR增强扫描。结果①手推团注动态强化效果总满意率75.14%,一般率24.32%,差0.54%。②2组间动态强化效果t检验无显著性差异,P>0.05。③各类肝脏肿瘤动态强化表现组间t检验无显著性差异,P>0.05。结论肝肿瘤手推团注动态MR增强扫描,Gd-DTPA-BMA和Gd-DTPA均可达到满意的增强效果。完全可满足临床诊断要求。     

钆类和氧化铁类MR对比剂在诊断急性脑梗塞中的应用

近十年MR对比剂的发展迅猛,开发了多种顺磁性和超顺磁性对比剂。对比剂的应用进一步拓宽了影像学技术的检查范围的广度和深度,尤其是对超急性期缺血性脑梗塞诊断。本文主要简述与缺血性脑梗塞MR诊断有关的钆类和超顺磁性氧化铁类对比剂的进展概况,和不同MR检查方法诊断缺血性脑梗塞的原理。     

Gd—DTPA—MR增强剂及其在脑疾病的应用

Gd-DTPA(Gadolinium-Diethylenetriaminepentaacetic Acid,钆-二乙三胺五乙酸)是第一个应用于临床的静脉内顺磁性MR增强剂,通过改变局部磁场环境,缩短周围氢核弛豫时间(主要是T_1时间)产生强化作用。该药稳定性好,副作用少。因Gd-DTPA不能通过完整的血脑屏障,从而使其成为颅内识别血脑屏障完整性的标记物,从而提高颅脑疾病检出率和定性诊断率。     

磁共振顺磁性对比剂(Gd-DTPA)对1H-MRS影响的分析

目的 探讨顺磁性对比剂钆-二乙烯五胺乙酸(Gd-DTPA)对氢质子波谱(1H-MRS)结果的影响.方法 对26例颅内肿瘤、17例非肿瘤性病变及15例健康者,分别于增强前后对同一层面同一兴趣区(ROI)行1H-MRS检查.比较增强前后氮-乙酰天门冬氨酸(NAA)、肌酸(Cr) 和胆碱复合物(Cho)的峰下面积及 Cho/Cr、Cho/NAA比值,应用配对t检验分析增强前后各主要代谢物之间的差异.结果 肿瘤组、非肿瘤组及正常对照组增强前后NAA、Cho、Cr峰下面积及Cho/Cr、Cho/NAA峰下面积比值差异均无统计学意义(P值均＞0.05).结论 顺磁性对比剂Gd-DTPA对1H-MRS结果分析不产生显著影响.     

超顺磁性氧化铁纳米粒子在细胞标记及细胞成像中的应用

近10年来,细胞成像技术是一个快速发展的领域,其目的在于可视化活体内靶细胞,获得细胞在活体内的生物学分布及迁徙情况。细胞成像作为一种活体内细胞监测的技术具有非侵人性及可重复性的特点。MRI由于其高分辨率的优点,可以达到细胞水平,所以成为细胞成像中的研究热点。靶细胞必须经MR对比剂标记后才能区别于背景组织而被MR监测到,目前常用的MR对比剂为钆类及氧化铁类。钆类对比剂具有低弛豫率、细胞清除快、非生物相容性等缺点,且去螯合化后对细胞的毒性作用目前知道的很少。氧化铁类中的超顺磁性氧化铁纳米（SPIO）材料是继钆之后一种新的用于MR对比剂的材料。     

含钆对比剂在脑血管DSA介入检查或治疗中的应用

目的:探讨Gd-DTPA作为对比剂在脑血管DSA介入检查或治疗中的应用价值。方法:对28例碘剂禁用者应用钆喷酸葡胺作为对比剂进行脑血管DSA介入检查或治疗,另外随机抽取28例应用非离子型碘水对比剂作为对照组进行脑血管DSA介入检查或治疗。两组病例对比剂的注射量、注射流率及压力限制保护均相同,通过对相关血管DSA图像显示结果进行对照分析,揭示含钆对比剂在脑血管DSA介入检查或治疗中的应用价值,寻求改善钆对比剂脑血管DSA图像质量的途径。结果:应用Gd-DTPA作为对比剂进行脑血管DSA介入检查或治疗,与应用非离子型碘水对比剂相比较,由于含钆对比剂的钆离子浓度低,其图像质量略差于使用非离子碘水对比剂图像,脑部相关血管主干显示无明显差异,对于终末细小分枝的显示,碘水对比剂影像质量优于含钆对比剂。通过以下措施来改善影像质量,从而获得满意图像:①改变图像采集时DSA设备的管电压值:将应用碘水对比剂时的66～70kV提高到75～80kV;②调整窗宽、窗位数值:将窗宽值由930降至900,将窗位值由50升至75,提高图像的对比度和降低图像亮度;③调整图像滤过参数、边缘增强指数:提高滤过参数至100%;边缘增强指数由4升至5。结论:在对碘剂禁用者中使用Gd-DTPA进行脑血管DSA介入检查或治疗,能够显示脑部相关血管影像,可以满足脑血管病的诊断及介入治疗需要。     

Optimization of the system of medical service of students of Cadet Schools of the Ministry of Defense of the Russian Federation

One of the factors of the successful military career guidance Cadet schools students is preserving and promoting their health. Medical support of children and adolescents aged 10-17 years should include the full range of medical and preventive measures defined for this group. The state of providing outpatient care for pupils at the Cadet School in St. Petersburg was studied. These results show that full medical care in accordance with the standards can be based only on children's health clinics. It is important that the organization of medical support pupils cadet schools should be cooperate with civilian health care.     

带状疱疹83例误诊原因分析

带状疱疹是由水痘—带状疱疾病毒引起的皮肤科常见疾病。其主要的病理损害,一是受累神经的严重炎症性浸润,继而导致受侵犯神经节内神经细胞变性、坏死;二是皮肤的水泡。迅速抑制神经节和相应的感觉神经纤维的充血、水肿和坏死,防止粘连形成,达到迅速镇痛、改善皮损,缩短病程及防止后遗症的发生是治疗的关键。因而,尽早明确诊断,     

Estimation of accumulated dose of radiation by method of ESR-spectrometry of dental enamel of mammals

ESR-spectrometry was used to investigate radiation-induced paramagnetic centers in enamel of mammals: carnivores (polar bear and fox), ungulates (reindeer, European bison, moose), and man. Values at half the microwave power saturation of the radiation signal, P_1/2, evaluated at room temperature, was found to range from 16 to 26 mW for animals and man. A new approach to discrimination of the radiation induced signal from the total ESR spectrum of reindeer enamel is proposed. ‘Dose-response’ dependencies of enamel of different species mammals were measured within the dose range from 0.48 up to 10.08 Gy. Estimations of ‘radiosensitivity’ enamel of carnivores and ungulates showed good agreement with radiosensitivity enamel of man by ESR method.     

Analysis of the results of the international comparison of activity measurements of a solution of Fe

The results of an international comparison of activity measurements of a solution of ⁵⁵Fe organized by the BIPM in 2005 are reported and analysed. This exercise, which follows the procedures of the CIPM mutual recognition arrangement to update older comparisons, is a renewal of the comparison organized by the BIPM that took place in 1978. A EUROMET comparison was organized in 1996 specifically to compare activity measurements of a ⁵⁵Fe solution by means of liquid-scintillation techniques. Results of these three comparisons are presented and discussed in this paper.

The radionuclide solution was provided by the NPL, which also distributed the samples to the participants. The activity of the ampoules was measured by 16 laboratories using 12 methods producing 25 results. Some general considerations on uncertainty assessments pertaining to the different techniques used are drawn. The outcome of four different estimators is compared from which the presence of at least one outlier can be confirmed. Further measurements should be made to try to reduce the discrepancy between the results. To date the outcome of the present comparison does not show an improvement to that of the 1996 comparison.     

Evaluation of the results of various technics of non-surgical therapy of varicocele

A new method of non-surgical treatment of varicocele syndrome is described: it consists in sclerotherapy of spermatic vein by trans-femoral percutaneous catheterization with balloon-catheters. In 8 cases venous thrombosis has been induced by direct electric clotting. The techniques and a 6 months follow-up are discussed. It is pointed out that this procedure should be considered as the method of choice for tubular lesions and sub-fertility prophylaxis in young people and in childhood.     

延迟性脾破裂误漏诊原因分析

目的探讨延迟性脾破裂误漏诊原因和预防措施.方法回顾性分析总结12例延迟性脾破裂中的诊断和误漏诊的经验与教训.结果本组延迟性脾破裂的误漏诊5例(41.66%).对多发伤与脾破裂并存可能认识不足,外伤史轻微或伤员隐瞒外伤史,缺乏腹痛-缓解-突然再腹痛的典型病史,缺乏“对冲性脾破裂”力学分析和整体化诊断思路等为其误漏诊的主要原因.结论详细的外伤史和全面系统检查,重视腹以外多发伤掩盖腹内脏器伤及延迟性脾破裂可能.确立外伤-腹内脏器伤-脾破裂整体化诊断思路.不间断地辅以B超检查脾形态学变化和腹内有无积液,腹腔穿刺确定有无血腹、X线胸腹部检查观察左侧胸肋角和膈肌运动情况、必要时CT检查以尽早发现脾包膜下血肿,降低延迟性脾破裂误漏诊率.