CT对比剂肾病的认识和预防

<正>CT成像的先决条件是组织间的密度差异,为增加这种差异,多数情况下需行增强扫描。随着CT的普及,CT增强扫描的安全性愈来愈受到关注。如何降低对比剂的肾毒性、避免对比剂肾病(contrast induced nephropathy,CIN)的发生,以及如何为肾功能不全患者选择合适的对比剂等都需进一步研究。1对比剂的定义及特性对比剂是为增强影像观察效果而注入(服用)到     

双能CT虚拟平扫对肾脏病变定性的影响

正摘要双能(DE)CT可从单时相对比剂CT增强检查中重建虚拟非对比剂(VNC)影像,这样可能减少多时相CT增强对肾脏病变定性的需求。然而,关于VNC影像用于诊断肾     

肺动脉CT成像增强技术的优化研究

目的 推导CT肺动脉成像(CTPA)中精确计算对比剂用量公式,并评价其应用于小剂量对比剂预注射法CTPA影像的质量与临床应用的意义.方法 搜集经CTPA检查的连续27例患者小剂量对比剂实验注射形成的TDC数据,分析从注射对比剂开始至上腔静脉下端增强峰值所用时间占注射开始至肺动脉增强峰值时间的比值,测算上腔静脉下端在扫描范围中的水平,推导出计算对比剂使用总量预计算公式( DTs/3+ STs/2).将临床怀疑但CTPA未发现为肺动脉栓塞(PE)的68例患者纳入研究,按检查奇、偶周数分为2组:A组26例,传统增强跟踪自动触发扫描组;B组42例,小剂量对比剂预注射组.在CTPA影像中,2组分别测量右肺动脉主干(RMPA)和右上肺静脉(RUPV)、右肺下叶后基底段动脉(RLPA)和伴行右下肺静脉(RLPV)、RMPA与升主动脉(AA)的CT值,计算每对血管CT值差值,对影像进行评分,并计算对比剂用量、上腔静脉内对比剂硬化伪影分级.采用f检验、x2检验与秩和U检验,分析2组间各值差异的统计学意义.结果 对比剂开始至注射到上腔静脉增强时间与至肺动脉增强时间比为0.65±0.09.A、B2组间RMPA、RLPA的CT值分别为(301±117)、(329±122)与(283±95)、(277±98)HU,差异无统计学意义(t值分别为1.060、2.056,P值均＞0.05),但肺动静脉血管对之间的CT值差(中位数分别为22.5、58.0与170.5、166.5 HU),2组间差异有统计学意义(U=292,P=0.001与U=325,P=0.005);影像评分为5分与4分者B组为85.7％( 36/42)优于A组(46.1％,12/26),差异有统计学意义(x2=14.175,P＜0.01);上腔静脉内对比剂伪影分级(1～3级)B组(分别为34、7、1例)明显好于A组(分别为11、10、5例),差异有统计学意义(x2=10.714,P=0.002);对比剂实际注射总量A组为(87.6±7.3)ml,B组为(40.0±5.4) ml,差异有统计学意义(t=-2.152,P＜0.01).结论 采用小剂量对比剂预注射法与传统方法比较,CTPA影像质量与强化程度一致,但可明显降低肺静脉内对比剂的浓度,对肺动脉的辨识更容易,而且可明显减少上腔静脉内对比剂的硬化伪影对右肺动脉观察的干扰,降低对比剂的用量,有利于减轻患者对比剂肾病的危险.     

离子型和非离子型MR对比剂在MR颈动脉动态增强中的应用

目的:探讨离子型和非离子型MR对比剂在MR颈动脉动态增强扫描中的应用价值。材料和方法:将2005-09~2006-06行颈动脉动态增强扫描的56例患者,随机分为A、B两组。A组28例,用离子型对比剂(Gd-DTPA),B组28例采用非离子型对比剂(Gd-DTPA-BMA)。用3.0TMR机行动态增强扫描。A、B两组的扫描参数相同。结果:56例均完成颈动脉动态增强扫描。两种对比剂的增强效果无明显差异(P>0.05)。两组对比剂不良反应中,A组1例出现恶心,B组1例出现发热症状的轻微不良反应外,两种对比剂在使用的安全性上无差异。结论:两种对比剂的增强效果及使用安全性无明显差异,非离子型对比剂是MR血管造影动态增强较为理想的对比剂。     

CT肺动脉成像在剂量优化方面的研究进展

<正>CT肺动脉成像(computed tomography pulmonary angiography, CTPA)是指在外周静脉注射一定容积的含碘对比剂,当对比剂充盈于肺动脉时,利用CT设备对其进行扫描以生成肺部血管的增强扫描影像。CTPA可以充分显示肺动脉至亚节段水平^[1],是临床上诊断肺动脉病变最常用、最直接的影像检查方法。然而,该检查会带来电离辐射,尽管没有充分证据表明电离辐射会直接引发恶性肿瘤,但是仍然有致癌风险^[2]。     

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。     

颅内静脉系统的时间分辨MR血管成像:另外一种MR静脉成像技术

正摘要目的对照对比剂动力学时间分辨影像(TRICKS)MR血管成像(MRA)与二维时间飞跃(TOF)MR静脉成像(MRV)、三维对比增强(CE)MRV正常脑静脉与硬膜静脉窦的影像显示。方法35例连续病人纳入本前瞻性研究。所有病人均接受TOF MRV、TRICKS MRA与CE MRV检查;单一剂量静脉对比剂注射用于后     

CT碘剂延迟增强结合影像减影技术评估心肌梗死

正摘要目的探讨CT碘剂延迟增强(LIE-CT)结合影像减影技术在心肌梗死(MI)评估中的可行性。方法应用心脏CT综合扫描方案和MRI钆剂延迟增强(LGE-MRI)评估27     

不同碘浓度对比剂在肾脏MSCT增强扫描中的作用对比

目的:探讨300mgI/ml对比剂与400mgI/ml对比剂对肾脏MSCT多期增强扫描的强化作用。方法:将40例疑肾脏病变的患者随机分成两组,每组20例,分别行肾脏平扫及给予碘必乐300(300mg I/ml)与碘迈伦400(400mg I/ml)的多期增强MSCT扫描。在对比剂开始注射后18s、30s、80s、3~5min扫描。测量各期增强扫描腹主动脉、双肾动脉、双肾静脉、双肾皮质、双肾髓质、双肾盂、肾脏病变的CT强化值。观察上述结构的强化情况。结果:使用400mgI/ml对比剂组在18s与30s采集,所检测的血管与肾各结构强化均值与300mgI/ml对比剂组相比,差异有显著性意义(P<0.01),80s采集,肾动脉、肾静脉、肾髓质强化均值与300mgI/ml对比剂组相比,差异有显著性意义(P<0.01),3~5min采集,肾静脉与肾盂强化均值与300mgI/ml对比剂组相比,差异有显著性意义(P<0.01)。结论:高碘浓度对比剂对肾血管的显示优于标准碘浓度对比剂,并可降低对比剂用量。肾脏MSCT高碘浓度对比剂增强扫描在对比剂开始注射后30s与延时3~5min采集较合理。     

CT血管成像静脉注射碘对比剂的原则和策略

随着CT技术的迅速进展,CT已经成为医学影像检查中非常重要的组成部分,而静脉注射对比剂增强的CT检查,尤其是CTA的普及更是增加了静脉注射碘对比剂的应用.在很多医疗机构,CTA已基本代替了常规DSA检查,成为血管性病变诊断首选的影像检查手段,甚至被认为可作为影像诊断的金标准[1].然而在临床实践中,新的CT设备也带来了新的问题和挑战.虽然当前CT快速的扫描能力使进行对比增强CT扫描时常可以获得足够诊断的图像质量,但在非常短的扫描时间内确保得到靶部位最大程度的强化却成为一个很大的临床问题,这对精确确定靶部位扫描延迟时间提出了更高要求.笔者综述当前CT静脉注射碘对比剂的一些原则和策略.     

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.