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。     

颈内动脉瘤DSA检查技术应用探讨

颈内动脉瘤是较常见的颅内血管性病变之一，脑血管造影是诊断该病必不可少的检查手段。随着DSA技术的广泛应用和神经介入治疗的发展，对其检查提出了更高的要求。不仅要求发现小的血管瘤，还必须明确血管瘤的部位以及与周围血管的关系和其血液循环的情况。本文通过对我院12例颈内血管瘤DSA检查技术应用的分析，探讨如何在检查中合理地综合运用DSA设备的方法。     

不同场强下部分DSA介入性器械伪影的探讨

目的 :探讨 0 .3T、1.5T场强下各种DSA介入性器械伪影的大小及其影响因素 ,评价各种介入性器械行MR检查的安全性以及进行MR介入操作的可行性。方法 :将胆管内支架、聚酯动脉化疗药盒、镍钛合金静脉化疗药盒、球囊、微导管等介入性器械置于模具中 ,在 0 .3T、1.5T场强下均行MR扫描 8次 ,观察比较各种介入性器械在两种不同场强下伪影的大小及其影响因素。结果 :胆管内支架在 0 .3T场强下显示比 1.5T更为清晰 ,两种场强下不同序列不同参数对其伪影无明显影响。聚酯动脉化疗药盒在两种场强下不同序列均无伪影。镍钛合金静脉化疗药盒在 0 .3T场强下伪影较小 ,在1.5T场强下伪影较大 ,但两者差异无显著性意义 (P >0 .0 5 )。各种导管在不同场强下无伪影。各种导丝在两种场强下伪影较明显。结论 :行胆管内支架、聚酯动脉化疗药盒、镍钛合金静脉化疗药盒等治疗后行低场强 (0 .3T)MR检查伪影极小 ,是安全可行的。聚酯动脉化疗药盒在 1.5T场强下无伪影 ,胆管内支架、镍钛合金静脉化疗药盒在 1.5T场强下伪影较小 ,但仍适合MR检查。各种导管在不同场强下均无伪影 ,在不同场强下行MR介入操作是安全可行的。     

腹部MR检查中口服对比剂的应用

腹部MR检查日趋广泛,然而缺乏理想的口服对比剂,这在很大程度上限制了MR技术在腹部的应用.综述了口服MR对比剂的作用原理、分类、服用方法及临床应用价值,以促进其研制和应用.     

胸腹部CT或DSA检查后对比剂向脑实质和脑脊液腔外渗

目的：对经静脉或动脉给予非离子型对比剂后，有血-脑屏障或血-脑脊液屏障破裂表现的患者，分析其临床表现和CT征象。方法：①回顾性分析8例经静脉或动脉给予非离子型对比剂(200～450ml)后，有血-脑屏障或血-脑脊液屏障破坏临床表现和CT征象的患者。②前瞻性分析30例患败血症并疑有脓肿的重症监护患者，在给予240ml非离子型对比剂后对其行胸腹部CT扫描，接着行颅部CT扫描以排除败血症性病变。结果：回顾性分析证明血-脑屏障的破坏可在有危险因素的年老患者注入大剂量对比剂后发生。前瞻性研究发现，在30例败血症患者中，3例有相同的CT征…     

液体栓塞剂的研究现状和进展

简要介绍了液体栓塞剂的定义、特性和分类,重点叙述了目前国内外常用的液体栓塞剂的作用机制及应用状况,提出了使用的注意事项,展望了液体栓塞剂的研究方向.     

MR对比剂的研究现状及其临床应用

随着ＭＲ技术的不断发展 ,ＭＲ对比剂的应用也越来越广泛。作为第一代的磁共振顺磁性对比剂 ,Ｇｄ ＤＴＰＡ有效地提高了ＭＲＩ的诊断水平。近年来 ,人们又开发出了许多新型的ＭＲ对比剂 ,如 :超顺磁性氧化铁颗粒、细胞特异性及组织器官特异性对比剂等。这些对比剂的应用为ＭＲＩ这一影像学检查手段展示了广阔的前景。笔者着重介绍ＭＲ对比剂的分类、作用机理及其临床应用。1　对比剂的分类及作用机理对比剂的分类方法有多种 ,按照作用机理可分为顺磁性阳性对比剂和磁化率阴性对比剂 ;按照生物分布特性可分为非特异性细胞外液间隙对比剂、由…     

影响DSA图像质量因素的临床应用探讨

图像是影像学诊断和治疗的依据，而数字减影血管造影技术(DSA)对疾病的诊断更离不开图像的质量。较高的DSA图像质量能给诊断提供有力的证据，通过对100例患者各部位DSA图像质量比较发现DSA图像的质量与整个检查过程中的每一个环节，每个参数以及机器的性能密切相关。     

心脏MR对比剂及其应用

目前，心脏ＭＲＩ影像学已发展成为形态兼有功能信息的诊断技术。梯度回波扫描法和回波平面成像法，结合对比剂在心脏病中的应用，具有鉴别心肌缺血、估计心肌灌注、区分阻塞性和再灌注性心肌梗塞以及识别心肌活力的能力。本对此将作一概述，并着重实验性研究进展。     

小剂量对比剂胸部CT增强检查

目的 评价小剂量对比剂在胸部CT增强检查中的可行性.方法 抽取104例胸部CT增强检查,常规剂量与小剂量法进行对比分析.结果 46例小剂量胸部CT增强效果较满意,与常规剂量无显著区别.结论 如无高压注射器,小剂量胸部增强可以作为一种常规增强方法.     

Use of superparamagnetic contrast media to suppress signal from flowing spins: Preliminary experience

The authors describe their preliminary experience with the use of superparamagnetic magnetic resonance (MR) imaging contrast media for suppression of signal from flowing blood. The goal of this work was to determine if a superparamagnetic contrast agent could successfully eliminate blood signal during cardiac-gated MR imaging, thereby eliminating or reducing flow artifacts associated with the complex and variable hemodynamics within the heart chambers. Imaging and data analysis were performed in 17 dogs subjected to experimental myocardial infarction as part of a parallel project. Six doses (0.2, 1, 2, 3.5, 4, 5, and 10 mg/kg) of AMI-25, an experimental contrast agent, were used in the study. Spin-echo imaging was performed immediately before and every 5 minutes (for an average of 25 minutes) after bolus injection of the contrast agent. Variations in the image signal-to-noise ratio relative to a baseline (before injection of contrast agent) image were assessed as a function of dose and time. Preliminary results suggest that a considerable reduction in blood flow artifacts and, hence, increases in image signal-tonoise ratio can be achieved at doses greater than or equal to 3.5 mg/kg, for approximately 20 minutes after injection. Doses equal to or less than 2 mg/kg and images obtained more than 20 minutes after injection (regardless of dose) did not reliably show hemodynamic artifact suppression.     

Dialysis and contrast media

In a previous survey we revealed uncertainty among responders about (a) whether or not to perform hemodialysis in patients with severely reduced renal function who had received contrast medium; and (b) when to perform hemodialysis in patients on regular treatment with hemodialysis or continuous ambulatory dialysis who received contrast medium. Therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and to issue guidelines. The committee performed a Medline search. Based on this, a report and guidelines were prepared. The report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy. Hemodialysis and peritoneal dialysis safely remove both iodinated and gadolinium-based contrast media. The effectiveness of hemodialysis depends on many factors including blood and dialysate flow rate, permeability of dialysis membrane, duration of hemodialysis and molecular size, protein binding, hydrophilicity, and electrical charge of the contrast medium. Generally, several hemodialysis sessions are needed to removal all contrast medium, whereas it takes 3 weeks for continuous ambulatory dialysis to remove the agent completely. There is no need to schedule the dialysis in relation to the injection of iodinated or MR contrast media or the injection of contrast agent in relation to the dialysis program. Hemodialysis does not protect poorly functioning kidneys against contrast-medium-induced nephrotoxicity. Simple guidelines are given. Electronic Publication     

Fundamental study of DSA images using gadolinium contrast agent

Most contrast agents used in digital subtraction angiography (DSA) are non-ionic iodinated contrast agents, which can cause severe side effects in patients with contraindications for iodine or allergic reactions to iodine. Therefore, DSA examinations using carbon dioxide gas or examinations done by magnetic resonance imaging (MRI) and ultrasound (US) were carried out in these patients. However, none of these examinations provided images as clear as those of DSA with an iodinated contrast agent. We experienced DSA examination using a gadolinium contrast agent in a patient contraindicated for iodine. The patient had undergone MRI examination with a gadolinium contrast agent previously without side effects. The characteristics of gadolinium and the iodinated contrast agent were compared, and the DSA images obtained clinically using these media were also evaluated. The signal-to-noise (SN) ratio of the gadolinium contrast agent was the highest at tube voltages of 70 to 80 kilovolts and improved slightly when the image intensifier (I.I.) entrance dose was greater than 300 microR (77.4 nC/kg). The dilution ratios of five iodinated contrast agents showed the same S/N value as the undiluted gadolinium contrast agent. Clinically, the images obtained showed a slight decrease in contrast but provided the data necessary to make a diagnosis and made it possible to obtain IVR without any side effects. DSA examinations using a gadolinium contrast agent have some benefit with low risk and are thought to be useful for patients contraindicated for iodine.