新型超声造影剂和成像方法在肝脏疾病中的应用

常规超声显像,包括彩色多普勒超声、彩色能量图观察到的是一种相对静态的血流动力学状态.在造影超声应用以前,超声诊断技术缺乏有效的动态造影以增强信息是一种明显的不足,故在诊断肝脏肿瘤等多种肝脏疾病的准确性方面,被认为略逊于经常使用造影增强的CT、MRI等影像技术.近年来,随着超声造影剂研制的不断改进以及超声成像技术的发展,新型声学造影方法成功地开辟了全新的超声造影领域.大量研究证明[1-10],声学造影能有效地增强肝脏的二维超声影像,反映正常组织和病变组织不同的血流灌注、造影剂分布和影像动态变化,在肝脏占位性病变的诊断和鉴别诊断方面的优越性越来越为人们所共识.     

超声造影在肝脏疾病中的应用进展

随着一代代新型超声对比剂的相继问世和造影成像技术的不断发展 ,超声造影成像已成为超声医学界关注的热点 ,其在肝脏疾病诊断、鉴别诊断与肝肿瘤非手术治疗疗效监测中的应用不但广泛 ,而且具有独到的优点和重要的临床价值。本文综合文献资料 ,对超声对比剂与成像技术加以概括 ,并将超声造影在肝脏疾病中的临床应用现状与进展进行综述。     

灰阶超声造影在肝脏病变中的应用

本文通过对灰阶超声造影技术原理、扫查方法的描述，介绍了一种超声造影技术的新方法。同时。通过对国内外研究者各项研究结果的综述，展现了灰阶超声造影技术在正常肝脏和肝硬化定量研究、肝脏肿瘤检出、肝内局灶性病变鉴别诊断的最新研究结果以及在这些领域中此项技术与其它检查方法对比的优缺点。表明了灰阶超声造影技术在肝脏病变的诊断中是一项实用性强、易于推广的新技术。这一技术的应用，有望达到CT及磁共振造影增强检查的效果，不久的将来在我国必将得到逐步完善和发展。     

实时超声造影成像在肝脏局灶性病变中的应用研究

超声是筛检肝肿瘤应用最广泛的影像手段,但常规的B超和彩色多普勒超声对肝脏局灶性病变的定性诊断的敏感性及特异性较低,但超声造影技术的突破性进展使肝脏超声诊断的准确率有了很大的提高,近年来,实时超声造影在肝脏疾病诊断中得到较广泛的应用,显著提高了肝脏局灶性病变的检测、定性和局部消融监测的诊断效能。     

彩色多普勒超声诊断在肝脏血管瘤治疗中的应用分析

目的分析彩色多普勒超声诊断应用于肝脏血管瘤治疗的效果。方法选取我院2006年10月-2012年10月期间因肝脏血管瘤复发的98例老年住院患者，采用彩色多普勒超声诊断仪对造影前后肝肿瘤的彩色血流表现情况、肝脏血管肿瘤的Vmax及RI进行比较。结果患者的肝肿瘤的彩色血流表现情况（I-II级和III级及以上）以及Vmax及RI在造影后显著高于造影前，比较差异显著（P〈0．01）。结论彩色多普勒超声在肝脏血管瘤的诊断上有一些局限性，但其有无创伤和易重复检查的方便快捷的优点，该方法仍应该作为肝脏血管肿瘤患者在临床上的首选检查方法，值得在临床上推广及应用。     

三维超声造影技术在肝脏的临床应用和研究进展

三维超声造影(3D- CEUS)是在已经较成熟的三维成像和二维超声造影的基础上发展起来的一项技术,在临床应用中具有其独特的优势,可用于评估肝脏和肝脏肿瘤的血供、内部结构和边界等.目前,国内外关于此技术的研究尚属于探索阶段.本文就三维超声造影的临床应用及研究进展作一系统综述.     

超声造影引导经皮穿刺活检在肿瘤诊断中的应用

尽管二维超声引导经皮穿刺活检在肿瘤诊断中具有很大优势,但是由于受到肿瘤形态、大小及内部结构等限制,可导致穿刺失败或者假阴性率增加.超声造影作为一种新的诊断技术,能够引导对肿瘤病灶的穿刺活检,提高诊断准确率.对超声造影引导经皮穿刺活检技术及其在不同部位肿瘤(肝脏肿瘤、肺部肿瘤及前列腺癌等)诊断中的应用价值予以综述.     

超声造影对肾脏小占位的诊断分析

目的:探讨不同病理类型肾脏肿瘤的造影特点,评价超声造影诊断肾脏良恶性肿瘤的应用价值,为临床诊断提供依据。方法:应用声学造影剂声诺维对27例超声诊断为肾脏占位病变或可疑肾脏占位病变的患者进行超声造影检查,分析其造影增强图像特点。结果:27例患者均满意获得清晰的肿瘤动态造影灌注图像,大部分与其正常肾组织回声等强,10例肾恶性肿瘤的造影显像比其正常肾组织快,3例肾良性肿瘤造影显像为"同进慢出";4例肾柱肥大造影后与正常肾组织造影剂显像一致;2例肾囊肿内无造影剂显示。结论:超声造影成像技术能清晰显示肾肿瘤的血流灌注特点,对肾脏肿瘤的诊断具有一定实用价值。     

超声造影对肝脏良恶性占位性病变的鉴别诊断

实时超声造影技术自应用于临床以来，其价值成为近年来研究的热点。我们对本组25例肝脏占位性病变患者进行的实时灰阶超声造影检查分析，旨在探讨超声造影对肝脏良恶性占位性病变的诊断及鉴别诊断，报道如下。     

超声造影对肝脏局灶性病变的定量分析及临床价值研究

目的探讨超声造影对肝脏局灶性病变的定量分析结果及临床价值。方法选取2017年1月~2019年1月100例肝脏病变患者,根据病变性质分为恶性组(n=67)和良性组(n=33)。分别进行实时超声造影及彩色多普勒超声检查。应用时间-强度曲线(TIC曲线)分析超声造影图像。结合TIC曲线形态及由TIC曲线得到的病灶的始增时间、达峰时间、峰值强度、峰值减半时间,分析良恶性病灶造影灌注特点。分析肝癌病灶超声造影类型与彩色多普勒超声血流分级的肿瘤大小关系。结果恶性组TIC的始增时间、达峰时间、峰值减半时间均明显早于良性组,峰值强度明显强于良性组,差异均有统计学意义(P<0.01)。随着血流分级的升高,超声造影类型的环绕型、网络型比率有降低趋势,混合型、树枝型的比率有升高趋势。血流分级与超声造影类型间存在明显相关性(χ²=21.647,P=0.010)。肿瘤≤3 cm的病灶超声造影类型以环绕型和网络型为主。肿瘤> 3 cm的病灶超声造影类型以混合型和树枝型为主。肿瘤大小与超声造影类型有明显相关性(Z=-3.768,P=0.000)。肿瘤分化程度与超声造影类型间存在明显相关性(χ²=35.950,P=0.000)。结论实时超声造影能显示肝脏局灶性病变内部血流灌注情况、判断肿瘤大小及分化程度,根据造影增强方式和TIC曲线参数能够有效鉴别肝脏良恶性病灶。     

冠状动脉三维重建在冠心病的应用价值

目的:探讨多层螺旋CT(MSCT)在冠状动脉血管造影检查中最佳的扫描技术。方法:应用回顾性心电门控技术,使用3种不同的检查技术,对62例患者进行多层螺旋CT冠状动脉增强检查:15例使用对比剂注入后延时扫描无维持注射的方法;23例使用对比剂自动跟踪技术(surestart)自动控制扫描,对比剂一次性团注的方法;24例使用surestart技术手动控制扫描、CT实时监视技术,对比剂团注后 维持注射的方法。结果:15例使用对比剂注入后延时扫描无维持注射的方法进行的冠状动脉检查,9例成功占60%(9/15);23例使用surestart技术自动控制扫描,不使用维持量注射的方法进行冠状动脉检查,16例成功,占69.57%(16/23);24例使用surestart技术手动控制扫描、CT实时监视技术,对比剂团注后 维持注射的方法,进行冠状动脉检查,22例成功,占91.67%(22/24)。结论:Surestart技术手动控制扫描、CT实时监视技术,对比剂团注后 维持注射的方法,成功率较高。     

Brain: gadolinium-enhanced fast fluid-attenuated inversion-recovery MR imaging

PURPOSE: To determine the clinical utility of gadolinium-enhanced fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) imaging of the brain by comparing results with those at gadolinium-enhanced T1-weighted MR imaging with magnetization transfer (MT) saturation. MATERIALS AND METHODS: In 105 consecutive patients referred for gadolinium-enhanced brain imaging, FLAIR and T1-weighted MR imaging with MT saturation were performed before and after administration of gadopentetate dimeglumine (0.1 mmol per kilogram of body weight). Pre- and postcontrast images were evaluated to determine the presence of abnormal contrast enhancement and whether enhancement was more conspicuous with the FLAIR or T1-weighted sequences. RESULTS: Thirty-nine studies showed intracranial contrast enhancement. Postcontrast T1-weighted images with MT saturation showed superior enhancement in 14 studies, whereas postcontrast fast FLAIR images showed superior enhancement in 15 studies. Four cases demonstrated approximately equal contrast enhancement with both sequences. Six cases showed some areas of enhancement better with T1-weighted imaging with MT saturation and other areas better with postcontrast fast FLAIR imaging. Superficial enhancement was typically better seen with postcontrast fast FLAIR imaging. CONCLUSION: Fast FLAIR images have noticeable T1 contrast making gadolinium-induced enhancement visible. Gadolinium enhancement in lesions that are hyperintense on precontrast FLAIR images, such as intraparenchymal tumors, may be better seen on T1-weighted images than on postcontrast fast FLAIR images. However, postcontrast fast FLAIR images may be useful for detecting superficial abnormalities, such as meningeal disease, because they do not demonstrate contrast enhancement of vessels with slow flow as do T1-weighted images.     

脉络膜血管瘤的MRI表现及动态增强研究

目的 探讨眼脉络膜血管瘤的常规及动态增强MRI表现.方法 回顾性分析30例(31只眼共32个病灶)经临床、眼底相及荧光血管造影确诊的脉络膜血管瘤的MRI资料,其中行平扫和常规增强扫描30例,行动态增强扫描26例,观察各个序列MRI表现,计算动态增强曲线参数.结果 32个脉络膜血管瘤病灶中,位于视乳头颞侧26个病灶,呈梭形28个病灶;与玻璃体信号相比,T1WI呈等信号23个病灶,T2研呈等信号31个病灶;增强后明显强化32个病灶,强化均匀31个病灶,不均匀1个病灶,伴视网膜脱离18只眼;动态增强扫描出现填充征12个病灶,时间-信号曲线呈速升缓降型28个病灶,峰值时问为(91.00±25.27)s,上升斜率为3.03±1.13,流出率中位数为17.06%,强化率为2.87±0.79.结论 脉络膜血管瘤MRI现病灶形态、信号及动态增强具有一定特点,能为临床诊断和治疗方案制定提供重要信息.     

An experimental model to study contrast enhancement in MR imaging of the intervertebral disk

MR imaging after IV gadolinium-DTPA administration has demonstrated contrast enhancement in traumatized lumbar intervertebral disks. To characterize the morbid anatomy that correlates with the contrast enhancement, we developed a canine model of traumatized intervertebral disks. Diskectomy was performed with a nucleotome and the spines were imaged biweekly with MR and Gd-DTPA. The spines were studied at necropsy, and their anatomic abnormalities correlated with contrast enhancement detected by MR imaging. Our preliminary results indicate that contrast enhancement occurs where granulation tissue develops in traumatized intervertebral disks.     

Importance of Contrast-Enhanced Fluid-Attenuated Inversion Recovery Magnetic Resonance Imaging in Various Intracranial Pathologic Conditions

Intracranial lesions may show contrast enhancement through various mechanisms that are closely associated with the disease process. The preferred magnetic resonance sequence in contrast imaging is T1-weighted imaging (T1WI) at most institutions. However, lesion enhancement is occasionally inconspicuous on T1WI. Although fluid-attenuated inversion recovery (FLAIR) sequences are commonly considered as T2-weighted imaging with dark cerebrospinal fluid, they also show mild T1-weighted contrast, which is responsible for the contrast enhancement. For several years, FLAIR imaging has been successfully incorporated as a routine sequence at our institution for contrast-enhanced (CE) brain imaging in detecting various intracranial diseases. In this pictorial essay, we describe and illustrate the diagnostic importance of CE-FLAIR imaging in various intracranial pathologic conditions.     

周围型胆管细胞癌临床病理与CT及MR诊断研究

目的:对比研究肝内周围型胆管细胞癌的临床病理与CT及MRI表现。方法:回顾性分析经病理学证实的周围型胆管细胞癌39例,32例行CT平扫和动态增强扫描,11例行MRI扫描,其中4例同时做过CT和MRI检查。结果:肿瘤在CT、MRI上表现为类圆形软组织肿块(肿块型)、不规则形片状异常密度(信号)影(浸润生长型)和扩张胆管腔内结节样(或菜花样)软组织肿块,动态增强扫描早期呈轻度强化,以边缘为主,延迟后扫描病灶可无明显强化,或内部呈现片状、分隔状甚至均匀性强化。病理学上见肿瘤细胞呈高柱状、立方形或扁平形排列成腺管状,中间含有增生的纤维结缔组织,在不同类型肿瘤中两者含量和分布特点不同构成不同影像表现的病理学基础。结论:周围型胆管细胞癌的临床表现缺乏特异性,动态增强扫描是CT、MRI诊断和鉴别诊断要点,排列成腺管状的瘤细胞造成肿瘤早期强化,而增生的纤维结缔组织是形成肿瘤延迟强化的病理基础。     

Use of high concentration contrast media (HCCM): principles and rationale--body CT

Numerous complex pharmacokinetic interrelationships affect the use of contrast media for computed tomography (CT) imaging. The volume, concentration, and rate of injection, all affect the degree of enhancement that is achieved with an injection of contrast material. In addition, the injection technique, whether the contrast is infused with a constant injection rate (uniphasic injection) or whether the rate is altered during the injection (multiphasic injection) also affect the magnitude and duration of contrast enhancement. In body CT imaging, the liver poses unique challenges in managing the use of intravenous contrast material because of its dual blood supply and the need to complete imaging before equilibrium occurs between the intravascular and extravascular compartments. The magnitude of hepatic enhancement that is ultimately achieved is related primarily to the amount of iodinated contrast material that accumulates in the extravascular space within the target organ, independent of the speed of the CT scanner. The key determinant of the onset of the equilibrium phase is the injection duration. Given that a high injection flow rate (4-5 ml/s) is desirable for arterial phase imaging, the injection duration is maintained with use of an appropriate contrast volume. Thus, modifications of total iodine dose are best done with alterations in contrast concentration. The magnitude of arterial enhancement that is achieved is related to both the concentration and rate of contrast administration. The speed of the scanner determines its ability to record image data during the most advantageous time period, the peak of arterial enhancement. Thus, rapid imaging is particularly advantageous for optimal contrast use in CT angiography as well as in multiphasic imaging of the parenchymal organs.     

MR imaging of the breast for the detection, diagnosis, and staging of breast cancer.

With the introduction of contrast agents, advances in surface coil technology, and development of new imaging protocols, contrast agent-enhanced magnetic resonance (MR) imaging has emerged as a promising modality for detection, diagnosis, and staging of breast cancer. The reported sensitivity of MR imaging for the visualization of invasive cancer has approached 100%. There are many examples in the literature of MR imaging--demonstrated mammographically, sonographically, and clinically occult breast cancer. Often, breast cancer detected on MR images has resulted in a change in patient care. Despite these results, there are many unresolved issues, including no defined standard technique for contrast-enhanced breast MR imaging, no standard interpretation criteria for evaluating such studies, no consensus on what constitutes clinically important enhancement, and no clearly defined clinical indications for the use of MR imaging. Furthermore, this technology remains costly, and issues of cost-effectiveness and cost competition from percutaneous biopsy have yet to be fully addressed. These factors along with the lack of commercially available MR imaging--guided localization and biopsy systems have slowed the transfer of this imaging technology from research centers to clinical breast imaging practices. Technical requirements, potential clinical applications, and potential pitfalls and limitations of contrast-enhanced MR imaging as a method to help detect, diagnose, and stage breast cancer will be described.     

Diffusionsgewichtete Magnetresonanztomographie in der Diagnostik der Encephalitis disseminata

Magnetic resonance (MR) imaging is one of the best methods in diagnosis of multiple sclerosis, particularly in disclosure of active demyelinating lesions. Aim of this study was to compare diffusion weighted imaging and contrast enhancement in the detection of active lesions. A MR study with a contrast enhanced T1-weighted pulse sequence with magnetization transfer presaturation and a diffusion weighted echoplanar pulse sequence (b = 1000 s/mm2) was performed in 17 patients (11 women, 6 men) with multiple sclerosis. 29 of 239 lesions showed an increased signal intensity in diffusion weighted imaging, 24 lesions a contrast enhancement, but only 16 lesions were visible in both pulse sequences. In patients with short clinical symptomatology significant more lesions could be detected with diffusion-weighted pulse sequence in comparison to patients with long standing symptomatology showing more lesions with contrast enhancement. Hence it is likely, that both pulse sequences detect different histopathologic changes. The early detection of demyelinating lesions in diffusion weighted imaging is attributed to the extracellular edema, however the contrast enhancement is caused by a blood brain barrier abnormality. It can be expected that diffusion weighted imaging will have a high impact on imaging of multiple sclerosis not only in therapeutic trials, but also in clinical routine.     

Multi-slice CT contrast enhancement regimens

Historically, the development of progressively faster Computed Tomography (CT) technology has dictated a recurrent need to re-examine intravenous contrast agent enhancement regimens. The most recently introduced development, the very fast, multi-slice helical/spiral systems, have raised the same issue yet again. It is possible, exploiting the technology to its maximum potential as regards speed, to perform an examination many times faster (depending on the number of detector rings from 4 to 64) even than with earlier single slice spiral instruments. In order to optimise image quality, such maximal speed gains will not usually be sought but, nevertheless, imaging time will generally be substantially reduced. It is natural that the question of a possible need to modify contrast agent enhancement protocols designed for an earlier generation of slower machines should again be considered. Using as a basis known contrast agent pharmacokinetics and results of modelling techniques, the matter is tackled in this paper.