腹部MRI口服Gd—DTPA的实验研究

目的：在体外和实验动物身上研究不同扫描参数条件下，不同浓度Ｇｄ－ＤＴＰＡ的表现特点，为进一步的临床研究做准备，材料与方法，东芝公司０．３５Ｔ超导ＭＲＩ系统，常规Ｔ１ＷＩ，ＰＤＷＩ和Ｔ２ＷＩ扫描，第一军医大学药物所提供的胃肠道用Ｇｄ－ＤＴＰＡ，结果：Ｇｄ－ＤＴＰＡ的增强效果是与浓度相关的；结论，动物实验表明，作为胃镜道地比剂，浓度１．０～２．０ｍｍｏｌ／ＬＧｄ－ＤＴＰＡ的效果优于０．５ｍｍｏｌ／Ｌ，     

Gd—DTPA增中磁共振成像在诊断肝细胞肝癌中的价值

目的：评价Ｇｄ－ＤＴＰＡ增强磁共振成像在诊断肝细胞肝癌中的价值。资料与方法：经手术病理或临床证实的肝细胞肝癌５３例行磁共振检查，成像序列为：自旋回波Ｔ１ＷＩ，脂肪抑制ＰＤ、Ｔ２ＷＩ及Ｇｄ－ＤＴＰＡ增强Ｔ１ＴＩ（Ｔ１ＷＩ＋Ｃ）。总结各序列图像对瘤体、子灶、假包膜、肿瘤镶嵌样结构、门静脉瘤栓等结构显示率。结果：Ｔ１ＷＩ、Ｔ２ＷＩ、Ｔ１ＷＩ＋Ｃ对瘤体的显示率分别为６６％、１００％、６６％，显示的子灶数分     

Gd—DTPA在诊断卵巢肿块中的作用及评价

目的：正确评价Ｇｄ－ＤＴＰＡ在诊断卵巢病变中的作用材料和方法，采用ＭＲ的Ｔ２加权成像（Ｔ２ＷＩ）和增强前后Ｔ１加权成像（Ｔ１ＷＩ）３种序列，对具有手术病理结果的７５例１１０个卵巢肿块进行回顾性分析，结果：静注Ｇｄ－ＤＴＰＡ后以及下变化特征；（１）恶性肿瘤特征显示正确率由８３．３％升至１００．０％。（２）良、恶性肿块的实质均有明显强化，其强化率之间无显著性差异（Ｐ〉０．０５），不同强化时程，绝大多数     

Gd—DTPAMRI在心绞痛中的作用

目的：探讨Ｇｄ－ＤＴＰＡ增强ＭＲＩ在心绞痛中的作用。材料和方法：２２例心绞痛作Ｇｄ－ＤＴＰＡ增强前后ＭＲＩ检查,其中１６例作冠状动脉造影检查,１１例作ＳＰＥＣＴ检查。结果：增强ＭＲＩ上,１８例（８２％）可见局部异常强化信号,其部位与临床ＥＣＧ吻合,与ＣＡ、ＳＰＥＣＴ所示心肌缺血部位一致。在ＭＲＩ上的异常强化信号与冠状动脉狭窄、ＳＰＥＣＴ显示灌注缺损密切有关。结论：Ｇｄ－ＤＴＰＡＭＲＩ为心绞痛的诊断提供有价值的依据。     

急性、亚急性、慢性心肌梗塞在Gd－DTPA增强MRI上的信号表现

通过对Ｇｄ－ＤＴＰＡ增强前后ＭＲＩ上急性、亚急性和慢性心肌梗塞区的心肌信号变化规律的总结，期望对心肌梗塞作出定性定量的诊断。材料和方法：３２例不同时期心肌梗塞及１２例正常心脏做了Ｇｄ－ＤＴＰＡ增强前后ＭＲＩ扫描，增强后为动态观察。结果：１０例急性心肌梗塞和１０例亚急性心肌梗塞均见到心肌的异常强化信号：１２例慢性心肌梗塞中仅４例（３３％）见到异常强化信号。正常心肌为均匀一致的轻度信号增强。不同时期的心肌梗塞异常信号范围不同，信号率的动态变化规律也不同。结论：Ｇｄ－ＤＴＰＡ增强ＭＲＩ及动态观察可以显示心肌梗塞的部位、范围及为心肌梗塞的分期提供依据。     

肿瘤样脑炎的MRI表现和Gd－DTPA增强的诊断价值

目的：研究肿瘤样脑炎的ＭＲＩ表现和Ｇｄ－ＤＴＰＡ增强的诊断价值。材料和方法：报告９例肿瘤样脑炎的ＭＲＩ所见，并与１８例脑星形细胞瘤的增强磁共振成像（ＣＥＭＲＩ）表现进行对比分析。结果：肿瘤样脑炎的非增强磁共振成像（ＮＣＭＲＩ）表现为长Ｔ１、长Ｔ２信号，缺乏特征性，其ＣＥＭＲＩ表现为（１）斑片状高信号，大小不一，强弱不一，散在分布。（２）单个或多个结节状增强，（３）脑膜线状增强。（４）血管壁套状增强。脑星形细胞瘤的典型ＭＲＩ表现为结节状增强或为伴有中心坏死的不规则花环状增强。结论：ＣＥＭＲＩ能反映肿瘤样脑炎的炎性渗出、肉芽肿形成、硬膜充血和血管周围炎的病理特点，对肿瘤样脑炎和脑星形细胞瘤的鉴别诊断有重要意义。     

静脉注射Gd—DTPA对比剂在磁共振检查中的应用及护理

目的：总结用静脉注射Gd—DTPA对比剂进行磁共振增强检查的护理体会。方法：应用静脉快速弹丸注射方法，对其检查前的心理护理，禁忌症的掌握，注射的剂量、速度、扫描时间的选择与不良反应的处理。以及注射后的病情观察作详细的记录，统计、分析。结果：231例注射Gd—DTPA对比剂病人中，高度强化141例，中度强化40例。阳性181例，阳性率约占78％，无强化病例50例，约占22％。结论：用静脉注射Gd—DTPA对比剂进行磁共振增强检查，科学的护理是保障MRI图像质量及受检者安全的关键因素。     

腹部磁共振成像应用口服造影剂枸橼酸铁铵的研究

缺乏一种理想的口服造影剂已成为腹部ＭＲＩ发展中的一大障碍。笔者选用枸橼酸铁铵（ＦＡＣ）作为ＭＲ口服造影剂，对其作用机理、增强规律、最佳浓度、造影方法、临床效果等问题进行了试管、动物实验和临床对照研究。ＦＡＣ具有较强的弛豫增强作用，低浓度时，以缩短Ｔ＿１为主，信号强度随浓度升高而增高；高浓度时，以缩短Ｔ＿２为主，信号强度随浓度升高而降低。当ＦＡＣ浓度为２．１ｍｍｏｌ／Ｌ时，Ｔ＿１Ｗ和Ｔ＿２Ｗ像均得到满意的对比增强，故为最佳浓度。ＦＡＣ口服造影可以标记胃肠道、提高邻近正常结构和病灶的解剖分辨率。造影时配合应用胃肠道松弛剂效果更好，低张造影组肝左叶、胰腺各段及胆总管下端的分辨效果明显优于平扫组。ＦＡＣ具有价格低廉、无毒副作用、造影效果良好等优点，是较理想的ＭＲ口服造影剂。     

Gd－DTPA增强MRI对肺癌的分期价值

利用平扫和Ｇｄ－ＤＴＰＡ（二乙二胺五醋酸钆·马根维显）增强ＭＲＩ图像对３８例原发性支气管肺癌的ＴＮＭ分期进行了分析，并与ＣＴ和病理分期结果进行了对照。重点评估了Ｔ因素分期的四项指标：（１）侵犯胸膜；（２）侵入纵隔；（３）与周围肺组织继发性改变（阻塞性肺炎和肺不张）的鉴别；（４）胸内淋巴结转移。结果显示：对侵犯胸膜的显示，ＭＲＩ与ＣＴ相似，其敏感性分别为４０％和７５％，特异性为８６％和９３％，准确性为７４％和８９％；对侵犯纵隔的显示，ＭＲＩ比ＣＴ敏感，特异性和准确性相似。     

Pharmacokinetic Analysis of Gd-DTPA Enhancement in dynamic three-dimensional MRI of breast lesions

The purpose of this study was to demonstrate that dynamic MRI covering both breasts can provide sensitivity for tumor detection as well as specificity and sensitivity for differentiation of tumor malignancy. Three-dimensional gradient echo scans were used covering both breasts. Before Gd-DTPA bolus injection, two scans were obtained with different flip angles, and after injection, a dynamic series followed. Thirty-two patients were scanned according to this protocol. From these scans, in addition to enhancement, the value of T1 before injection was obtained. This was used to estimate the concentration of Gd-DTPA as well as the pharmacokinetic parameters governing its time course. Signal enhancement in three-dimensional dynamic scanning was shown to be a sensitive basis for detection of tumors. In our series, all but two mam-mographically suspicious lesions did enhance, and in three cases, additional enhancing lesions were found, two of which were in the contralateral breast. The parameter most suited for classification of breast lesions into benign or malignant was shown to be the pharmacokinetically defined permeability k₃₁, which, for that test, gave a sensitivity of 92% and a specificity of 70%. Our three-dimensional dynamic MRI data are sensitive for detection of mammographically occult breast tumors and specific for classification of these as benign or malignant.     

动态增强MRI在肺癌诊断中的应用

目的：探讨动态增强ＭＲＩ在肺癌诊断中的作用。材料和方法：前瞻性动态增强ＭＲＩ研究１２例原发支气管肺癌，６例良性肺内结节并与手术、病理对照；测量不同病变区（肿瘤、继发炎变、结核球、炎性假瘤和淋巴结）在静脉团注造影剂后不同时间的信号强度。结果：绝大多数肺癌在团注造影剂后明显强化，３～１０ｍｉｎ达到高峰，随后信号逐渐下降，而多数结核球主体无明显强化，动态曲线平坦。肺癌周围继发炎变增强程度高于瘤体，可将两者区分。炎性假瘤增强显著但边缘模糊，可见较长索条影。结论：动态增强ＭＲＩ能提供更多的信息，对肺癌的诊断、鉴别诊断和分期等均有帮助。     

MRI MnDPDP增强对原发性肝细胞癌的诊断价值

目的 :评估MRIMnDPDP增强不同延迟时间成像对原发性肝细胞癌的诊断价值。材料和方法 :对 3 6例HCCs行MRIMnDPDP增强研究。静脉滴注MnDPDP结束后 5min开始每隔 5min成像 1次 ,直至 40min ;第二天行延迟 2 4h成像。成像序列为SET1WI和FMPSPGRT1WI。对不同延迟时间图像的信噪比 (S/N)、对比度噪声比 (C/N)及病灶显示率进行比较研究。结果 :(1)不同延迟时间图像的S/N无统计学差异。 (2 ) 5～ 2 5min图像肝与HCC之间C/N高于 3 0min以后图像 (P<0 0 5 )。 (3 )病灶显示率和定性率均以延迟 2 4h最高 (92 7% ) ,但各组图像之间无显著差异。结论 :MnDPDP增强MRI的HCC显示率和定性率均以延迟 2 4h图像为佳     

Magnetic resonance imaging of human cerebral infarction: Enhancement with Gd-DTPA

Summary Five patients (1 female and 4 males) with cerebral infarction of 4 h to 27 months duration were studied 9 times with magnetic resonance (MR) using Gd-DTPA. Spin-echo (SE) MR images (MRI) were obtained before and after the administration of Gd-DTPA, and correlative CT scans were performed on the same day. In 2 cases, 4 h and 27 months after the ictus, there was no enhancement with Gd-DTPA. There was faint enhancement in 2 cases with cerebral infarction of about 24h duration and obvious enhancement in all cases in the subacute stage. Compared with enhanced CT, MR using Gd-DTPA demonstrated more obvious enhancement of infarcted areas. MR enhancement using Gd-DTPA showed a gradual increase and the accumulated Gd-DTPA in infarcted areas slowly diffused to the periphery. MR enhancement with Gd-DTPA is similar to that of enhanced CT, but may be more sensitive in the detection of blood brain barrier breakdown.     

核磁弥散成像及增强扫描在诊断非缺血性颅脑病变中的意义

目的探讨核磁弥散成像及增强扫描在诊断非缺血性颅脑病变中的意义。方法收集经临床证实的非缺血性颅脑病变56例,均作常规MRI T2WI、T1WI、增强扫描及DWI,分析其DWI信号及增强表现。结果32例颅脑肿瘤、11例感染性病变、9例血肿、4例多发性硬化病例,病变在DWI上呈高或稍高信号。结论常规MRI T2WI、T1WI扫描图像,弥散成像及增强扫描在非缺血性颅脑病变的定性诊断中具有重要意义。     

Gd—DTPA增强MRI诊断心肌梗塞

15例心脏作Gd-DTPA增强前后MRI检查,增强后为连续动态观察。其中7例为正常对照;7例为心肌梗塞(包括5例亚急性和2例慢性心肌梗塞);1例为陈旧性心肌梗塞。结果显示:增强前正常心肌信号率与梗塞心肌信号率无差别。增强后梗塞心肌信号率既高于增强前也明显高于其周围的正常心肌。无论肉眼观察还是信号测量均发现Gd-DTPA增强MRI能诊断心肌梗塞,改善心肌梗塞的显示。作者对增强后心肌信号率的系列变化作了描述。     

肿瘤廓清率在动态增强MRI检查中对肾上腺肿瘤的鉴别诊断价值

目的　探讨应用动态增强MRI检查技术 ,以肿瘤的廓清率为标准 ,再结合该时间点的信号增加比 ,对肾上腺腺瘤与非腺瘤进行鉴别诊断的临床价值。方法　 3 6例共 41个肾上腺肿瘤均先行常规SE序列T1 WI及T2 WI成像 ,再利用屏气快速多层面破坏性梯度回波序列 (fastmultiplanarspoiledgradient-echo ,FMPSPGR)行轴位扫描 ,先平扫 ,再以同样条件行MRI动态增强检查 ,观察病变的增强程度并分别测量肿瘤实质部分的信号值。分别比较腺瘤与非腺瘤的廓清率及信号增加比 ,明确其鉴别诊断价值。结果　延时 5min并以廓清率 2 2 %为阈值时 ,诊断腺瘤的敏感性 74% ,特异性 73 % ,准确性 73 % ;若将延时 5min时肿瘤的廓清率 (2 2 % )与信号增加比(<0 .48)相结合 ,则诊断腺瘤的敏感性、特异性、准确性明显提高 ,分别为 95 %、91%、93 %。结论　利用动态增强检查技术 ,以肿瘤的廓清率为标准 ,再结合该时间点的信号增加比 ,可在最短的时间内提高肾上腺腺瘤与非腺瘤的鉴别诊断水平     

Contrast agent influences MRI phase‐contrast flow measurements in small vessels

Contrast‐enhanced MR angiography is often combined with phase contrast (PC) flow measurement to answer a particular clinical question. The contrast agent that is administered during contrast‐enhanced MR angiography may still be present in the blood during the consecutive PC flow measurement. The aim of this work was to evaluate the influence of contrast agent on PC flow measurements in small vessels. For that purpose, both in vivo measurements and computer simulations were performed. The dependence of the PC flow quantification on the signal amplitude difference between blood and stationary background tissue for various vessel sizes was characterized. Results show that the partial‐volume effect strongly affects the accuracy of the PC flow quantification when the imaged vessel is small compared to the spatial resolution. A higher blood‐to‐background‐contrast level during imaging significantly increases the partial‐volume effect and thereby reduces the accuracy of the flow quantification. On the other hand, a higher blood‐to‐background‐contrast level facilitated the segmentation of the vessel for flow rate determination. PC flow measurements should therefore be performed after contrast agent administration in large vessels, but before contrast agent administration in small vessels. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.