三倍量国产钆喷替酸葡甲胺增强MRI探查脑转移瘤的研究

目的 评价３倍量（０．３ｍｍｏｌ／ｇ）国产钆喷替酸葡甲胺（Ｇｄ－ＤＴＰＡ）增强ＭＲＩ探查脑转移瘤的效果。方法 用国产Ｇｄ－ＤＴＰＡ３倍量增加ＭＲＩ检查５５例怀疑脑转移瘤的患者。对ＭＲ扫描所见进行定性,定量分析。结果 ３倍量增强比常规量增强扫描发现了理多的转移病灶,分别为３７及１７５个。对３倍量增强扫描多发现的１３８个病灶的定量分析表明,３倍量增强使病灶的相对信号强度明显增高。尤其值得指出的是,２     

钆喷替酸葡甲胺-白蛋白增强MR淋巴造影鉴别良恶性淋巴结的实验研究

目的 步探索组织间隙应用钆喷替酸葡甲胺-白蛋白（HSA-Gd-DTPA）的阳性MR淋巴造影在鉴别良、恶性淋巴结中的价值。方法 西兰兔12只，体重2．0～2．5kg。6只兔单侧后腿肌肉注射蛋黄乳胶，用于建立腘淋巴结的反应性增生模型（反应性增生组），另6只兔单侧后腿肌肉接种VX2肉瘤，用于建立胭窝淋巴结肿瘤转移模型（VX2肉瘤转移组），对侧正常胭窝淋巴结用作对照（正常组）。分析各组胭窝淋巴结在平扫及组织间隙注射0．04～0．05mmol／kgHSA-Gd-DTPA24h后的MR[特征并与病理检查对照。结果平扫时，正常组（共计6个淋巴结）、反应性增生组（共计8个淋巴结）和VX2瘤转移组（共计10个淋巴结）均表现为T1WI上等或稍高信号，T2WI上高信号。增强后24h，正常组和反应性增生组淋巴结呈明显的均匀强化，而8个转移性淋巴结分别表现为环状、云絮状和“充盈缺损”等不均匀的强化模式，2个淋巴结为完全不强化。结论 织间隙应用HSA-Gd-DTPA的阳性MR淋巴造影可准确鉴别良、恶性淋巴结。     

相对表观弥散系数与钆喷替酸葡甲胺增强MRI诊断兔头颈转移淋巴结的对比研究

目的:比较相对表观弥散系数(rADC)和钆喷替酸葡甲胺(Gd-DTPA)增强MRI诊断兔头颈部转移淋巴结的准确性。方法:24只新西兰大白兔,随机分成2组,每组12只,分别建立炎性淋巴结模型、VX2肿瘤淋巴结转移模型。Gd-DTPA增强前行T1WI、T2WI、磁共振弥散加权成像(DWI)序列扫描,注射Gd-DTPA 80s后行T1WI序列扫描。测量淋巴结、同层肌肉的ADC值,计算淋巴结/肌肉的rADC值,测量增强前、后T1WI序列淋巴结、同层肌肉的信号强度(SI)值,计算增强前后信号强度比值(SIr),并进行统计学分析。结果:经病理证实,炎症组取出淋巴结26枚,肿瘤组取出转移淋巴结14枚。炎症组、肿瘤转移组淋巴结的rADC值、SIr值差异均具有统计学意义(t值分别为-8.30,4.76,P均<0.05);利用rADC值鉴别良、恶性淋巴结ROC曲线下面积(AUC)是0.93,阈值0.88,灵敏度为92.3%,特异度为92.9%;SIr值的AUC是0.81,阈值是1.66,灵敏度为78.6%,特异度为88.5%。结论:炎症组、肿瘤转移组淋巴结的rADC值、SIr值差异具有统计学意义;rADC值比钆剂增强扫描SIr值鉴别转移性淋巴结具有较高的准确性。     

钆喷替酸葡甲胺-脂质体在兔MRI淋巴成像的应用研究

目的 研究钆喷替酸葡甲胺(Gd-DTPA)脂质体载体的淋巴组织靶向增强效果.材料与方法采用乙醇诱导法制备包裹Gd-DTPA的交错融合脂质体.将12只新西兰兔以数字表法随机分为对照组和反应性增生组,每组6只.反应性增生组采用兔大腿肌肉和腰窝皮下注射蛋黄乳胶的方法建立胭窝、腹股沟和腹膜后淋巴结三组相连续的反应性增生模型.分析各组淋巴结在Gd-DTPA脂质体增强前后的MRI特征,并采用配对t检验进行比较.结果 Gd-DTPA脂质体平均粒径2.2μm,平均包封率为82%,平均载药量为53%.平扫时两组腹膜后淋巴结大小有差异(t=164.21,P<0.01),而信号强度在T_1WI和脂肪抑制T_1WI上均无差异(P值均>0.05).Gd-DT-PA脂质体增强后,腘窝和腹股沟淋巴结在15 min时达到最大强化,SNR与平扫时相比差异有统计学意义(t值分别为76.32和48.39,P值均<0.05).腹膜后淋巴结强化较轻,约在30 min时达到最大强化,但SNR与平扫时相比差异无统计学意义(t=0.57,P>0.05).结论 Gd-DTPA可包裹于脂质体载体内,并可以用MRI显示载体淋巴组织靶向增强效果,为下一步鉴别肿瘤转移性淋巴结与反应性增生淋巴结打下了良好的基础.     

口服钆喷酸葡胺在3.0T MR胰胆管成像中的应用

目的：探讨钆喷酸葡胺作为胃肠道阴性对比剂在3.0T磁共振胰胆管成像中的应用价值.方法：对39例病人分别在口服钆喷酸葡胺前后进行磁共振胰胆管成像检查,得到两组对照图像,请放射科3位高年资医生对两组图像进行评估后行统计学分析.结果：采用χ^2检验分析,χ^2值为62,P〈0.001,两组差异具有显著性意义.结论：口服钆喷酸葡胺后行磁共振胰胆管成像,图像中胃肠道液体信号几乎完全被抑制,既经济又方便,在磁共振胰胆管成像中更应该值得推广应用.     

钆喷替酸葡甲胺-壳聚糖颗粒载体在小鼠肠壁吸附的MRI研究

目的 探讨钆喷替酸葡甲胺(Gd-DTPA)-壳聚糖颗粒(Gd-CPs)载体在小鼠直肠壁黏附和吸收情况,实现结肠黏膜途径微粒载体的MR分子成像.方法 采用乳化-微滴融合技术合成包裹Gd-DTPA的Gd-CPs和壳聚糖颗粒(CPs).将16只小鼠以数字表法随机分为Gd-CPs和CPs组,每组8只,将Gd-CPs和CPs混悬液分别注入小鼠直肠内,于灌肠前、保留灌肠中和灌肠40 min后行直肠MR扫描.测量灌肠前后直肠壁、盆壁肌肉和图像背景MR信号强度,计算灌肠前后肠壁与盆壁肌肉的相对信号值,并采用配对t检验进行比较.结果 Gd-CPs粒径约500 nm,Gd-DTPA包裹量质量分数约30%.Gd-CPs组灌肠前后直肠壁相对信号值分别为0.84±0.06和0.98±0.09(t=4.327,P＜0.01);CPs组灌肠前后直肠壁相对信号值分别为0.83±0.04和0.84±0.05(t=0.658,P＞0.05).Gd-CPs组直肠壁信号增加率中位数为19.0%.电子显微镜示Gd-CPs颗粒位于结肠黏膜细胞内.结论 Gd-DTPA可包裹于壳聚糖微粒载体内,并可以用MRI显示载体结肠壁黏附和吸收现象,MRI是活体内监测结肠黏膜途径颗粒载体运转机制的有效技术.     

静脉注射对比剂钆喷替酸葡甲胺对肾功能正常及轻、中度异常者近期血清肌酐值的影响

目的 探讨静脉注射对比剂Gd-DTPA对常规MR增强扫描人群肾功能的影响.方法 连续收集门诊住院病例623例,均注射Gd-DTPA行MR增强扫描检查的病例进行研究,检测患者增强扫描前2周内的基础血清肌酐值以及增强扫描后24～72 h内的血清肌酐值,并计算其肾小球滤过率估算值(eGFR)进行分组及统计分析.根据注射对比剂剂量将患者分为常规剂量组和双倍剂量组,各组根据注射前eGFR值再各分为肾功能正常、轻度异常及中度异常组.对各组注射前后血清肌酐值的比较均使用配对样本的t检验,eGFR均值的比较均使用成组配对样本秩和检验.结果 无患者出现严重不良反应及严重肾功能衰竭.注射对比剂后,总体血清肌酐值从(74.0±17.2)μmol/L降至(71.5±19.0)μmoL/L(t=5.39,P＜0.05);除双倍剂量下肾功能轻度组的血清肌酐值从(89.6±12.2)μmoL/L升至(92.1±14.6)μmol/L(t=0.68,P＞0.05),肾功能中度异常组从(118.3±15.3)μmol/L升至(135.7±8.5)μmol/L(t=2.02,P＜0.05)之外,肾功能正常组以及常规剂量下各组的血清肌酐值均降低.结论 Gd-DTPA在常规剂量下经静脉注射对肾功能正常及轻、中度异常者的近期血清肌酐值影响不大,是一种比较安全的MR对比剂.但对于肾功能异常者行双倍剂量注射时需密切观察并随访.     

CT扫描在X刀治疗鼠脑胶质瘤中的应用研究

目的：探讨ＣＴ检查在Ｘ刀治疗大鼠Ｃ６胶质瘤中的作用。材料和方法：ＣＴ２ｍｍ薄层扫描，Ｘ刀治疗剂量参照临床患者常用量，定为１５、２０、３０、４０Ｇｙ。经ＣＴ检查，选出适于Ｘ刀５ｍｍ准直器治疗直径的３～５ｍｍ瘤的大鼠４６只，分为治疗和对照组。结果：治疗组大鼠平均生存期４０．４ｄ，对照组２３．５ｄ，两组间有显著差异。ＣＴ复查发现Ｘ刀治疗后大鼠脑肿瘤有所缩小或消失。结论：ＣＴ检查是研究大鼠脑肿瘤的理想方法。     

钆喷替酸葡甲胺-白蛋白的合成及间隙注射后MR淋巴造影的实验研究

目的：制备Gd3＋标记的二乙三胺五乙酸-白蛋白（钆喷替酸葡甲胺-白蛋白,Gd-DTPA-HSA）,在动物实验中观察其淋巴结靶向强化效果,并探讨其潜在的应用价值。方法：①选定4个不同pH值的反应体系及不同的cDTPAa/HSA摩尔比率,测定不同反应条件下每个白蛋白分子上所结合的Gd3＋离子数量,计算不同反应条件DTPA-HSA的偶联效率;②健康新西兰兔6只,平扫后在双侧后脚掌趾蹼间隙各注射0.2ml Gd-DTPA-HSA,给药后第30min、1h、3h扫描。相关参数与平扫时相同。测量增强前后窝淋巴结的信号强度并计算其强化率。结果：①在cDTPAa/HSA摩尔比相同的条件下,每分子HSA-DTPA结合的Gd3＋数目和DTPA-HSA的偶联效率随着反应体系pH值的增高而增加;②在反应体系pH值一定的条件下,cDTPAa/HSA摩尔比为200：1的条件下每分子HSA-DTPA结合的Gd3＋数量大于二者摩尔比为100：1时所结合的Gd3＋数量,但前者的DTPA-HSA偶联效率低于后者;③经趾蹼间隙给药后,小腿淋巴管和窝淋巴结明显、均匀的强化。结论：pH=8.0的0.1M NaHCO3反应缓冲体系有利于HSA与DTPA的偶联反应。HSA-Gd-DTPA是一种有效的淋巴结特异性对比剂,能够靶向强化淋巴结。     

钆贝酸二葡甲胺与钆喷酸葡胺乳腺MRI的多中心、双盲、随机、个体间交叉对照研究(检出实验)

目的利用前瞻性、多中心双盲随机数据对0.1mmol/kg剂量的钆贝酸二葡甲胺与钆喷酸葡胺对比剂增强乳腺MRI行个体间对照研究。材料与方法研究经学院评     

肝脏MR动态增强扫描：Gd-EOB-DTPA与Gd-DTPA的个体内对照研究

目的：比较钆塞酸二钠（Gd-EOB-DTPA）及钆喷酸葡胺（Gd-DTPA）肝脏 MR动态增强扫描腹腔脏器及血管的强化特点,重点比较Gd-EOB-DTPA移行期与Gd-DTPA平衡期的图像特点。方法：本研究为前瞻性、个体内随机对照研究。25例病理证实为原发直肠癌或结肠癌、怀疑肝转移的患者,3天内行2次肝脏 MR 动态增强检查,分别使用 Gd-EOB-DTPA及Gd-DTPA两种对比剂。动态增强扫描的序列相同,包括平扫、动脉期、门静脉期、平衡期（Gd-DTPA）／移行期（Gd-EOB-DTPA）。图像客观评估中,测量各期相图像上血管及肝脾实质的信号强度。以椎旁肌肉的信号为参考,计算相对信号强度（RS）并比较两组间的差异,以及不同期相时肝实质RS的差异。主观评估：读片者主观评价增强扫描各期相图像上,主动脉、门静脉及肝静脉与肝实质的相对信号强度。结果：肝实质的RS：在动脉期Gd-DTPA 组明显高于Gd-EOB-DTPA组（t＝3．006,P＝0．005）;在门静脉期及平衡期／移行期,两组检查的差异无统计学意义（t＝1．788,P＝0．086;t＝0．781,P＝0．442）。Gd-EOB-DTPA检查时,门静脉期肝实质RS明显高于动脉期（t＝－3．014,P＝0．006）,移行期RS与门静脉期的差异无统计学意义。Gd-DTPA检查时,平衡期肝实质RS明显低于门静脉期（t＝5．827,P＝0．000）。主观评估：Gd-DTPA增强扫描平衡期图像上所有患者的主动脉、门静脉、肝静脉均为高信号（100％）;Gd-EOB-DTPA 增强扫描移行期图像上主动脉、门静脉、肝静脉均以低或等信号为主（84％,92％,92％）。结论：Gd-EOB-DTPA动态增强 MR 检查,肝脏实质在门静脉期及移行期呈持续强化,其移行期的图像特征与Gd-DTPA平衡期的图像特征有明显不同,在影像诊断时应予以关注。     

Intra-individual comparison of image contrast in SPIO-enhanced liver MRI at 1.5T and 3.0T

The purpose of the study was to examine if the higher susceptibility at 3.0 Tesla (T) compared to 1.5 T will affect the contrast in MR imaging of the liver after application of superparamagnetic iron oxide particles (SPIO). The study was approved by our institutional review board and informed consent was obtained. Seventeen healthy volunteers were examined in a prospective, intra-individual comparative study within one day on a 1.5 T and a 3.0 T MRI system. T2 weighted TSE sequences were acquired after bolus injection of a SPIO contrast agent. Image contrast and signal to noise ratio (SNR) were compared between the field strengths. Image contrast was calculated between the liver tissue and the kidneys / spleen / muscles and fluids. The students’T-test was used for statistical analysis. No influence of the higher field strength could be observed on image contrast except for the liver / muscle contrast. This was due to a distinct SNR increase of the muscle tissue at 3.0 T as a result of their relaxation properties. The higher susceptibility at 3.0 T compared to 1.5 T does not translate into a stronger signal attenuation of the SPIO enhanced liver parenchyma.     

Diagnostic value of gadopentetate dimeglumine for 1.5-T MR imaging of musculoskeletal masses: comparison with unenhanced T1- and T2-weighted imaging.

Three magnetic resonance (MR) imaging techniques (T1-weighted, T2-weighted, and T1-weighted gadopentetate dimeglumine--enhanced) were compared in 32 consecutive MR imaging studies of 26 patients with suspected musculoskeletal masses. T2-weighted images were superior to T1-weighted enhanced images with respect to detection and definition of lesions in 12% of cases (n = 4) and were equal in 88% of cases (n = 28). T2-weighted images were also superior to T1-weighted images in 38% of cases (n = 12). In no cases were T1-weighted enhanced images superior to T2-weighted images. In two cases, T1-weighted images were superior to both T1-weighted enhanced and T2-weighted images. The authors conclude that gadopentetate dimeglumine did not provide much value in lesion detection above that obtained with T2-weighted images. They also conclude that T1-weighted images were occasionally superior to T1-weighted enhanced images and T2-weighted images because of loss of definition between fat and lesion on the latter.     

Comparison of gadopentetate dimeglumine and albumin-(Gd-DTPA)30 for microvessel characterization in an intracranial glioma model

To compare the performance of macromolecular albumin gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA)₃₀ and low molecular weight gadopentetate dimeglumine for microvessel characterization, we examined an intracranial 9L glioma model in which increased angiogenesis, hypervascularity, and hyperpermeability mimic characteristics of clinical malignant brain tumors. Dynamic MRI data were analyzed using a bidirectional, two-compartment kinetic model to extract quantitative estimates for fractional blood volume (fBV) and permeability surface area product (PS). Three criteria were used for comparison of contrast agent performance: (a) tumor conspicuity, defined as the contrast-to-noise ratio (CNR); (b) dynamic range of differential permeability estimates between tumor and normal brain; (c) reasonableness of blood volume estimates. Gadopentetate was superior to macromolecular albumin-(Gd-DTPA)₃₀ for detection of 9L brain gliomas and for measurements of hyperpermeability.     

大鼠正常肝脏Mn-DPDP增强磁共振研究

目的 :探讨大鼠正常肝脏磁共振表现与Mn DPDP注射剂量、扫描延迟时间和扫描序列的关系。方法 :将 2 0只健康SD雄性大鼠随机分为 3组 ,每组经尾静脉注射Mn DPDP ,剂量分别为 5、10和 2 5 μmol/kg ,对肝脏进行FMPSPGR和SET1WI序列扫描。扫描延迟时间为 5、15、3 0、60、12 0、180和 2 40min。MRI检查后取肝脏大体标本HE染色进行病理学对照观察。结果 :大鼠肝脏信号随Mn DPDP注射剂量增加而升高 ,但两者并不存在线性相关。 2 5 μmol/kg组增强后各时间点肝脏信号净增加百分率比 5 μmol/kg和 10 μmol/kg组明显 ,且具有显著性差异 (P <0 .0 5 ) ,后二者之间无显著性差异 (P >0 .0 5 )。同一注射剂量组FMPSPGR序列肝脏信号绝对值在相同时间点上较SET1WI序列高 ,两序列肝脏净信号增加百分率无显著性差异 (P >0 .0 5 )。结论 :大鼠正常肝脏MRI检查选择梯度回波序列 (FMPSPGR序列 )和SET1WI序列在Mn DPDP( 2 5 μmol/kg)注射后 60min内可以获得较佳图像。     

Efficacy and safety of gadopentetate dimeglumine in the evaluation of patients with a suspected tumor of the extracranial head and neck

The clinical efficacy and safety of gadopentetate dimeglumine as a paramagnetic contrast agent for magnetic resonance (MR) imaging of the extracranial head and neck was evaluated in a multicenter trial involving 60 patients. Patients with signs and/or symptoms of a tumor in the nasopharynx, oropharynx, hypopharynx, larynx, or neck were studied. T1-weighted images were obtained before and after injection of gadopentetate dimeglumine, 0.1 mmol/kg, at a rate of 10 mL/min. No lesions were seen on the pre- or postinjection images of five of the 60 patients. Postinjection lesion enhancement was present in 53 of the remaining 55 (96%) patients. The absence of postinjection lesion enhancement in one of the two remaining patients was useful information. Postinjection impressions differed from preinjection diagnosis in 22 of 60 (37%) patients. Additional information was obtained from postinjection relative to preinjection images in 38 of 60 (63%) patients. Four adverse experiences were reported in three of 60 (5%) patients. Two mild (chest wall pain and headache) and one moderate (nausea) adverse experiences were considered by the authors to be unrelated to the studied drug. One severe adverse experience was reported. This patient had a seizure, considered by the investigator to be remotely related to the study drug and attributed to the abrupt withdrawal of anticonvulsant medications. The data indicate that gadopentetate dimeglumine is safe and efficacious in the evaluation of patients with extracranial head and neck lesions.     

Evaluation of gadobutrol,a macrocyclic,nonionic gadolinium chelate in a brain glioma model: Comparison with gadoterate meglumine and gadopentetate dimeglumine at 1.5 T,combined with an assessment of field strength dependence,specifically 1.5 versus 3 T

Purpose:

To evaluate in a rat brain glioma model intraindividual tumor enhancement at 1.5 T using gadobutrol (Gadovist), a nonionic, macrocyclic chelate currently in clinical trials in the United States, in comparison with both an ionic macrocyclic chelate, gadoterate meglumine (Dotarem), and an ionic linear chelate, gadopentetate dimeglumine (Magnevist), and to compare the degree of tumor enhancement with gadobutrol at 1.5 and 3 T.

Materials and Methods:

A total of 24 rats, divided into three groups with n = 8 animals per group, were evaluated. Animals in group 1 received injections of gadobutrol and gadopentetate dimeglumine, whereas those in group 2 received gadobutrol and gadoterate meglumine. Injections were performed in random order and separated by 24 hours. Magnetic resonance imaging (MRI) examinations were performed immediately following each contrast injection with a 1.5 T MR system. Animals in group 3 received gadobutrol injections using the same protocol but with scans performed at 1.5 and 3 T. In all examinations, T1‐weighted images were acquired precontrast, 1 minute postcontrast, and at 4 consecutive 2‐minute intervals thereafter. A contrast dose of 0.1 mmol/kg was used in all instances.

Results:

In groups 1 and 2, tumor signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) were higher for gadobutrol compared to both other agents at each timepoint postcontrast injection. The improvement in tumor CNR with gadobutrol, depending on time, was between 12% and 40% versus gadopentetate dimeglumine, with the difference achieving statistical significance at 7 minutes. The improvement in tumor CNR with gadobutrol, depending on time, was between 15% and 27% versus gadoterate meglumine, with the difference statistically significant at 5 and 9 minutes. In group 3 the improvement in tumor SNR and CNR seen with the increase in field strength from 1.5 to 3 T for gadobutrol was statistically significant at all acquired timepoints (P < 0.002). CNR mean values ranged from 10.4 ± 2.9 to 24.6 ± 5.0 at 1.5 T and from 20.5 ± 5.9 to 47.8 ± 15.7 at 3 T depending on the timepoint postcontrast.

Conclusion:

Consistently greater tumor enhancement was noted at all measured timepoints following contrast injection with gadobutrol compared to both gadopentetate dimeglumine and gadoterate meglumine at 1.5 T. A substantial further improvement in tumor enhancement was noted using gadobutrol at 3 T. J. Magn. Reson. Imaging 2010;31:549–555. © 2010 Wiley‐Liss, Inc.     

Theoretical analysis of gadopentetate dimeglumine enhancement in T1-weighted imaging of the brain: Comparison of two-dimensional spin-echo and three-dimensional gradient-echo sequences

By using a theoretical model, the signal difference-to noise ratios between simulated lesions and normal white matter and gray matter were calculated as a function of lesion concentration of gadopentetate dimeglumine (GD) for two-dimensional (2D) T1-weighted spin-echo (SE), three-dimensional (3D) steady-state spoiled gradient-echo (GRE) (FLASH [fast low-angle shot]), and 3D magnetization-prepared rapid gradient echo (MP-RAGE) pulse sequences. The 3D GRE sequences provided greater contrast enhancement at relatively high [GD], and the 2D SE sequence demonstrated greater enhancement and a higher rate of enhancement at low [GD]. The results predict that at low [GD], certain lesions could probably be detected with the 2D SE sequence but possibly not with one or both of the 3D GRE sequences. At high [GD], certain lesions could probably be detected with one or both of the 3D GRE sequences but possibly not with the 2D SE sequence. This provides a potential explanation for the clinical observation that certain contrast agent enhanced lesions appear less conspicuous on 3D GRE images than on 2D SE images and vice versa. Modified parameter values were derived for the 3D FLASH and 3D MP-RAGE sequences that are predicted to produce contrast enhancement behavior equivalent or superior to that of a conventional 2D SE sequence.