磁共振钆对比剂增强前后对APT信号影响的研究  

Quantification of the impact of Gadolinium agent on amide-proton-transfer weighted MRI:An ex vivo and in vivo study

作　　者：杨倩 刘周 邹丽艳 罗虹虹 吴卫星 姬红 肖嘉辉 罗德红 YANG Qian;LIU Zhou;ZOU Liyan;LUO Honghong;WU Weixing;JI Hong;XIAO Jiahui;LUO Dehong(Department of Radiology,National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital&Shenzhen Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College,Shenzhen 518116,China;Laboratory,National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital&Shenzhen Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College,Shenzhen 518116,China;Central laboratory,National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital&Shenzhen Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College,Shenzhen 518116,China;Department of Radiology,National Cancer Center/National Clinical Research Center for Cancer,Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing 100021,China)

机构地区：[1]国家癌症中心/国家肿瘤临床医学研究中心/中国医学科学院北京协和医学院肿瘤医院深圳医院放射诊断科,深圳518116 [2]国家癌症中心/国家肿瘤临床医学研究中心/中国医学科学院北京协和医学院肿瘤医院深圳医院检验科,深圳518116 [3]国家癌症中心/国家肿瘤临床医学研究中心/中国医学科学院北京协和医学院肿瘤医院深圳医院中心实验室,深圳518116 [4]国家癌症中心/国家肿瘤临床医学研究中心/中国医学科学院北京协和医学院肿瘤医院影像诊断科,北京100021

出　　处：《磁共振成像》2022年第6期81-87,共7页Chinese Journal of Magnetic Resonance Imaging

基　　金：深圳市高水平医院建设专项经费。

摘　　要：目的通过体外模体实验和体内人体试验,探究临床剂量钆(Gd)对比剂对酰胺质子转移效应的影响。材料与方法参考临床剂量,向24个装有鸡蛋清的试管中放入不同剂量的Gd对比剂制成体模,对体模进行磁共振扫描,为了验证结果的可重复性,对体模进行三次扫描,并对扫描结果进行一致性分析。体内试验通过对19名脑肿瘤患者进行对比剂注射前后酰胺质子转移成像(amide proton transfer,APT)扫描。使用MATLAB软件计算每个试管以及大脑不同区域,包括整个脑组织、外周水肿、肿瘤区域、脑白质和脑灰质的APT值,通过余弦相似度量化对比剂增强前后APT图像的相似性,配对t检验比较对比剂增强前后APT值的差异。结果体外实验结果表明三次扫描APT值的组内相关系数为0.998,且随着MRI对比剂浓度的增加,体模中各管的平均APT值呈下降趋势。当加入的Gd剂量小于1μL时,APT值的平均值保持相对稳定,并在12%左右波动(范围为11.61%~13.42%)。但当Gd添加剂量超过1μL时,蛋清的APT值显著降低。直到添加剂量达到20μL左右,APT值的下降逐渐稳定在2%左右(范围为1.88%~2.13%)。体内试验结果显示,对于整个脑组织和脑灰质以及非强化肿瘤病灶而言,对比剂增强前后病灶APT值没有显著变化(P=0.18、0.21、0.53);对于脑白质和强化肿瘤病灶,对比剂增强前后APT值均显著升高(P<0.05)。结论体外实验和体内试验均证实,对比剂增强以后,APT信号会受到不同程度的影响,尤其是对于强化比较明显的病灶。因此在进行临床扫描方案设计时,为避免对比剂对APT信号的影响,应该在注射对比剂前进行APT扫描。Objective:To investigate the impact of Gadolinium agent(Gd)in clinical dosage on the amide proton transfer(APT)effect by a designed ex vivo phantom study and in vivo human study.Materials and Methods:A phantom was made by mixing a gradient of24 dosages of Gd-based contrast agent with 10 mL pure egg white in each tube,with reference to the clinical dosage.To verify the reproducibility of the results,the phantom was scanned three times and the scan results were analyzed for consistency.Nineteen patients with brain tumor had undergone routine clinical brain MR scan,in which APT weighted imaging was added before and after the administration of Gd.On an in-house MATLAB platform,APT values were calculated and measured for each tube of the phantom,and different regions of interest(ROIs)of the brain,including peripheral edema,tumor area,white matter(WM)and gray matter(GM).Similarity between the pre-contrast and post-contrast APT map was quantified using cosine similarity.Paired student t-test was used to evaluate the difference in the APT values between the same ROI of pre-contrast and post-contrast APT maps.Results:The results of ex vivo experiment showed that the three scans had a high consistency(ICC=0.998),and along with the increase of the MRI contrast agent concentration,the average APT value of each tube in the phantom showed a downward trend.When the added Gd content was less than1μL,the average value of APT remained relatively stable and fluctuated around 12%(from 11.61%to 13.42%).However,when the Gd content exceeded 1μL,the APT value of the egg white was considerably reduced.Until the content reached about 20μL,the decline rate of APT value gradually stabilized at about 2%(from 1.88%to 2.13%).The results of in vivo experiment showed that for the whole brain tissue,gray matter and weakly enhanced tumor lesions,the APT values not significantly changed between before and after contrast agent enhancement(P=0.18,0.21,0.53).For white matter and enhanced tumor lesions,the APT values were significantly increased bet

关 键 词：磁共振成像 化学交换饱和转移成像 酰胺质子转移成像 钆对比剂 

分 类 号：R445.2[医药卫生—影像医学与核医学]