翻转角对钆塞酸二钠增强MRI图像质量的影响  

Effect of Image Quality of Gd-EOB-DTPA Enhanced MRI by Increasing Flip Angle

作　　者：郝铸 肖煜东[1] 刘欢[1] 周顺科[1] HAO Zhu XIAO Yudong LIU Huan ZHO U Shunke(Department of Radiology, the Second Xiangya Hospital of Central South University, Changsha 410000, China)

机构地区：[1]中南大学湘雅二医院放射科,湖南长沙410000

出　　处：《中国医学影像学杂志》2016年第12期924-929,共6页Chinese Journal of Medical Imaging

摘　　要：目的肝细胞对钆塞酸二钠（Gd-EOB-DTPA）的吸收明显降低,从而减弱了肝实质与病变图像的对比,本文拟探讨通过增加翻转角以提高肝细胞期图像质量的可行性。资料与方法回顾性分析肝脏病变患者114例均行Gd-EOB-DTPA增强MRI扫描,其中非肝硬化组39例及肝硬化Child A级组36例、Child B级组23例、Child C级组16例,以T1加权脂肪抑制及三维容积内插值法屏气检查（VIBE）序列,采用翻转角9°和翻转角27°分别获得平扫期及肝细胞期5 min、10 min、15 min、20 min的图像,计算各组不同时间的2种扫描方式肝内病灶和正常肝组织区域的信噪比（SNR值）、正常肝组织区域和肝内病灶的对比（LLC值）,正常肝组织区域信号强度和肝内病灶信号强度的比值（LLSIR值）,并比较2种扫描方式不同时间SNR值、LLC值、LLSIR值的差异。结果翻转角27°扫描时LLC值、LLSIR值大于翻转角9°扫描的LLC值、LLSIR值（P〈0.05）。Child B级组、Child C级组在肝细胞期15~20 min时翻转角9°的LLC值及LLSIR值降低,而翻转角27°时LLC值及LLSIR值是趋于水平的。结论 Gd-EOB-DTPA增强MRI扫描时,重度肝硬化患者的翻转角9°比翻转角27°明显提高Child B级和Child C级患者的图像质量,对肝脏病变的诊断更加准确,为临床治疗提供依据。Purpose It has been demonstrated that hepatocytes uptake of Gd-EOB-DTPA obviously decreased, which would result in decreased liver-to-lesion contrast. Therefore, this study was to evaluate the potential of increasing flip angle to improve the image quality of Gd-EOB-DTPA enhanced MR. Materials and Methods A total of 114 patients with focal liver lesions（FLLs）, who underwent Gd-EOB-DTPA-enhanced MR of the liver, were enrolled in this retrospective study. 39 patients were noncirrhotic group, 36 patients were Child-Pugh A group, 23 patients were Child-Pugh B group, and 16 patients were ChildPugh C group. T1-weighted with fat suppression volume interpolated breath hold examination（VIBE） sequence was acquired before and 5 min, 10 min, 15 min, 20 min after the administration of Gd-EOB-DTPA with both conventional low FA（9 °） and high FA（27°） protocols separately. Signal to noise ratio（SNR）, liver to lesion contrast（LLC）, the liver to lesion SI ratio（LLSIR） were calculated and analyzed between low and high FA protocol images in each group and each scan time. Results The LLC and LLSIR on GdEOB-DTPA-enhanced MR images using a high FA（27°） protocol were significantly higher in comparison with the conventional low FA（9°）. In Child B group and Child C group, the LLC and the LLSIR with low FA significantly reduced during 15~20 min after contrast agent injection, however with high FA, the value of LLC and LLSIR tended to be horizontal. Conclusion A high FA protocol in comparison with the conventional 9° FA can obviously improve the image quality, which is reliable for liver lesion depiction on GdEOB-DTPA-enhanced MR images, especially to those with severe liver cirrhosis.

关 键 词：肝疾病 肝硬化 磁共振成像 钆塞酸二钠 图像质量 

分 类 号：R575.2[医药卫生—消化系统] R445.2[医药卫生—内科学]