肝脏局灶性病变磁共振弥散加权成像中三种呼吸采集方式的比较  

Comparison of three diffusion-weighted MRI techniques for focal hepatic lesions

作　　者：史卓[1] 赵心明[1] 宋俊峰[1] 马霄虹[1] 叶枫[1] 

机构地区：[1]北京协和医学院中国医学科学院肿瘤医院影像诊断科,北京100021

出　　处：《中国肿瘤临床与康复》2014年第2期139-143,共5页Chinese Journal of Clinical Oncology and Rehabilitation

摘　　要：目的比较3T磁共振弥散加权成像（diffusionweightedimaging，DWI）中屏气、呼吸触发、自由呼吸等3种采集技术对肝脏初诊局灶性病变的评估效能。方法56例患者在GE公司3．0TMR磁共振机进行常规MR和3种DWI检查，其中DWI的弥散感度（b值）均为800s／mm^2，扫描层数均为24，范围包括全肝。屏气方式的激励次数为1，呼吸触发为2，自由呼吸为4，其余参数保持一致。各序列最终扫描时间屏气为20s，呼吸触发2min，自由呼吸1min。最后由影像科2名高年资主治医师盲法记录、评价测得的数据。结果3种DWI采集方式对所有肝脏局灶性病变的检出率（92．0％～95．5％）和准确率（86．8％～89．3％）差异无统计学意义（P〉0．05），3组测得的正常肝脏和病变量化表观弥散系数（ADC）值具有较好的相关性（同类相关系数ICC分别为0．732和0．951），但屏气状态下测得的信噪比和对比度噪声比低于呼吸门控和自由呼吸状态（P〈0．05）。结论3种DWI采集方式对于肝脏局灶性病变的检出率和准确率差异无统计学意义（P〉0．05），但非屏气序列可提供更高的信噪比和对比度噪声比，其中自由呼吸技术更具时间效率。Objective To compare the breathhold, respiratory-triggered, and free-breathing tech- niques in diffusion-weighted magnetic resonance imaging（MRI） for the evaluation of focal liver lesions on a 3. OT system. Methods Fifty-six patients with focal liver lesions underwent original MR sequence and three diffusion-weighted imaging（DWI） of the liver on a 3.0 Tesla（T） system. All sequences were per- formed with b value of 800 and identical parameters except for signal averages （ one for breathhold, two for respiratory-triggered, and four for free-breathing）. The total scan time of each DWI sequences were as fol- lows： 20s for breathhold, 2min for respiratory-triggered, and lmin for free-breathing. Finally, two visiting staffs of the imaging department evaluated the measured data separately. Results For lesion detection sen- sitivity（92. 0-95.5% ） and characterization accuracy （86. 8 -89. 3% ）, there were no significant differ- ences among the three DWI（P 〉0. 05）. The ADC values of the liver and focal lesions measured using the three DWI techniques showed good correlation （ ICC were 0. 732 and 0. 951 ）. The SNRs and CNRs of the liver and lesions were significantly lower for breathhold DWI than for non-breathhold DWI （ P 〈 0. 05 ）. Conclusions For lesion detection and characterization, there were no significant differences between breathhold and non-breathhold DWI, but the non-breathhold DWI could provide higher SNR and CNR, es- pecially the free-breathing technique was more time efficient.

关 键 词：肝脏 弥散加权成像 采集方式 图像评价 

分 类 号：R445.2[医药卫生—影像医学与核医学]