乳腺组织MR扩散加权成像中GRAPPA技术的应用  

Diffusion-weighted MRI of the Breast with GRAPPA:Initial Experience

作　　者：唐建华[1] 严福华[1] 周梅玲[1] 叶芳[1] 徐鹏举[1] 沈继章[1] 陈财忠[1] 李轫晨[1] 张澍杰[1] 陈锦[1] 曾蒙苏[1] 

机构地区：[1]复旦大学附属中山医院放射科,上海200032

出　　处：《放射学实践》2010年第2期164-168,共5页Radiologic Practice

摘　　要：目的:评价在乳腺磁共振扩散加权成像(DWI)中应用全自动校准部分并行采集(GRAPPA)技术对改善图像质量及乳腺组织表观扩散系数(ADC)值测量的影响。方法:分别对28例女性乳腺MR受检者进行平面回波(EPI)序列的常规DWI和GRAPPA-DWI检查。常规DWI检查时扩散梯度因子(b)值取800s/mm2,GRAPPA-DWI检查时b值分别取800、1000s/mm2。比较不同参数条件下的图像质量分级、信噪比(SNR)及乳腺组织ADC值,并进行统计学分析。结果:在相同b值(b=800s/mm2)条件下,GRAPPA-DWI组图像质量明显优于常规DWI组,乳腺组织的SNR高于常规DWI组,两组差异均有显著性意义(P<0.01),乳腺的平均ADC值略低于常规DWI组,但两组差异无显著性意义(P>0.05)。在GRAPPA-DWI组中,b值为800s/mm2组图像质量略优于b值为1000s/mm2组,但二者差异无显著性意义(P>0.05),而b值为800s/mm2组乳腺组织的SNR高于b值为1000s/mm2组,两组差异有显著性意义(P<0.01),b值为800s/mm2时乳腺组织的ADC值略高于b值为1000s/mm2时,差异有显著性意义(P<0.05)。结论:GRAPPA技术的应用有助于改善乳腺DWI的图像质量,提高信噪比,并且不会影响乳腺组织ADC值的测量。Objective：To evaluate prospectively the improvement of the image quality with the use of generalized autocalibrating partially parallel acquisitions （GRAPPA） in diffusion-weighted imaging （DWI） of the breast and its effect on apparent diffusion coefficient （ADC） measurements. Methods：Twenty-eight women underwent echo-planar （EPI）-DWI of the breast with conventional phase encoding and with GRAPPA,respectively. The b value of 800s/mm2 was used in conventional DWI group, while two b values of 800 and 1000s/mm2 were used in GRAPPA-DWI groups. Image quality, signal-to-noise ratio （SNR） and ADC values of breast were compared with different series at the same b value of 800s/mm2 and with different b values of 800 and 1000s/mm2 in GRAPPA DWI groups. Matched-pairs Wileoxon signed rank test was used for statistical analysis. Results： Higher image quality score and SNR value of the breast were obtained in GRAPPA-DWI group than those in conventional DWI group with the same b value of 800s/mm2 and the differences were statistically significant （P〈0.01）. The mean ADC of breast in GRAPPA-DWI group was lower than that in conventional DWI group with the same b value of 800s/mm2,but there was no significant difference between the two sequences for breast ADC measurement （P〉0.05）. In GRAPPA-DWI groups, the image quality score at b value of 800s/mm2 was slightly higher than that at b value of 1000s/mm2 and there was no significant difference between them （P〉0.05）. The SNR value and the mean ADC of breast at b value of 800s/mm2 were higher than those at b value of 1000s/mm2 in GRAPPA-DWI groups and the differences were statistically significant （P〈0.05）. Conclusion： GRAPPA is useful in improving image quality and SNR of EPI- DWI of breast without compromising ADC measurements.

关 键 词：磁共振成像 扩散 并行采集技术 乳腺 

分 类 号：R445.2[医药卫生—影像医学与核医学] R655.8[医药卫生—诊断学]