回波平面成像校正序列改善颈髓扩散加权成像和扩散张量成像图像质量的价值  

Application of echo-planar imaging correction in diffusion weighted imaging and diffusion tensor imaging of cervical spinal cord

作　　者：刘娜 林良杰 张浩南 苗延巍[1] 刘爱连[1] 宋清伟[1] Liu Na;Lin Liangjie;Zhang Haonan;Miao Yanwei;Liu Ailian;Song Qingwei(Department of Radiology,the First Affiliated Hospital of Dalian Medical University,Dalian 116011,China;Clinical and Technical Support,Philips Healthcare,Shanghai 200233,China)

机构地区：[1]大连医科大学附属第一医院放射科,大连116011 [2]飞利浦(中国)投资有限公司临床与技术支持,上海200233

出　　处：《中华放射学杂志》2023年第6期679-683,共5页Chinese Journal of Radiology

摘　　要：目的探索回波平面成像校正(EPIC)序列对颈髓扩散加权成像(DWI)及扩散张量成像(DTI)图像质量的改善价值。方法2022年1月至3月招募志愿者33名,采用3.0 T MR行矢状面T1WI,校正前后DWI、DTI序列扫描。两名观察者在T1WI与校正前后DWI、DTI序列融合图像上勾画ROI测量表观扩散系数(ADC)值、各向异性分数(FA)值,测量偏移距离,并对图像质量进行5分法主观评分。采用组内相关系数(ICC)、Kappa检验对两名观察者测量数据和主观评分的一致性进行评价。采用配对样本t检验和Wilcoxon秩和检验比较校正前后图像定量值的差异,采用Mann-Whitney U检验比较校正前后图像主观评分的差异。结果两名观察者测量数据和主观评分一致性良好(ICC为0.912~0.999,Kappa为0.778~0.816)。校正前后DWI序列所测C6 ADC值,C4、C5、C6脊髓的偏移距离和主观评分差异均有统计学意义(P<0.05);校正前后DTI序列C1、C3脊髓的FA值,C1、C3脊髓的ADC值,C4、C5、C6脊髓的偏移距离和主观评分差异均有统计学意义(P<0.001)。结论EPIC序列可以显著降低图像畸变,改善图像质量。Objective To explore the value of echo-planar imaging correction(EPIC)for improving image quality of diffusion weighted imaging(DWI)and diffusion tensor imaging(DTI)of cervical cord.Methods A total of 33 subjects(20 males,13 females)were scanned on a 3.0 T MR scanner from January to March 2022,and the sequences included T1WI,DWI and DTI(with and without corrections).Two observers delineated the regions of interest(ROIs)on the fused images of DWI and DTI with T1WI before and after correction,and measured the average diffusion coefficient(ADC),fractional anisotropy(FA),and offset distance of ROIs between images with and without corrections.The subjective scores of image quality were also evaluated.The ICC or Kappa was used to test the consistency of the quantitative measurement and subjective scores by the two observers.The average values by the two observers would be used for subsequent analysis.The independent pair t-test and Wilcoxon test were used for comparison of objective measurements and Mann-Whitney U test was used for subjective image assessments between images with and without corrections.Results The measurement data and the subjective scores of the two observers were in good agreement(ICC 0.912-0.999,Kappa 0.778-0.816).The independent sample t-test showed the subjective scores were significantly different for the DWI and DTI images between before and after geometry and/or ADC corrections.The ADC values of C6,the offset distances measured by DWI before and after correction of C4,C5,and C6 and subjective scores were significantly different(P<0.05);The FA values of C1 and C3,ADC values of C1 and C3,offset distance of C4,C5 and C6 measured by DTI before and after correction and subjective scores were statistically significant(P<0.001).Conclusion EPI geometry correction and ADC value correction can significantly reduce geometric distortion,increase image quality,and thus improve the diagnosis accuracy of essential diseases.

关 键 词：磁共振成像 图像质量 回波平面成像校正 扩散加权成像 扩散张量成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]