Look-Locker和B1修正变量翻转角技术在正常乳腺组织T_1值测量中的对照研究
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摘要
目的:比较分析Look-Locker和B1修正变量翻转角(B1-corrected VFA)成像技术获得的正常乳腺腺体及胸壁肌肉的T1弛豫时间。方法:对77例正常乳房分别行Look-Locker和B1-corrected VFA序列扫描获得T1-mapping图像,由两位医师分别测量乳房腺体、胸壁肌肉的T1值,采用组内相关系数(ICC)对两位医师的测量结果进行一致性分析,并分析两种成像方法的变异度,比较两种成像方法的组织T1值差异。结果:两位医师之间乳腺腺体、胸壁肌肉的look-locker法获得T1值的ICC值分别为0.883、0.818;两位医师之间乳腺腺体、胸壁肌肉B1-corrected VFA法获得T1值的ICC值分别为0.796、0.757,一致性均为非常好。Look-Locker法与B1-corrected VFA法所得两种组织的T1值差异均有统计学意义[腺体组织T1值分别为(1423.42±80.63)和(2042.09±150.18)ms,t=35.14,P<0.05;肌肉组织T1值分别为(1369.79±65.24)和(2044.84±133.07)ms,t=48.53,P<0.05]。腺体组织Look-Locker法和B1-corrected VFA法获得的T1值的变异度分别为0.057和0.074,胸壁肌肉组织两种方法获得的T1值的变异度分别为0.048和0.065。结论:采用Look-Locker和B1-corrected VFA法获取正常乳房结构的T1值可行,可重复性较好;两种方法测量的T1值差异有统计学意义,但各组织的变异度较小,能反映正常乳房腺体、肌肉组织的特性,有可能为临床的进一步研究提供基础。
Objective:Comparison of the T_1 relaxation time in breast and chest wall muscles acquired by look-locker and B1 corrected variable-flip-angle technique.Methods:Look-locker and B1 corrected sequences were applied on 77 cases with normal breasts,T_1-mapping images were obtained.T_1 relaxation time of mammary gland and chest wall muscle were measured by 2radiologists independently.Interclass correlation coefficient(ICC)was used to analyze the consistency of the results measured.The coefficient of variation(CV)of T_1 relaxation time in gland and muscle was analyzed and the difference of T_1 value obtained by these 2sequences was also compared.Results:The ICC of T_1 value of mammary gland and chest wall muscle obtained by Look-locker measured by the 2radiologists was0.883 and 0.818 respectively,which obtained by B1-corrected VFA was 0.796 and 0.757 respectively,with excellent consistency.Significant differences were found in T_1 relax time between two techniques[T_1value of gland:(1423.42±80.63)vs(2042.09±150.18)ms,P<0.05,t=35.14;T_1value of muscle:(1369.79±65.24)vs(2044.84±133.07)ms,P<0.05,t=48.53].CV of T_1 relaxation time obtained by Look-Locker and B1-corrected VFA was 0.057,0.074 respectively in gland and 0.048,0.065 respectively in muscle.Conclusion:Using Look-Locker and B1-corrected VFA sequence to obtain T_1 values of normal breast structures are feasible and have good repeatability.Significant statistic difference was existed in T_1 values obtained by two methods,yet there were low degree variation between different tissues,which can reflect the characteristics of normal mammary glands and muscle tissue,and may provide guidance for further clinical study.
Objective:Comparison of the T_1 relaxation time in breast and chest wall muscles acquired by look-locker and B1 corrected variable-flip-angle technique.Methods:Look-locker and B1 corrected sequences were applied on 77 cases with normal breasts,T_1-mapping images were obtained.T_1 relaxation time of mammary gland and chest wall muscle were measured by 2radiologists independently.Interclass correlation coefficient(ICC)was used to analyze the consistency of the results measured.The coefficient of variation(CV)of T_1 relaxation time in gland and muscle was analyzed and the difference of T_1 value obtained by these 2sequences was also compared.Results:The ICC of T_1 value of mammary gland and chest wall muscle obtained by Look-locker measured by the 2radiologists was0.883 and 0.818 respectively,which obtained by B1-corrected VFA was 0.796 and 0.757 respectively,with excellent consistency.Significant differences were found in T_1 relax time between two techniques[T_1value of gland:(1423.42±80.63)vs(2042.09±150.18)ms,P<0.05,t=35.14;T_1value of muscle:(1369.79±65.24)vs(2044.84±133.07)ms,P<0.05,t=48.53].CV of T_1 relaxation time obtained by Look-Locker and B1-corrected VFA was 0.057,0.074 respectively in gland and 0.048,0.065 respectively in muscle.Conclusion:Using Look-Locker and B1-corrected VFA sequence to obtain T_1 values of normal breast structures are feasible and have good repeatability.Significant statistic difference was existed in T_1 values obtained by two methods,yet there were low degree variation between different tissues,which can reflect the characteristics of normal mammary glands and muscle tissue,and may provide guidance for further clinical study.
引文
[1] Salerno M,Kramer CM.Advances in parametric mapping with CMR imaging[J].JACC Cardiovasc Imaging,2013,6(7):806-822.
[2] Hueper K,Peperhove M,Rong S,et al.T1-mapping for assessment of ischemia-induced acute kidney injury and prediction of chronic kidney disease in mice[J].Eur Radiol,2014,24(9):2252-2260.
[3] Cassinotto C,Feldis M,Vergniol J,et al.MR relaxometry in chronic liver diseases:comparison of T1-mapping,T2-mapping,and diffusion-weighted imaging for ssessing cirrhosis diagnosis and severity[J].Eur J Radiol,2015,84(8):1459-1465.
[4] Yoon JH,Lee JM,Paek M,et al.Quantitative assessment of hepatic function:modified look-locker inversion recovery(MOLLI)sequence for T1-mapping on Gd-EOB-DTPA-enhanced liver MR imaging[J].Eur Radiol,2016,26(6):1775-1782.
[5] Li Z,Sun J,Hu X,et al.Assessment of liver fibrosis by variable flip angle T1-mapping at 3.0T[J].J Magn Reson Imaging,2016,43(3):698-703.
[6] Ding Y,Rao SX,Zhu T,et al.Liver fibrosis staging using T1-mapping on gadoxetic acid-enhanced MRI compared with DW imaging[J].Clin Radiol,2015,70(10):1096-1103.
[7]胡富碧,唐芳,车梦娇,等.正常青年人肾脏磁共振T1-mapping成像的定量研究[J].成都医学院学报,2015,10(6):661-664.
[8] Bydder GM,Steiner RE,Young IR,et al.Clinical NMR imaging of the brain:140cases[J].Am J Roentgenol,1982,139(2):215-236.
[9] Deichmann R,Haase A.Quantification of T1values by snapshotFLASH NMR imaging[J].J Magn Reson,1992,96(3):608-612.
[10] Shin W,Gu H,Yang Y.Fast high-resolution T1-mapping using inversion-recovery Look-Locker echo-planar imaging at steady state:optimization for accuracy and reliability[J].Magn Reson Med,2009,61(4):899-906.
[11] Fram EK,Herfkens RJ,Johnson GA,et al.Rapid calculation of T1using variable flip angle gradient refocused imaging[J].Magn Reson Imaging,1987,5(3):201-208.
[12]闫铄,李晶晶,谢汝明.艾滋病合并弓形虫脑病MRI表现及其预后预测价值[J].新发传染病电子杂志,2016,1(1):27-30.
[13] Ding Y,Rao SX,Chen C,et al.Assessing liver function in patients with HBV-related HCC:a comparison of T1-mapping on Gd-EOB-DTPA-enhanced MR imaging with DWI[J].Eur Radiol,2015,25(5):1392-1398.
[2] Hueper K,Peperhove M,Rong S,et al.T1-mapping for assessment of ischemia-induced acute kidney injury and prediction of chronic kidney disease in mice[J].Eur Radiol,2014,24(9):2252-2260.
[3] Cassinotto C,Feldis M,Vergniol J,et al.MR relaxometry in chronic liver diseases:comparison of T1-mapping,T2-mapping,and diffusion-weighted imaging for ssessing cirrhosis diagnosis and severity[J].Eur J Radiol,2015,84(8):1459-1465.
[4] Yoon JH,Lee JM,Paek M,et al.Quantitative assessment of hepatic function:modified look-locker inversion recovery(MOLLI)sequence for T1-mapping on Gd-EOB-DTPA-enhanced liver MR imaging[J].Eur Radiol,2016,26(6):1775-1782.
[5] Li Z,Sun J,Hu X,et al.Assessment of liver fibrosis by variable flip angle T1-mapping at 3.0T[J].J Magn Reson Imaging,2016,43(3):698-703.
[6] Ding Y,Rao SX,Zhu T,et al.Liver fibrosis staging using T1-mapping on gadoxetic acid-enhanced MRI compared with DW imaging[J].Clin Radiol,2015,70(10):1096-1103.
[7]胡富碧,唐芳,车梦娇,等.正常青年人肾脏磁共振T1-mapping成像的定量研究[J].成都医学院学报,2015,10(6):661-664.
[8] Bydder GM,Steiner RE,Young IR,et al.Clinical NMR imaging of the brain:140cases[J].Am J Roentgenol,1982,139(2):215-236.
[9] Deichmann R,Haase A.Quantification of T1values by snapshotFLASH NMR imaging[J].J Magn Reson,1992,96(3):608-612.
[10] Shin W,Gu H,Yang Y.Fast high-resolution T1-mapping using inversion-recovery Look-Locker echo-planar imaging at steady state:optimization for accuracy and reliability[J].Magn Reson Med,2009,61(4):899-906.
[11] Fram EK,Herfkens RJ,Johnson GA,et al.Rapid calculation of T1using variable flip angle gradient refocused imaging[J].Magn Reson Imaging,1987,5(3):201-208.
[12]闫铄,李晶晶,谢汝明.艾滋病合并弓形虫脑病MRI表现及其预后预测价值[J].新发传染病电子杂志,2016,1(1):27-30.
[13] Ding Y,Rao SX,Chen C,et al.Assessing liver function in patients with HBV-related HCC:a comparison of T1-mapping on Gd-EOB-DTPA-enhanced MR imaging with DWI[J].Eur Radiol,2015,25(5):1392-1398.