Abdollah Vahid, Parent Eric C, Battié Michele C
Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, 3-48 Corbett Hall, Edmonton, AB T6G 2G4, Canada.
Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, 2-50 Corbett Hall, Edmonton, AB T6G 2G4, Canada.
Biomed Tech (Berl). 2018 Jul 26;63(4):453-460. doi: 10.1515/bmt-2016-0178.
Degenerated discs have shorter T2-relaxation time and lower MR signal. The location of the signal-intensity-weighted-centroid reflects the water distribution within a region-of-interest (ROI). This study compared the reliability of the location of the signal-intensity-weighted-centroid to mean signal intensity and area measurements. L4-L5 and L5-S1 discs were measured on 43 mid-sagittal T2-weighted 3T MRI images in adults with back pain. One rater analysed images twice and another once, blinded to measurements. Discs were semi-automatically segmented into a whole disc, nucleus, anterior and posterior annulus. The coordinates of the signal-intensity-weighted-centroid for all regions demonstrated excellent intraclass-correlation-coefficients for intra- (0.99-1.00) and inter-rater reliability (0.97-1.00). The standard error of measurement for the Y-coordinates of the signal-intensity-weighted-centroid for all ROIs were 0 at both levels and 0 to 2.7 mm for X-coordinates. The mean signal intensity and area for the whole disc and nucleus presented excellent intra-rater reliability with intraclass-correlation-coefficients from 0.93 to 1.00, and 0.92 to 1.00 for inter-rater reliability. The mean signal intensity and area had lower reliability for annulus ROIs, with intra-rater intraclass-correlation-coefficient from 0.5 to 0.76 and inter-rater from 0.33 to 0.58. The location of the signal-intensity-weighted-centroid is a reliable biomarker for investigating the effects of disc interventions.
退变椎间盘的T2弛豫时间较短，磁共振信号较低。信号强度加权质心的位置反映了感兴趣区域（ROI）内的水分布。本研究比较了信号强度加权质心位置相对于平均信号强度和面积测量的可靠性。在43例有背痛的成年人的矢状位T2加权3T磁共振成像上测量L4-L5和L5-S1椎间盘。一名评估者对图像进行了两次分析，另一名评估者进行了一次分析，均对测量结果不知情。椎间盘被半自动分割为整个椎间盘、髓核、前环和后环。所有区域的信号强度加权质心坐标在评估者内（0.99-1.00）和评估者间可靠性（0.97-1.00）方面均显示出优异的组内相关系数。所有ROI的信号强度加权质心Y坐标的测量标准误差在两个水平上均为0，X坐标为0至2.7毫米。整个椎间盘和髓核的平均信号强度和面积在评估者内可靠性方面表现优异，组内相关系数为0.93至1.00，评估者间可靠性为0.92至1.00。环ROI的平均信号强度和面积的可靠性较低，评估者内组内相关系数为0.5至0.76，评估者间为0.33至0.58。信号强度加权质心的位置是研究椎间盘干预效果的可靠生物标志物。
