Department of Health Kinesiology and Applied Physiology, Concordia University, 7141 Sherbrooke Street W, SP-165.29, Montreal, QC, H4B 1R6, Canada.
Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA.
BMC Med Imaging. 2023 Mar 30;23(1):48. doi: 10.1186/s12880-023-00992-w.
The purpose of this study was to evaluate the agreement between paraspinal muscle composition measurements obtained from fat-water images using % fat-signal fraction (%FSF) in comparison to those obtained from T2-weighted magnetic resonance images (MRI) using a thresholding method.
A sample of 35 subjects (19 females, 16 males; 40.26 ± 11.3 years old) was selected from a cohort of patients with chronic low back pain (LBP). Axial T2-weighted and IDEAL (Lava-Flex, 2 echo sequence) fat and water MR images were obtained using a 3.0 Tesla GE scanner. Multifidus, erector spinae, and psoas major muscle composition measurements were acquired bilaterally at L4-L5 and L5-S1 using both imaging sequences and related measurement methods. All measurements were obtained by the same rater, with a minimum of 7 days between each method. Intra-class correlation coefficients (ICCs) were calculated to assess intra-rater reliability. Pearson Correlation and Bland-Altman 95% limits of agreement were used to assess the agreement between both measurement methods.
The intra-rater reliability was excellent for all measurements with ICCs varying between 0.851 and 0.997. Strong positive correlations indicating a strong relationship between composition measurements were obtained from fat-water and T2-weighted images for bilateral multifidus and erector spinae muscles at both spinal levels and the right psoas major muscle at L4-L5, with correlation coefficient r ranging between 0.67 and 0.92. Bland-Altman plots for bilateral multifidus and erector spinae muscles at both levels revealed excellent agreement between the two methods, however, systematic differences between both methods were evident for psoas major fat measurements.
Our findings suggest that utilizing fat-water and T2-weighted MR images are comparable for quantifying multifidus and erector spinae muscle composition but not of the psoas major. While this suggests that both methods could be used interchangeably for the multifidus and erector spinae, further evaluation is required to expand and confirm our findings to other spinal levels.
本研究旨在评估使用脂肪信号分数（%FSF）的脂肪水图像与使用阈值方法的 T2 加权磁共振图像（MRI）获得的竖脊肌组成测量值之间的一致性。
从慢性腰痛（LBP）患者队列中选择了 35 名受试者（19 名女性，16 名男性；40.26±11.3 岁）。使用 3.0T GE 扫描仪获得轴向 T2 加权和 IDEAL（Lava-Flex，2 个回波序列）脂肪和水 MR 图像。使用两种成像序列和相关测量方法，在 L4-L5 和 L5-S1 双侧获得多裂肌、竖脊肌和腰大肌的肌肉组成测量值。所有测量均由同一位评分者进行，两种方法之间至少间隔 7 天。计算组内相关系数（ICC）以评估评分者内的可靠性。使用 Pearson 相关和 Bland-Altman 95%一致性界限来评估两种测量方法之间的一致性。
所有测量的评分者内可靠性均为优秀，ICC 值在 0.851 到 0.997 之间。在两个脊柱水平的双侧多裂肌和竖脊肌以及右侧 L4-L5 的腰大肌的脂肪水和 T2 加权图像之间获得了强烈的正相关，表明两种测量方法之间存在很强的关系，相关系数 r 范围在 0.67 到 0.92 之间。双侧多裂肌和竖脊肌在两个水平的 Bland-Altman 图显示两种方法之间具有很好的一致性，但在腰大肌脂肪测量方面，两种方法之间存在系统差异。
我们的发现表明，使用脂肪水和 T2 加权 MRI 可以比较准确地量化多裂肌和竖脊肌的组成，但不能用于腰大肌。虽然这表明这两种方法可以在多裂肌和竖脊肌之间互换使用，但需要进一步评估以扩大和确认我们在其他脊柱水平的发现。
