Spine Lab, Department of Orthopedic Surgery, School of Medicine, The First Affiliated Hospital, Zhejiang University, 79# Qingchun Road, Hangzhou, China.
Department of Orthopedic Surgery, Jinyun People's Hospital, Lishui, China.
Eur Spine J. 2021 Sep;30(9):2577-2585. doi: 10.1007/s00586-021-06811-6. Epub 2021 Mar 19.
Although signal intensity on T2W axial images is sensitive in detection of fatty infiltration to assess paraspinal muscle degeneration, it is affected by inhomogeneities of magnetic fields and individual variabilities. The purpose of this study was to propose reference adjusted signal measures on T2W axial images and determine their capacities in reflecting age-related lumbar paraspinal muscle degeneration.
Lumbar MR images of 421 population-based subjects (177 men and 244 women, mean age 53.1 years, range 19.8-87.9 years) were studied. A custom software Spine Explore (Tulong 2.0) was used to automatically obtain paraspinal measurements of multifidus, erector spinae and psoas major. FCSA/TCSA was defined as functional cross-sectional area relative to total cross-sectional area of paraspinal muscle. Two new signal measures were canal-adjusted and cerebrospinal fluid (CSF)-adjusted signal, defined as the ratio between mean signal measurements and the mean signal of the canal and CSF.
The raw signal measurements of the paraspinal muscles were weakly correlated to age (r = 0.28-0.39, P < 0.001). When the signal of canal (r = 0.43-0.59, P < 0.001) or CSF (r = 0.45-0.61, P < 0.001) was used as reference, the correlations substantially increased. Signal measurements of three paraspinal muscles, adjusted or not, were strongly associated with Goutallier score (ρ = 0.60-0.65, P < 0.001) and FCSA/TCSA (r = -0.64 to -0.82, P < 0.001). Greater Goutallier score was associated with greater age (r = 0.38-0.60, P < 0.001), while Lumbar indentation value (LIV) not.
On routine T2W axial MR images the adjusted signal measurements using an internal reference of CSF or canal can better reflect age-related degenerative changes in the paraspinal muscles.
尽管 T2W 轴位图像上的信号强度在检测脂肪浸润以评估脊柱旁肌肉退变方面很敏感，但它受磁场不均匀性和个体变异性的影响。本研究旨在提出 T2W 轴位图像上的参考调整信号测量方法，并确定其反映与年龄相关的腰椎脊柱旁肌肉退变的能力。
研究了 421 名基于人群的受试者（177 名男性和 244 名女性，平均年龄 53.1 岁，范围 19.8-87.9 岁）的腰椎 MRI。使用定制软件 Spine Explore（Tulong 2.0）自动获得多裂肌、竖脊肌和腰大肌的脊柱旁测量值。FCSA/TCSA 定义为脊柱旁肌肉的功能横截面积与总横截面积的比值。提出了两种新的信号测量方法，即管腔调整信号和脑脊液（CSF）调整信号，定义为平均信号测量值与管腔和 CSF 平均信号的比值。
脊柱旁肌肉的原始信号测量值与年龄呈弱相关（r=0.28-0.39，P<0.001）。当使用管腔（r=0.43-0.59，P<0.001）或 CSF（r=0.45-0.61，P<0.001）作为参考时，相关性显著增加。三种脊柱旁肌肉的信号测量值，无论是否调整，均与 Goutallier 评分（ρ=0.60-0.65，P<0.001）和 FCSA/TCSA（r=-0.64 至-0.82，P<0.001）高度相关。更大的 Goutallier 评分与更大的年龄相关（r=0.38-0.60，P<0.001），而腰椎凹陷值（LIV）则不然。
在常规 T2W 轴位 MR 图像上，使用 CSF 或管腔内部参考的调整信号测量值可以更好地反映与年龄相关的脊柱旁肌肉退行性变化。
