Zoabli Gnahoua, Mathieu Pierre A, Aubin Carl-Eric
Institute of Biomedical Engineering, Department of Physiology, Pav. Paul G. Desmarais, 2960 Chemin de la tour, Montreal, Quebec H3T 1J4 Canada.
Spine J. 2007 May-Jun;7(3):338-44. doi: 10.1016/j.spinee.2006.04.001. Epub 2006 Oct 13.
Many studies have been devoted to the role of back muscle activity in the development of scoliosis. While an imbalance in the electromyographic (EMG) activity has often been detected at the skin surface, very little information is available on the mechanisms by which such an imbalance could take place. To gain insight into those mechanisms, an important step could be the collection of anatomical data on the volume of the erector spinae muscle on both sides of the spine as well as on the skin and subcutaneous fat (skinfold) thickness separating those muscles from the body surface. For this purpose, the use of magnetic resonance (MR) imaging is appropriate.
To collect anatomical information on the erector spinae muscles and skinfold thickness along the spinal deviations of scoliotic patients.
In an observational retrospective study, MR images of scoliotic patients treated in a pediatric hospital in the last 5 years were analyzed.
Images were obtained from adolescent idiopathic scoliosis patients.
For 15 patients (Group I), three clinical acquisition protocols were used. Five investigators were asked to grade the contrast of the images obtained with each protocol. All the assessments were carried on the same monitor without any change in its settings. For the MR sequence providing the best contrast, 25 fully imaged scoliotic deviations were obtained from 17 patients (Group II). A manual segmentation with an image processing software package was done on the erector spinae muscle on both sides of the spine on each of the available images in order to determine their volume. Skinfold was also measured; first at regular intervals from C7 to L3 over the erector spinae muscle and then at sites centered over the apex of each curve.
For Group I, the spin echo (SE-T1) was found to provide the best contrast to identify the contour of individual muscle. With this sequence, the analysis of the fully imaged scoliotic curves (Group II) revealed that back muscle volume was found larger 14 times on the concave side and 11 times on the convex one. When the length of each curve was normalized and then divided into three equal regions, muscle volume was larger 11 times at the apex (6 times on concave side), 7 times above and 7 times below (4 times on the concave side for both positions). From C7 to L3, the mean skinfold thickness of each patient ranged from 7.3 mm to 16.3 mm. On average, this thickness was <10 mm between T3 and T12 but became larger at L3 level. At the apex of each scoliotic deviation, skinfold thickness was always larger on the concave side, and the difference decreased progressively as the distance from the apex increased.
A larger back muscle volume in adolescent idiopathic scoliosis patients was slightly more frequent on the concave than on the convex side. The differences were more frequent at the apex of the curve. Skinfold thickness was always greater on the concave side at the apex region.
许多研究致力于探讨背部肌肉活动在脊柱侧弯发展中的作用。虽然在皮肤表面常检测到肌电图（EMG）活动不平衡，但关于这种不平衡发生的机制却知之甚少。为深入了解这些机制，一个重要步骤可能是收集脊柱两侧竖脊肌体积以及将这些肌肉与体表分隔开的皮肤和皮下脂肪（皮褶）厚度的解剖学数据。为此，使用磁共振（MR）成像较为合适。
收集脊柱侧弯患者脊柱侧弯处竖脊肌和皮褶厚度的解剖学信息。
在一项观察性回顾性研究中，分析了过去5年在一家儿科医院接受治疗的脊柱侧弯患者的MR图像。
图像取自青少年特发性脊柱侧弯患者。
对于15名患者（第一组），使用了三种临床采集方案。要求五名研究人员对每种方案获得的图像对比度进行评分。所有评估均在同一台显示器上进行，其设置无任何变化。对于提供最佳对比度的MR序列，从17名患者（第二组）获得了25个完整成像的脊柱侧弯偏差。使用图像处理软件包对每个可用图像上脊柱两侧的竖脊肌进行手动分割，以确定其体积。还测量了皮褶厚度；首先在竖脊肌上从C7到L3定期测量，然后在每个曲线顶点的中心部位测量。
对于第一组，发现自旋回波（SE-T1）能提供最佳对比度以识别单个肌肉的轮廓。使用该序列，对完整成像的脊柱侧弯曲线（第二组）的分析显示，背部肌肉体积在凹侧比凸侧大14倍的情况出现了14次，大11倍的情况出现了11次。当将每条曲线的长度归一化然后分成三个相等区域时，肌肉体积在顶点处大11倍（凹侧大6倍），在上方大7倍，在下方大7倍（两个位置凹侧均大4倍）。从C7到L3，每位患者的平均皮褶厚度在7.3毫米至16.3毫米之间。平均而言，T3和T12之间的厚度<10毫米，但在L3水平处变大。在每个脊柱侧弯偏差的顶点处，凹侧的皮褶厚度总是更大，并且随着与顶点距离的增加，差异逐渐减小。
青少年特发性脊柱侧弯患者中，背部肌肉体积较大在凹侧比在凸侧略为常见。差异在曲线顶点处更为常见。顶点区域凹侧的皮褶厚度总是更大。
