Department of Radiology and Advanced Diagnostic Imaging Center, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Faculty of Health Sciences Technology, HRH Princess Chulabhorn College of Medical Science, Bangkok, Thailand.
Acta Radiol. 2021 Aug;62(8):1052-1062. doi: 10.1177/0284185120951963. Epub 2020 Aug 27.
We hypothesized that axial-loaded magnetic resonance imaging (MRI), modified with the use of a cushion placed behind the lower back (i.e. BS-MRI method), would simulate the standing position more accurately than an axial-loaded MRI without a cushion back support (BS).
To determine whether the BS-MRI method demonstrated similar morphologies on intervertebral disc (IVD), dural sac, and spinal curvature as those detected on 90° standing MRIs in individuals with suspected spinal stenosis.
Twenty-five subjects underwent a BS-MRI, as well as axial-loaded and standing MRI studies. Outcome measures were four radiographic parameters of the lumbar spine: IVD height (DH); dural sac cross-sectional area (DCSA); and spinal curvature (i.e. lumbar lordosis [LL] and L1-L3-L5 angle [LA]).
Major differences (>5%) between standing MRI and BS-MRI methods were observed in DCSA, DH, and LL. Major differences between standing and axial loaded MRIs were observed only in DCSA and LA. Although BS-MRIs demonstrate an image of the lumbar spine curvature (i.e. LA) which is closer to that when standing than axial-loaded MRIs, it is likely to overestimate both narrowing of dural sac and extent of LL.
Using a compression device with a BS to simulate weight-bearing on the lumbar spine is not recommended due to: (i) overestimation of the narrowing of the dural sac and extent of LL; and (ii) underestimation of loss of disc height. Supine axial-loading produced DCSA and DH which were strongly correlated with those detected with standing MRIs. Exceptions were that LL and LA were underestimated.
我们假设，通过在腰部下方放置一个靠垫来对轴向加载磁共振成像（MRI）进行改良（即 BS-MRI 方法），可以比不使用靠垫背部支撑（BS）的轴向加载 MRI 更准确地模拟站立姿势。
确定 BS-MRI 方法是否在疑似脊柱狭窄的个体中，在椎间盘（IVD）、硬脑膜囊和脊柱曲度方面显示出与 90°站立 MRI 相同的形态。
25 名受试者接受了 BS-MRI 以及轴向加载和站立 MRI 研究。测量指标为腰椎的四个影像学参数：IVD 高度（DH）；硬脑膜囊横截面积（DCSA）；脊柱曲度（即腰椎前凸[LL]和 L1-L3-L5 角[LA]）。
在 DCSA、DH 和 LL 方面，站立 MRI 和 BS-MRI 方法之间存在较大差异（>5%）。仅在 DCSA 和 LA 方面，站立和轴向加载 MRI 之间存在较大差异。尽管 BS-MRI 显示的腰椎曲度（即 LA）图像比轴向加载 MRI 更接近站立时的图像，但它可能会高估硬脑膜囊狭窄和 LL 的程度。
不建议使用 BS 压缩装置来模拟腰椎负重，因为：（i）高估硬脑膜囊狭窄和 LL 程度；和（ii）低估椎间盘高度损失。仰卧位轴向加载产生的 DCSA 和 DH 与站立 MRI 检测到的 DCSA 和 DH 具有很强的相关性。例外的是，LL 和 LA 被低估了。
