Magnetic Resonance Imaging Evaluation of Biomechanical Effects of Axial Loading on the Lumbar Spine

Abstract

Background: MRI techniques of the lumbar spine have not provided data on the effect of gravity on the spine and on the relationship of anatomic structures during its action. Because conventional MRI examinations of the spine are usually performed in the supine position these are often exacerbated by standing upright and are not evident in the supine position the loading conditions differ from those known to cause symptoms in patients with lumbar instability. Axial loading imaging may improve diagnostics in the clinical management of LBP and lead to appropriate treatment decisions. Objective: The aim of this study is to determine the significance of alMRI in detecting the morphologic changes of the lumbar spine caused by axial loading and to compare it with conventional MRI images of the lumbar spine without loading. Methods: The study was conducted as a prospective, descriptive clinical trial. Imaging was performed with a MRI 1.5 T in the head-first supine position. Imaging was performed in two acts: without load and under load. Loading for alMRI was performed with the DynaWell L-Spine device. The onset of loading was 10 minutes before the start of alMRI. The loading continued throughout the imaging procedure. The height of the IV, AP and LL diameters of IV, IV disk surface area, DSCA and width of the IV foraminas before and under load was measured. Results: After evaluating the changes in the height and size of the lumbar disks, the size of the DSCA, and the narrowing of the intervertebral foramina significant differences were found between the images before and after axial loading. Conclusion alMRI provides information on morphological changes of all segments of the lumbar spine. This data represents significant information that can lead to more accurate and effective treatment of LBP.

Different Load-Induced Alterations in Intervertebral Discs Between Low Back Pain Patients and Controls

“…[15][16][17][18][19] Thereto, it is known that axial load on the lumbar spine generates instant macroscopical IVD changes in both patients and controls, such as increased disc angle, decreased disc height as well as bulging of the posterior part of the disc. 15,[20][21][22][23][24][25] Thus, since load affects both morphologic and quantitative parameters of the IVDs it is theoretically appealing to compare the load-induced effect on LBP patients with healthy controls to investigate if quantitative patterns, specific for LBP patients, can be uncovered using the effect of axial load.…”

“…In vitro experiments as well as studies on humans have shown that spinal loading during MRI influences quantitative IVD parameters and it has been demonstrated that grade of IVD degeneration affects load-induced alteration of T2-map values 15–19 . Thereto, it is known that axial load on the lumbar spine generates instant macroscopical IVD changes in both patients and controls, such as increased disc angle, decreased disc height as well as bulging of the posterior part of the disc 15,20–25 . Thus, since load affects both morphologic and quantitative parameters of the IVDs it is theoretically appealing to compare the load-induced effect on LBP patients with healthy controls to investigate if quantitative patterns, specific for LBP patients, can be uncovered using the effect of axial load.…”