Cortes Daniel H, Magland Jeremy F, Wright Alexander C, Elliott Dawn M
Department of Biomedical Engineering, University of Delaware, Newark, Delaware, USA.
Magn Reson Med. 2014 Jul;72(1):211-9. doi: 10.1002/mrm.24895. Epub 2013 Jul 31.
This study aims to: (1) measure the shear modulus of nucleus pulposus (NP) in intact human vertebra-disc-vertebra segments using a magnetic resonance elastography setup for a 7T whole-body scanner, (2) quantify the effect of disc degeneration on the NP shear modulus measured using magnetic resonance elastography, and (3) compare the NP shear modulus to other magnetic resonance-based biomarkers of dis degeneration.
Thirty intact human disc segments were classified as normal, mild, or severely degenerated. The NP shear modulus was measured using a custom-made setup that included a novel inverse method less sensitive to noisy displacements. T2 relaxation time was measured at 7T. The accuracy of these parameters to classify different degrees of degeneration was evaluated using receiver operating characteristic curves.
The magnetic resonance elastography measure of shear modulus in the NP was able to differentiate between normal, mild degeneration, and severe degeneration. The T2 relaxation time was able to differentiate between normal and mild degeneration, but it could not distinguish between mild and severe degeneration.
This study shows that the NP shear modulus measured using magnetic resonance elastography is sensitive to disc degeneration and has the potential of being used as a clinical tool to quantify the mechanical integrity of the intervertebral disc.
本研究旨在：（1）使用适用于7T全身扫描仪的磁共振弹性成像装置测量完整人体椎间盘-椎体节段中髓核（NP）的剪切模量；（2）量化椎间盘退变对使用磁共振弹性成像测量的NP剪切模量的影响；（3）将NP剪切模量与其他基于磁共振的椎间盘退变生物标志物进行比较。
30个完整的人体椎间盘节段被分类为正常、轻度或重度退变。使用定制装置测量NP剪切模量，该装置包括一种对噪声位移不太敏感的新型反演方法。在7T下测量T2弛豫时间。使用受试者工作特征曲线评估这些参数对不同程度退变进行分类的准确性。
NP中剪切模量的磁共振弹性成像测量能够区分正常、轻度退变和重度退变。T2弛豫时间能够区分正常和轻度退变，但无法区分轻度和重度退变。
本研究表明，使用磁共振弹性成像测量的NP剪切模量对椎间盘退变敏感，有潜力用作量化椎间盘机械完整性的临床工具。
