Department of Radiology, Campus Mitte, Charité - Universitätsmedizin Berlin, Humboldt-Universität and Freie Universität Berlin, Charitéplatz 1, 10117, Berlin, Germany.
Spine Surgery, Center for Musculoskeletal Surgery, Radiology, Charité - Universitätsmedizin Berlin, Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany.
Eur Radiol. 2021 Dec;31(12):9390-9398. doi: 10.1007/s00330-021-08028-z. Epub 2021 May 15.
To analyze the two major components of the intervertebral disc (IVD) in an ex vivo phantom, as well as age-related changes in patients.
Collagen and chondroitin sulfate were imaged at different concentrations in agar solution. Age-related changes in disc density were retrospectively analyzed in normal-appearing discs in dual-energy computed tomography (DECT) images from a patient cohort with various spinal pathologies (n = 136). All computed tomography (CT) scans were acquired using single-source DECT at 80 and 135 kVp with automatic exposure calculation. In 136 patients, the attenuation of normal-appearing discs on collagen/chondroitin maps (cMaps) correlated with the patients' age with Pearson's r using standardized regions of interest in the anterior anulus fibrosus (AAF) and nucleus pulposus (NP).
DECT collagen mapping revealed concentration-dependent Hounsfield units (HU) of IVD components. For collagen, we found Pearson's r = 0.9610 (95% CI 0.6789-0.9959), p = 0.0023 at 120 kVe, and r = 0.8824 (95% CI 0.2495-0.9871), p = 0.0199 in cMap. For chondroitin sulfate, Pearson's r was 0.9583 (95% CI 0.6603-0.9956), p = 0.0026 at 120 kVp, and r = 0.9646 (95% CI 0.7044-0.9963), p = 0.0019 in cMap. Analysis of normal-appearing IVDs revealed an inverse correlation of density with age in the AAF: Pearson's r = - 0.2294 at 135 kVp (95% CI - 0.4012 to - 0.04203; p=0.0141) and r = - 0.09341 in cMap (95% CI - 0.2777 to 0.09754; p = 0.0003). In the NP, age and density did not correlate significantly at 135 kVp (p = 0.9228) and in cMap (p = 0.3229).
DECT-based collagen mapping allows microstructural analysis of the two main intervertebral disc components-collagen and chondroitin sulfate. IVD density declines with age, presumably due to a reduction in collagen and chondroitin sulfate content. Age-related alterations of disc microstructure appear most pronounced in the AAF.
• DECT-based collagen mapping allows precise analysis of the two main intervertebral disc components-collagen and chondroitin sulfate. • Intervertebral disc (IVD) density declines with age, presumably due to a reduction in collagen and chondroitin sulfate content. • Age-related alterations of disc microstructure are most pronounced in the anterior anulus fibrosus (AAF).
分析离体模型中椎间盘（IVD）的两个主要成分，以及患者的年龄相关性变化。
在琼脂溶液中以不同浓度对胶原蛋白和硫酸软骨素进行成像。对来自患有各种脊柱病变的患者队列的双能 CT（DECT）图像中表现正常的椎间盘的密度进行回顾性分析（n=136）。所有 CT 扫描均在具有自动曝光计算的单源 DECT 上以 80 和 135 kVp 采集。在 136 名患者中，在胶原蛋白/软骨素图谱（cMap）上正常椎间盘的衰减与患者年龄呈正相关，使用前纤维环（AAF）和核髓（NP）的标准化感兴趣区进行 Pearson r 分析。
DECT 胶原蛋白图显示了 IVD 成分的浓度依赖性 Hounsfield 单位（HU）。对于胶原蛋白，我们发现在 120 kVe 时，Pearson r = 0.9610（95%CI 0.6789-0.9959），p = 0.0023，在 cMap 中 r = 0.8824（95%CI 0.2495-0.9871），p = 0.0199。对于硫酸软骨素，Pearson r 为 0.9583（95%CI 0.6603-0.9956），p = 0.0026 在 120 kVp 时，在 cMap 中 r = 0.9646（95%CI 0.7044-0.9963），p = 0.0019。对表现正常的 IVD 进行分析表明，在 AAF 中，密度与年龄呈负相关：在 135 kVp 时，Pearson r = -0.2294（95%CI -0.4012 至 -0.04203；p=0.0141），在 cMap 中 r = -0.09341（95%CI -0.2777 至 0.09754；p=0.0003）。在 135 kVp 时（p=0.9228）和 cMap 中（p=0.3229），NP 中的年龄和密度与年龄无显著相关性。
基于 DECT 的胶原蛋白图可实现对椎间盘的两个主要成分-胶原蛋白和硫酸软骨素的微观结构分析。IVD 密度随年龄的增长而降低，可能是由于胶原蛋白和硫酸软骨素含量减少所致。椎间盘微观结构的年龄相关性改变在 AAF 中最为明显。
基于 DECT 的胶原蛋白图可精确分析椎间盘的两个主要成分-胶原蛋白和硫酸软骨素。
IVD 密度随年龄的增长而降低，可能是由于胶原蛋白和硫酸软骨素含量减少所致。
年龄相关性椎间盘微观结构改变在 AAF 中最为明显。
