Orthopaedic Biomechanics Laboratory, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
J Neurosurg Spine. 2010 Sep;13(3):367-70. doi: 10.3171/2010.3.SPINE09576.
Noninvasive evaluation of metastatic disease in the spine has generally been limited to 2D qualitative or semiquantitative analysis techniques. This study aims to develop and evaluate a highly automated micro-CT-based quantitative analysis tool that can measure the architectural impact of metastatic involvement in whole vertebrae. Micro-CT analysis of rat whole vertebrae was conducted using a combination of demons deformable registration, level set curvature evolution, and intensity based thresholding techniques along with upsampling and edge enhancement techniques. The algorithm was applied to 6 lumbar vertebrae (L1-3) from 6 rnu/rnu rats (3 healthy rats and 3 with metastatic involvement). Osteolytic metastatic involvement was modeled via MT1 human breast cancer cells. Excellent volumetric concurrency was achieved in comparing the automated micro-CT-based segmentations of the whole vertebrae, trabecular centrums, and individual trabecular networks to manual segmentations (98.9%, 96.1%, and 98.3%, respectively; 6 specimens), and the automated segmentations were achieved in a fraction of the time. The algorithm successfully accounted for discontinuities in the cortical shell caused by vasculature and osteolytic destruction. As such, this work demonstrates the potential of this highly automated segmentation tool to permit rapid precise quantitative structural analysis of the spine with minimum user interaction in the analysis of both healthy and pathological (metastatically involved) vertebrae. Future optimization and the incorporation of lower-resolution imaging parameters may allow automated analysis of clinical CT-based measures in addition to preclinical micro-CT-based analyses of the structural impact and progression of pathological processes in the spine.
非侵入性评估脊柱转移瘤的方法通常仅限于 2D 定性或半定量分析技术。本研究旨在开发和评估一种高度自动化的基于 micro-CT 的定量分析工具，该工具可以测量整个椎体中转移性受累的结构影响。使用 demons 可变形配准、水平集曲率演化和基于强度的阈值技术以及上采样和边缘增强技术对大鼠整个椎体进行 micro-CT 分析。该算法应用于 6 只 rnu/rnu 大鼠（3 只健康大鼠和 3 只转移性受累大鼠）的 6 个腰椎（L1-3）。通过 MT1 人乳腺癌细胞模拟溶骨性转移性受累。与手动分割相比，自动分割实现了整个椎体、骨小梁中心和单个骨小梁网络的体积一致性非常高（分别为 98.9%、96.1%和 98.3%；6 个样本），并且自动分割的时间仅为手动分割的一小部分。该算法成功地考虑了由血管和溶骨性破坏引起的皮质壳的不连续性。因此，这项工作证明了这种高度自动化分割工具的潜力，它可以在分析健康和病理（转移性受累）椎体时，通过最小的用户交互，快速准确地进行脊柱的定量结构分析。未来的优化和更低分辨率成像参数的纳入可能允许对临床 CT 测量值进行自动分析，以及对脊柱中病理过程的结构影响和进展进行基于 micro-CT 的预临床分析。
