Multi-Detector Row CT Imaging of Vertebral Microstructure for Evaluation of Fracture Risk

Abstract

We applied MDCT for in vivo evaluation of the microarchitecture of human vertebrae. Microstructure parameters, such as structure model index, Euler's number, and bone volume fraction, revealed higher relative risk for prevalent vertebral fracture than did BMD obtained by DXA. Thus, microstructure analysis by MDCT, together with simultaneously obtained volumetric BMD values, is useful for clinical assessment of fracture risk.Introduction: BMD measurement by DXA alone has limitations in predicting fracture, and methods for clinical assessment of bone quality, such as microstructure, are awaited. This study was undertaken to examine the applicability of multidetector row CT (MDCT) for in vivo evaluation of trabecular microstructure. Materials and Methods: Optimal conditions for MDCT scanning were determined at a spatial resolution of 250 × 250 × 500 m, using CT data of excised human vertebra specimens as a reference. We analyzed the trabecular microstructure of the vertebrae of 82 postmenopausal women (55-76 years old), including 39 women with and 43 without a recent vertebral fracture. Results: Microstructure indices obtained by MDCT scanning revealed higher relative risk for prevalent vertebral fracture (OR: 16.0 for structure model index, 13.6 for bone volume fraction, and 13.1 for Euler's number) than did spinal BMD obtained by DXA (OR: 4.8). MDCT could also provide volumetric BMD data, which had higher diagnostic value (OR: 12.7) than did DXA. Conclusion: Vertebral microarchitecture can be visualized by MDCT, and microstructure parameters obtained by MDCT, together with volumetric BMD, provided better diagnostic performance for assessing fracture risk than DXA measurement.

Quantitative MRI for the assessment of bone structure and function

“…the distal radius and tibia (14,15). The rapid diffusion of multi-detector CT systems also opens opportunities for TB structure analysis in the axial skeleton (16) although radiation exposure is a concern. However, remarkable progress in high-resolution MRI during the past 10 years now offers a new tool for TB structure assessment [reviews: (8,(17)(18)(19)(20)].…”

“…A further potential motivation is the study of the structural manifestations of metabolic bone disease such as renal osteodystropy (166). Evidence for these developments is the rapid growth of the clinical literature (8,83,84,127,145,165,(167)(168)(169)(170)(171)(172) and also, to a lesser extent, the increased use of CT to characterize TB (14)(15)(16)(173)(174)(175)(176)(177).…”

Application of quantitative computed tomography for assessment of trabecular bone mineral density, microarchitecture and mechanical property

“…The BV/TV, Tb.N, Tb.Th, and Tb.Sp, connectivity and structure model index (SMI) are calculated two-dimensionally using plate model assumptions [131,132] or direct three-dimensional measures [133]. Due to the lower spatial resolution comparing with the pQCT or μQCT, the partial volume effect is relatively large.…”

“…Studies have shown a moderate correlation between the MDCT and μQCT in trabecular microstructure assessment (r=.44-0.99) [132,134]. The advantage of the MDCT technique is that both the central or peripheral regions of the skeleton can be assessed, such as the spine, proximal femur and extremity [132,133,135]. Studies indicated that the BV/TV and SMI measured from lumbar spine by MDCT provided a superior result in predicting fracture risk and therapeutic evaluation than BMD measurement with DXA or QCT [133,136].…”

“…The advantage of the MDCT technique is that both the central or peripheral regions of the skeleton can be assessed, such as the spine, proximal femur and extremity [132,133,135]. Studies indicated that the BV/TV and SMI measured from lumbar spine by MDCT provided a superior result in predicting fracture risk and therapeutic evaluation than BMD measurement with DXA or QCT [133,136]. Currently, the bone microarchitecture assessment of the lumbar spine by using MDCT is still limited due to radiation dose concern.…”