|Abstract or Summary
- Bone strength and fracture resistivity are related to a variety of factors encompassed in what is referred to as bone quality. However, bone quality is not a well-defined concept; therefore individual fracture risk cannot be predicted accurately, and osteoporosis treatment monitoring remains di cult. Clinically available imaging modalities use bone mineral density (BMD) as a proxy for bone strength despite its well-known shortcomings, and current research seeks to link microstructural measurements to bone strength. This research investigates the pre-clinical application of a new imaging modality, Medipix all resolution system computed tomography (MARS CT), for diagnostic imaging assessment of bone quality. Data from four cadaveric femoral necks was acquired with MARS CT, computed tomography (CT), dual energy x-ray absorptiometry (DXA), and high resolution peripheral computed tomography (HR-pQCT). Results were analyzed to test whether MARS CT could provide information equivalent to that currently used to investigate bone quality, as well as additional 3D material information and other related quantities.Four cadaveric femurs were scanned with CT, DXA, and HRpQCT to obtain clinically relevant measurements including bone mineral density (BMD) and microstructural measurements of the femoral neck. The femurs were sectioned prior to HRpQCT imaging to meet the size limitations of HRpQCT and MARS CT. The specimens were then shipped to the University of Otago in Christchurch, New Zealand for analysis with MARS CT. Since these were the first human femoral necks scanned with MARS CT, a scanning protocol was developed and optimized. Finally, the femoral neck specimens were scanned with MARS CT, and the data was analyzed and compared with the results from other modalities.This research shows that MARS CT can quantify various indicators related to bone quality. These include, but are not limited to: cortical, trabecular, and total-bone BMD; trabecular thickness and spacing; and cortical thickness. Images of the calcium hydroxyapatite contained in the specimens were also obtained and used to measure slice-specific trabecular BMD. The comparability of the MARS results with the HR-pQCT results was limited by air in the trabecular spacing, contouring differences between MARS and HR-pQCT images, and the difference in voxel size. These issues served as a lesson in methodology for future cross-modality bone quality studies. This research established a baseline for what can be accomplished with the current MARS scanner and will lead to future refinement of MARS CT and improvement of bone quality assessment.
- Bone strength and fracture resistivity are related to a variety of factors encompassed in what is referred to as bone quality. However