The proposed project aims to develop techniques to quantify trabecular bone density and structure using Magnetic Resonance (MR) techniques. The difference between the magnetic susceptibility of trabecular bone and bone marrow results in a decrease in the marrow relaxation time, T2*, which is proportional to the trabecular density and spatial distribution. This reduction in T2* will be quantified using human bone specimens and related to the surrounding trabecular density measured using quantitative computed tomography (QCT), and to the mechanical strength of the specimens. Image analysis techniques will be developed in order to characterize trabecular pattern in high resolution MR images. The perimeter-to-area ratio, trabecular spacing, and the fractal dimension of the trabecular boundary will be derived along different planes, and trabecular bone anisotropy will be deduced. The con-elation between these measures of structure and mechanical strength of the specimens and histomorphometric estimates of the mean trabecular spacing and dimensions will be derived. After establishing the effectiveness of these techniques, a case control study to determine the efficacy of these outcome variables as predictors of fracture risk will be conducted in postmenopausal women (60-70 years) with and without vertebral fractures. Trabecular bone density of the lumbar spine will be assessed using QCT. T2* will be measured using MR imaging and bone structure will be quantified using the image analysis techniques developed. Logistic regression will be used to determine whether these outcome variables are better predictors of relative fracture risk compared to measures of bone density alone.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Modified Research Career Development Award (K04)
Project #
5K04AR001903-02
Application #
2077443
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1993-05-01
Project End
1998-04-30
Budget Start
1994-05-01
Budget End
1995-04-30
Support Year
2
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of California San Francisco
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
073133571
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Majumdar, S; Link, T M; Millard, J et al. (2000) In vivo assessment of trabecular bone structure using fractal analysis of distal radius radiographs. Med Phys 27:2594-9
Majumdar, S; Link, T M; Augat, P et al. (1999) Trabecular bone architecture in the distal radius using magnetic resonance imaging in subjects with fractures of the proximal femur. Magnetic Resonance Science Center and Osteoporosis and Arthritis Research Group. Osteoporos Int 10:231-9
Majumdar, S; Lin, J; Link, T et al. (1999) Fractal analysis of radiographs: assessment of trabecular bone structure and prediction of elastic modulus and strength. Med Phys 26:1330-40
Link, T M; Majumdar, S; Lin, J C et al. (1998) A comparative study of trabecular bone properties in the spine and femur using high resolution MRI and CT. J Bone Miner Res 13:122-32
Link, T M; Majumdar, S; Augat, P et al. (1998) In vivo high resolution MRI of the calcaneus: differences in trabecular structure in osteoporosis patients. J Bone Miner Res 13:1175-82
Majumdar, S (1998) A review of magnetic resonance (MR) imaging of trabecular bone micro-architecture: contribution to the prediction of biomechanical properties and fracture prevalence. Technol Health Care 6:321-7
Link, T M; Majumdar, S; Lin, J C et al. (1998) Assessment of trabecular structure using high resolution CT images and texture analysis. J Comput Assist Tomogr 22:15-24
Link, T M; Majumdar, S; Augat, P et al. (1998) Proximal femur: assessment for osteoporosis with T2* decay characteristics at MR imaging. Radiology 209:531-6
Ouyang, X; Majumdar, S; Link, T M et al. (1998) Morphometric texture analysis of spinal trabecular bone structure assessed using orthogonal radiographic projections. Med Phys 25:2037-45
Augat, P; Link, T; Lang, T F et al. (1998) Anisotropy of the elastic modulus of trabecular bone specimens from different anatomical locations. Med Eng Phys 20:124-31

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