The microarchitecture of trabecular bone is well known to be key to bone strength and thus resistance to fracture. The current methodology for micromorphometry involves the quantitative assessment of parameters such as bone fraction, trabecular thickness, star volume and intercept length on the basis of microphotographs of polished sections of bone by means of stereologic analysis. The hypothesis underlying the proposed work is that nuclear magnetic resonance imaging at microscopic dimensions (""""""""NMR microscopy"""""""") is an alternative and potentially superior investigational tool for the derivation of morphometric parameters from the resulting digital images. The suitability of the technique is enhanced by the intrinsically high contrast between the trabeculae and the protons in the marrow spaces. Another unique feature of the technique is its ability to provide measurements in any arbitrary orientation from three-dimensional isotropic data sets by retrospective data rearrangement. The investigators' preliminary work provides evidence for the feasibility of NMR microscopy as a quantitative morphologic analysis method in vitro at 9.4T and in vivo at 1.5T. The principal aim of this project is to further develop and evaluate NMR microscopy for the study of trabecular architecture in vitro on cadaver specimens from the human patella and in vivo in normal subjects at the same anatomic location. For this purpose computer algorithms will be generated for the unbiased measurement of microarchitectural parameters including trabecular area and thickness, trabecular density, star volume and fabric tensor and to validate the resultant parameters against those derived from conventional stereology on anatomic sections. Another aim is to ascertain the statistical association of these parameters in cadaver specimens of human trabecular bone with Young's modulus.
A final aim consists of exploring the feasibility of measuring these parameters in vivo on a suitably modified whole-body NMR scanner, the study of the age dependence of these parameters and their correlation with bone mineral density.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
1R01AR041443-01A1
Application #
3161890
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1993-01-01
Project End
1995-12-31
Budget Start
1993-01-01
Budget End
1993-12-31
Support Year
1
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Chen, Cheng; Jin, Dakai; Liu, Yinxiao et al. (2016) Trabecular bone characterization on the continuum of plates and rods using in vivo MR imaging and volumetric topological analysis. Phys Med Biol 61:N478-N496
Wald, Michael J; Magland, Jeremy F; Rajapakse, Chamith S et al. (2012) Predicting trabecular bone elastic properties from measures of bone volume fraction and fabric on the basis of micromagnetic resonance images. Magn Reson Med 68:463-73
Bhagat, Yusuf A; Rajapakse, Chamith S; Magland, Jeremy F et al. (2011) On the significance of motion degradation in high-resolution 3D ?MRI of trabecular bone. Acad Radiol 18:1205-16
Wright, Alexander C; Lemdiasov, Rostislav; Connick, Thomas J et al. (2011) Helmholtz-pair transmit coil with integrated receive array for high-resolution MRI of trabecular bone in the distal tibia at 7T. J Magn Reson 210:113-22
Sundberg, John P; McElwee, Kevin J; Carroll, Joseph M et al. (2011) Hypothesis testing: CTLA4 co-stimulatory pathways critical in the pathogenesis of human and mouse alopecia areata. J Invest Dermatol 131:2323-4
Wald, Michael Jeffrey; Magland, Jeremy Franklin; Rajapakse, Chamith Sudesh et al. (2010) Structural and mechanical parameters of trabecular bone estimated from in vivo high-resolution magnetic resonance images at 3 tesla field strength. J Magn Reson Imaging 31:1157-68
Magland, Jeremy F; Rajapakse, Chamith S; Wright, Alexander C et al. (2010) 3D fast spin echo with out-of-slab cancellation: a technique for high-resolution structural imaging of trabecular bone at 7 Tesla. Magn Reson Med 63:719-27
Wehrli, Felix W; Rajapakse, Chamith S; Magland, Jeremy F et al. (2010) Mechanical implications of estrogen supplementation in early postmenopausal women. J Bone Miner Res 25:1406-14
Rajapakse, Chamith S; Magland, Jeremy F; Wald, Michael J et al. (2010) Computational biomechanics of the distal tibia from high-resolution MR and micro-CT images. Bone 47:556-63
Magland, Jeremy F; Jones, Catherine E; Leonard, Mary B et al. (2009) Retrospective 3D registration of trabecular bone MR images for longitudinal studies. J Magn Reson Imaging 29:118-26

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