AbstractID: 7566 Title: Imaging Bone Mineralization using Coherently
Scattered X Rays
As metabolic bone diseases progress, compositions of both the marrow space and bone tissue itself may change. Coherent-scatter (CS)
properties depend on the molecular structure of the scatterer and are, therefore, sensitive to changes in material composition. Unlike
established techniques for assessing bone mineral density, which must assume non-varying bone composition, coherent-scatter
analysis (CSA) provides a means for distinguishing bone mineral from its collagen matrix. A method is described for obtaining
quantitative information from CS cross-sections and for producing tomographic maps of the spatial distribution of each material in a
conglomerate. The precision and accuracy were assessed in phantoms and bone specimens, using both projection and CT
measurements. For the projection method, mineral concentrations were measured over a range of 0-0.400 g/cm3 to within 2% (2%
precision). In phantoms with varying quantities of collagen and mineral, the ratios measured were found to be accurate within 2%-4%
(4% precision). Material-specific images were generated for a bone-mimicking phantom and a porcine bone, showing the spatial
distribution of each tissue in an axial slice. Contrast in these images reflects the concentration (in g/cm3) of each material at every
point in the image. In the phantom, HA and collagen concentrations were measured within 2% of the known value (3% precision). The
collagen-mineral ratio determined from material-specific images of the bone specimen suggested a 10% under mineralization. It is
concluded that coherent-scatter measurements can form the basis of a viable technique for non-destructive bone analysis, both in the
laboratory and in situ.