Moire patterns from plain radiographs of trabecular bone

Trabecular bone strength and integrity are related to both bone mass and architecture. Current methods for assessing architecture in vivo are limited. This study investigates the synthesis of moire patterns as a potential means for assessing trabecular bone. Plain radiographs of the human calcaneus are digitized, thresholded, rotated and nonlinearly superimposed to derive a moire pattern associated with the original radiographic image. The moire patterns may provide an enhanced means for classifying and analyzing trabecular bone structures compared to or in conjunction with individual (non-superimposed) radiographic images. Another feature of this paper is the description of a local thresholding method for segmenting the radiograph into a binary (bone/no-bone) image. This is potentially useful for stereological analysis of radiographs.