Frequency domain imaging of cancellous bone

The cancellous structure in the distal third of the radius has been assessed and described using frequency domain techniques to analyse the spatial characteristics of the two dimensions of cancellous bone in single AP X-rays. These techniques are particularly useful to quantify changes in orientation and amount of trabeculae. Corrections for the wide variations in X-ray contrast can be easily carried out, by normalizing the summation of the magnitudes from the relevant frequencies. Paired images from a group of 10 patients were examined, and experiments to isolate the window effect from frequencies truly related to the cancellous structure were performed, based on the rotation of the images on the scanner and analysis of direction sensitive parameters. This procedure helped in the differentiation and determination of the characteristics of the image that are truly related to the cancellous bone structure from those due to the window effect inevitably present in any image