The use of digital X-ray to monitor decalcification in sheep femora

The need for a simple and precise method of evaluating bone density in the clinical and research environment is clear and the advent of digital radiography offers new opportunities in the use of X-ray to provide this information. In this paper the use of an Aluminium step wedge in digital radiography to evaluate bone density in decalcified sheep femur specimens is evaluated. Ten specimens were decalcified over 26 days in Ethylene Diaminetetra Acetic Acid (EDTA). X-rays of the samples were corrected for imaging inhomogeneities and calibrated using an aluminum step wedge to obtain an Aluminium-equivalent thickness. Their mineral density was also assessed using micron-level Computed Tomography (CT) and ash-weight as a gold standard. Comparison of the results show the correlation between X-ray Aluminium-equivalent thickness and ash-weight to be significant (R² = 0.9) and superior to other techniques. We conclude that calibrated digital X-ray offers the potential to provide accurate, quantitative density information.