Error analysis of the microradiographic determination of mineral content in mineralised tissue slices

The microradiographic method, used to measure the mineral content in slices of mineralised tissues as a function of position, is analysed. The total error in the measured mineral content is split into systematic errors per microradiogram and random noise errors. These errors are measured quantitatively. Predominant contributions to systematic errors appear to be x-ray beam inhomogeneity, the determination of the step wedge thickness and stray light in the densitometer microscope, while noise errors are under the influence of the choice of film, the value of the optical film transmission of the microradiographic image and the area of the densitometer window. Optimisation criteria are given. We used these criteria, together with the requirement that the method be fast and easy, to build an optimised microradiographic system.