Radiogrammetry

a semiquantitative method of bone mineral analysis in which measurements are derived from radiographs, most commonly through determination of the metacarpal index. This method is useful in measuring bone mineral content of the appendicular skeleton but is of limited clinical value in assessing the bone status in the axial skeleton. Fine-detail radiographs are required, on which the cortical thickness is compared to the total bone width in the mid-diaphysis of at least two metacarpal bones.

The technique is simple and widely available, requiring the ability only to take reproducible radiographs and to make fine calibre measurements. Small changes in the endosteal and periosteal cortices may be found by serial measurements. However, radiogrammetry does not provide reliable measurements of absolute bone mineral content and does not measure intracortical bone porosity. Therefore, it yields information only on relative changes in bone volume.