Figure 1: Acquisition and analysis of the MCP BMD at the first visit. The machine acquires the hand region (a) that has to be analysed manually. Then the operator defines the borders of the bone working in a magnified image with the software of the densitometer, obtaining a mask visible in the second image (white line) (b). Then he creates a ROI (region of interest, arrow) that includes the MCP rim, the head of the metacarpal bone, and the basis of the proximal phalange (c). Both the mask and the ROI are then saved and always used to assess BMD changes of each patient.