Fig. 4

Illustration of BTU measurements with IntroSPECT©. Top left: Axial view of the talus surface. Red is the measurement box, placed in the six square grid for a measurement. The lesion is visible in purple. Top right: Sagital view with the center through the talar dome. The red box shows the measurement volume with the included bone. Low left: Sagital view. This time the red box includes only the center of the talus to make the last measurement in the talar center. In this measurement the volume is defined but not the position. Top left: Axial view on the talus surface with the measurement voxel box (red). The six squares divide the surface of the talus. Purple is the plane for adjustment of the patients foot position. Green and red are the plane which go through the talus. Top right: Sagittal view. Red is the measurement volume. It shows all the bone which is included into the measurement. Low left: Sagittal view. Red is the measurement volume (VOI) in the talus centre. The volume is defined, the position is not