Figure 1From: The usefulness of bone SPECT/CT imaging with volume of interest analysis in early axial spondyloarthritisThe volume of interest (VOI) of sacroiliac (SI) joint and sacrum for SI joint to sacrum (SIS) uptake ratio. The VOI images of SI joint (a) and sacrum (b) defined in transxial image of bone single positron emission computed tomography-computed tomography (SPECT/CT). Three-dimensional (3D) reconstructed VOI images of SI joint (c) and sacrum (d) used to calculate the SIS uptake ratio in bone SPECT/CT.Back to article page