Figure 3
An example of an early axial spondyloarthritis (SpA) patient (a–d). Transaxial images of bone SPECT (a) and SPECT/CT (b) demonstrated uptake in SI joints with high SIS ratios of 1.86 (right) and 1.62 (left). The posterior image of bone scintigraphy (c) showed normal SIS ratios of 1.11 (right) and 1.09 (left). The anterior image of plain radiography (d) showed SI joint grades of 1 (right) and 0 (left). An example of a control subject (e–h). Transaxial images of bone SPECT (e) and SPECT/CT (f) showed comparable SIS ratios of 1.04 (right), and 1.22 (left). The posterior image of bone scintigraphy (g) showed normal SIS ratios of 1.09 (right) and 0.91 (left). The anterior image of plain radiography (h) showed an SI joint grade of 0 (both sides).