Tomosynthesis performance compared to radiography and computed tomography for sacroiliac joint structural damage detection in patients with suspected axial spondyloarthritis

•Tomosynthesis was better than radiography in detecting sacroiliitis.•Using tomosynthesis instead of radiography increased the sacroiliitis detection rate by 50% and halved the number of false positives.•Tomosynthesis enabled us to decrease the effective doses by 5-fold as compared to CT acquisition.•CT acquisitions could be avoided when the findings of primary tomosynthesis for sacroiliitis suspicion are negative.