Baraliakos X, Richter A, Feldmann D, et al. - MRIs of 793 individuals aged < 45 years were assessed in order to examine the frequency of bone marrow edema (BME) and fatty lesions (FL) indicative of axial spondyloarthritis (axSpA) on MRI of the spine and sacroiliac joints (SIJ) in a general population sample. SIJ BME was observed in 136, VC BME in 218 and FL in 645 volunteers. SIJ BME in ≥ 1, ≥ 3 and ≥ 5 SIJ quadrants was noted in 136, seven and one participants, respectively. In VC, BME ≥ 1, ≥ 3 and ≥ 5 lesions were noted in 218, 38 and six volunteers, whilst FL≥ 1, ≥ 3 and ≥ 5 in 645, 351 and 185, respectively. Logistic regression analysis revealed that BME and FL in VC were associated with progressing age. In conclusion, in this large population-based study, a high frequency of inflammatory and fatty MRI lesions indicative of axSpA was discovered, particularly in the spine. This intimates a limited value of such MRI findings for diagnosis and classification of axSpA. Moreover, the growing number with age implies that mechanical factors could play a part.