Comparison of MR imaging findings in paediatric and adult patients with acute mastoiditis and incidental intramastoid bright signal on T2-weighted images

Objectives To compare MR imaging features in patients with incidental mastoid T2-hyperintensity with those of clinical acute mastoiditis, to ascertain characteristic differences between them. Methods MR images of 35 adult and paediatric patients with clinical acute mastoiditis and 34 consecutive age-matched controls without relevant middle ear pathology and with incidental T2-hyperintensity that covered ≥ 50 % of the mastoid were retrospectively analysed with regard to signal, diffusion, and enhancement characteristics, and presence of complications. Results Incidental mastoid T2-hyperintensity that covered ≥ 50 % of the mastoid volume was found in 4.6 % of reviewed MR scans (n = 2341), and associated significantly ( p