Fig. 4
From: Pelvic heterotopic ossification: when CT comes to the aid of MR imaging
Different patterns of HO maturity shown on CT. a Amorphous calcification located within the right quadratus femoris muscle, characterised by ill-defined margins and no recognisable trabecular structure. b Immature ossification located within the right medius gluteus muscle. Lesion shows poorly-defined margins and an initial trabecular formation is recognisable. c Mature ossification located within the left ileopsoas muscle, outlined by cortex with well-defined cancellous bone inside