[Circumscribed myositis ossificans: bone changes detected by MRI].

The authors report a case of ossificans myositis, in which MRI showed inflammatory changes of the adjacent bone. T1 weighted fat saturation sequence with gadolinium injection showed enhancement of medullary and cortical bone. This potentially mistaking pattern must be known, to avoid misdiagnosing with malignant osseous tumor, specially before achievement of the characteristic pattern of zonal maturation and its calcified rim.

[Dental-radicular cysts invading the maxillary sinus].

The authors report three cases of radicular cyst developing into the maxillary sinus which was partially or completely obscured. Looking for a thin rim of cortical bone should be undertaken in case of opacity of maxillary sinus. This rim correspond to the floor of the sinus, which is lifted up by the cyst.

[Rhabdomyolysis and truncular sciatica. 2 cases studied by MRI].

We report two cases of acute rhabdomyolysis in pelvic girdle muscles with sciatic palsy secondary to compression of the sciatic nerve trunk, with clinical and MRI correlation. The diagnosis of rhabdomyolysis is based on clinical and biological data, but diagnosis of compression complications secondary to swelling of the muscles, especially the compression of nerve trunk, is done by imaging. T2 weighted images give a definite anatomical evaluation.