The MRI sequences demonstrate an expansile multiloculated lesion involving almost the entire femoral diaphysis with multiple fluid-fluid levels seen within the medullary cavity as well as the medial subperiosteal component with multiple areas of cortical destruction.
It shows a low signal on T1WI with multiple haemorrhagic areas of high signal, heterogeneous high signal on T2WI, and STIR with enhancement of septa as well as the periosseous soft tissue component. Oedematous infiltration of the adjacent muscles is noted.
There is a small enhancing lesion of the medial aspect of the right distal femoral metaphysis well-visualized mainly on coronal sequences, not well-visualized on diffusion sequence which normally should be performed in the coronal plane (non-specific lesion).