What is the main role of MRI in this instance?
It primarily establishes the local extent of disease (extraosseous component, involvement of adjacent neurovascular structures etc..).
An expansile multilobulated intramedullary, T1 hypointense, heterogeneous T2 hyperintense enhancing lesion extends from the medial aspect of the clavicle to involve the shaft for a length of approximately 7 cm. The lesion is expansile with evidence of cortical erosion and cortical breach with a small ( 6mm) soft tissue component protrudes through the posterior cortex of the clavicle. No convincing periosteal reaction. There is a wide zone of transition along the lateral aspect of the lesion. No extension into the manubriosternal articulation. No encasement of the adjacent subclavian vessels.