IMAGING OF OSTEOSCLEROTIC METASTASES

Carcinomas of the prostate and breast are the most common sources of o steosclerotic metastases. The osteoblastic response is related to stro mal bone formation and reactive bone formation. Purely osteosclerotic or mixed osteolytic-osteosclerotic lesions are encountered. Frequent d ifferential diagnoses are enostoses and Paget's disease. The classical MRI pattern is a signal of low intensity on T1 and T2- weighted seque nces, but some osteoblastic metastases have an inhomogenous signal. Ev aluation of the response to treatment is difficult and requires confro ntation with clinical and biological data.