A review of imaging practice in bone and soft tissue lesions

Thirty six consecutive bone and soft tissue lesions which were referred to the Bone Transplantation Service between January 1987 and June 1989 were reviewed with respect to the information provided by pre-operative CT, MR and plain X-ray and the final histopathologic diagnosis. The ability of CT and MR to demonstrate cortical destruction, periosteal reaction, a soft tissue mass and soft tissue calcification was scored on a scale of one (low suspicion of abnormality) to four (definite abnormality) in each case. Of the thirty six cases reviewed there were twenty-two histologically confirmed tumours with all of the above three imaging modalities available for comparison. In each of these tumours MR was found to provide an equal or more accurate assessment of soft tissue extent. On a scale of 1 to 4 the average point scores were 3.6 and 2.6 for MR and CT respectively. Little difference was shown between CT and MR with respect to medullary involvement (4.0 points vs. 3.9) and cortical destruction (2.5 points vs. 2.7). CT (3.7 points) was more sensitive than MR (1.2 points) in detecting fine soft tissue calcification. In only five cases did the radiology report correctly nominate the histologic diagnosis and thus the role of imaging was more valuable in staging than diagnosis. For this reason a management oriented report should include comment regarding cortical destruction, the intramedullary extent of tumour and the extent of soft tissue involvement. MR is recommended in the investigation of all suspected malignant soft tissue or bone tumours.