Introduction and purpose: We present a new decision-making method to assist orthopaedists and radiologists in diagnosing soft-tissue tumours. It can distinguish between benign and malignant characteristics in these lesions and classify them histologically with satisfactory efficiency. The pre-surgical diagnosis of the nature of the tumour and whether it is benign or malignant is crucial to planning surgical procedures.

Materials and methods: We reviewed our cases of soft-tissue tumours (47) studied by MRI over the past year and a half. They are part of a multicentre study involving several European hospitals (430 patients).

We analysed the clinical and MRI data: age, clinical presentation, size, shape, location, edges, image signal, calcification, intratumour fat, dependency, fibrosis, relation to fascias, bone and vessel disorders.

Results: With this method we detected 62% benign tumours and 38% malignant. The system sensitivity and specificity are 86% and 95%, respectively.

Conclusions: It is easy to distinguish between vascular, nerve and cystic lesions. The diagnosis of fibrous, synovial and fatty lesions is complex in all cases.

The method can help orthopaedists make a diagnosis before surgery, which will facilitate planning of surgical procedures.