How accurate is MRI in prediction of musculoskeletal tumors -A prospective evaluation

Abstract

Background: To determine the accuracy of MRI in determining the characteristics of musculoskeletal tumors, [including both skeletal (primary/secondary) and soft tissue tumors] and correlation of MRI findings with histopathological study. Methods: 50 consecutive patients referred to the department of radiodiagnosis, of Assam Medical College, Dibrugarh, were included in this study. MRI was performed on 1.5 Tesla superconducting system (MAGNETOM Avanto, Siemens). After localizer sequences, T1W T2W, and STIR images, Fat saturated and post contrast T1W, images were obtained in sagittal, coronal planes, axial planes. Additional sequences like dynamic angiography and spectroscopy were taken when required and when feasible, especially in soft tissue tumors. Results: Features that indicated benignity of soft tissue tumors (under musculo skeletal tumors) are size ( than 6 cm), homogeneity in T2 signal, absence of oedema, necrosis, haemorrhage, fascial penetration, bone changes. Presence of abnormal blood vessels in dynamic angiography, presence of choline peak in spectroscopy was clue to malignancy. A correct histological diagnosis is reached on the basis of imaging studies alone is 66 % of cases. The sensitivity for a MRI diagnosis of bone and soft tissue tumour was 100 % and accuracy was 98 %. Specificity of detecting benignity and malignancy is 94.7%. Conclusion: Diagnosis of musculoskeletal tumors is best made by a combination of clinical and plain picture imaging parameters rather than by any single MR characteristic, except lipomas. When a lesion has a non-specific MR imaging appearance, it is useful to formulate a suitably ordered differential diagnosis based on tumour prevalence, age.