The Added Value of Quantitative DWI MRI in Differentiation between Benign and Malignant Osseous Musculoskeletal Tumours

Abstract Background: MRI has a key role in identification of MSK masses, especially in depiction of their nature, borders, regional involvement and their relation to the surrounding organs and neurovascular bundle. MRI aids clinicians in assessment of osseous tumors to depict the extra-osseous component, and the regional location as well, since both parameters are crucial for the pre-operative assessment. Aim of Study: To evaluate the role of Diffusion Weighted Imaging (DWI) in differentiation of benign and malignant osseus musculoskeletal (MSK) tumors and its added value clinically on patient's management. Patients and Methods: The study included 100 patients; 65 males (65%), and 35 females (35%). Their ages ranged from 3 to 69 years with mean age about 31 years. Patients were selected based on clinical and X-ray image suspicion of MSK tumors. Signal intensity of the lesion on DWI was determined and Attenuation Diffusion Coefficient (ADC) map was measured. The Region of Interest (ROI) for each lesion was placed at least 3 times, and then the mean ADC value for the lesion was calculated. Histopathological findings and clinical follow-up were used as standard of reference. Results: Twenty one 21 (21%) patients had benign tumors, 73 (73%) patients had malignant tumors and 6 (13.6%) patients had tumor like lesion. The cut-off value for mean ADC was <1 X 10–3mm2/sec. The gold standard of this study was the histopathological correlation and the imaging-clinical correl-ative features for the benign lesions. Conclusion: DWI MRI technique that is easily included in a routine MR study with short scanning time offering valuable data about the cellularity of a MSK lesion and properly differentiating benign and malignant lesions.