Usefulness of Diffusion Weighted MRI in Differentiating Benign from Malignant Bone Lesions

Abstract

Background Bone tumors represent a wide spectrum of disease in children & adult ranging from benign lesions to an aggressive malignancy, so finding a noninvasive diagnostic tool was needed. Objective We aimed to differentiate between benign and malignant bone lesions and to limits the number of patient with benign lesion who undergo biopsy. Patients and Methods Our study was carried out on 32 patients were diagnosed with bone tumors (21 benign & 11 malignant), at the MRI unit of the Radiology Department Ain Shams University, outpatient clinics and private centers after getting approval from each ethical committee. They were assessed with conventional & diffusion MR images, DW EPI carried out using different b values including 0 s/ mm², 500 s/ mm², and 800 s/ mm². ADC map were automatically calculated. Results The mean ADC value for benign tumors was 1.6±0.4 x 10 -3 mm2/s. while malignant tumors were 1.2±0.3 x 10 -3 mm2/s. ROC analysis was used to define the best cut off mean ADC value for detecting malignancy which was <1.3, with sensitivity of 81.8% specificity of 81%. Conclusion The present study showed high specificity and sensitivity of DWI as a complementary sequence with conventional MRI and ADC value measurements in discrimination between benign and malignant bone tumors with significant cut-off value, making it a noninvasive tool for increasing the accuracy in identifying bone lesions.