Résumé
Background: Functional magnetic resonance imaging [MRI] improves tissue characterization and staging of bone tumors compared to the information usually supplied by structural imaging. Dynamic MRI and diffusion MRI can be performed in everyday practice. Tumour characterization can benefit from perfusion MRI with dynamic gadolinium injection and enhancement time-intensity curve analysis combined with quantitative and qualitative diffusion MRI
Aim of the Work: is to elucidate the role of advanced MRI techniques in diagnosis of pediatric bone tumors and to assess the diagnostic potential of Dynamic contrast enhancement [DCE] in conjunction with Diffusion weighted imaging [DWI] in differentiating benign from malignant bone tumors
Patients and Methods: a prospective study conducted on thirty pediatric patients with clinically suspected and radiologically proven bone tumor or tumor like lesion. The patients were referred from the Department of Orthopedics, Ain Shams University. The patients were investigated using 1.5 Tesla magnetic resonance device. They were subjected to conventional MRI and DCMI
Results: DWI with measurement of Apparent diffusion coefficient [ADC] values helped in the differentiation of benign and malignant bone tumors, and that the best cut-off criterion is ADC of 0.9 is defined as benign results with overall sensitivity 100% and specificity 100%. A type II curve was seen in 23 cases [one malignant and twenty two benign], type IV was seen in 5 cases [all are malignant] and type V curve was seen in two malignant cases [after chemotherapeutic treatment]. ROC analysis for the Dynamic contrast enhancement [DCE] showed a sensitivity of 75 % and specificity of 100%
Conclusion: DWI and DCE-MRI had been proven to be highly useful in the differentiation of benign and malignant bone tumors. Measurement of ADC values improved the accuracy of the diagnosis of bone tumors. Moreover; they could be used in the follow up of tumors and their response to therapy