Background: Orbital and intraocular masses are relatively uncommon compared to other mass lesions of the body. It has been described that two-thirds of orbital tumors are benign and one third is malignant. Differentiating between these causes based on clinical findings may be difficult. Some lesions can be diagnosed easily depending on their characteristics on MRI but sometimes their characterization is still difficult. Diffusion weighted imaging (DWI) is an advanced MR-based technique which has the ability to characterize and differentiate morphologic features by measuring differences in apparent diffusion coefficient (ADC) and so can aid in differentiation of malignant and benign orbital lesions, which is focal to planning further patient management.
Aim of the work: Is to investigate the utility of DW-MRI images and generated ADC values in the differentiation between benign and malignant orbital masses.
Patient and Methods: This study included 21 cases (13 females and 8 males) proven to have an orbital mass by an available radiological study.
Results: Of the 21 subjects, 10 out of 11 malignant lesions were correctly classified as malignant (TP) & all of the 10 benign lesions were correctly classified as benign (TN). A sensitivity of 90.9 % was achieved, with a specificity of 100 %. The Positive predictive value was 100 %, while the negative predictive value was 90.9%.
Conclusion: DWI and ADC maps with ADC value calculations are useful for differentiating between malignant and benign orbital tumors. Apparent diffusion coefficient value can solve some clinical problems of the orbit that affect patient management.