Abstract: The ¹⁸F-FDG PET has been used extensively in the diagnosis and staging of several types of malignancies. In general, standardized uptake values (SUV)in single time point imaging has been used for separating malignant from benign lesions, nevertheless there is considerable overlap be, tween SUV of them, thereby limiting specificity of this method. According to various cell types exhibit varying rates of ¹⁸F-FDG uptake, performing dual time point imaging (scan 1 and scan 2)appears to be useful in differentiating malignant from benign lesions. This protocol is a simple and practical method with high sensitivity, high specificity and good accuracy for detection of malignant lesions.