SUVmaxis preferred over SUVavg as there is a variability of about 35% between observers when SUVavg is used and this reduces to 3% when SUVmax is used[6].The SUVmax cutoff value of 2.5 is used commonly to differentiate between benign and malignant lesions[7].Kumar's study about 35 cases of mediastinal lymphadenopathy diseases showed that appropriately increasing the cut off values can improve the specificity, while maintaining an acceptable sensitivity[8]. When 2.5 or 6.2 was used as the cutoff value, the sensitivity, specificity, positive predictive value(PPV), negative predictive value (NPV), and accuracy were 93%, 40%, 54%, 89%, 63% and 87%, 70%, 68%, 87%, 77%, respectively[8]. However it has been shown that there is a significant number of false positivity (due to inflammatory diseases) and false negativity (due to low-grade
SUVmaxis preferred over SUVavg as there is a variability of about 35% between observers when SUVavg is used and this reduces to 3% when SUVmax is used[6].The SUVmax cutoff value of 2.5 is used commonly to differentiate between benign and malignant lesions[7].Kumar's study about 35 cases of mediastinal lymphadenopathy diseases showed that appropriately increasing the cut off values can improve the specificity, while maintaining an acceptable sensitivity[8]. When 2.5 or 6.2 was used as the cutoff value, the sensitivity, specificity, positive predictive value(PPV), negative predictive value (NPV), and accuracy were 93%, 40%, 54%, 89%, 63% and 87%, 70%, 68%, 87%, 77%, respectively[8]. However it has been shown that there is a significant number of false positivity (due to inflammatory diseases) and false negativity (due to low-grade