Absence of radiometric differentiation between periapical cysts and granulomas.

A recent study reported that the mean density of periapical cysts was greater than that of periapical granulomas. This study, which used a larger sample size and a robust method for standardization of density and contrast between images, found no difference between the radiographic density of cysts and granulomas classified by microscopic evaluation. Cysts tend to be larger than granulomas, but there was wide variation in size of both types of lesions. There was no significant correlation between the density of a lesion and its size.