The effects of voxel size on cone beam computed tomography images of the temporomandibular joints

Abstract

This clinical study assesses the effect of cone beam computed tomography (CBCT) voxel size on the ability to detect osseous changes associated with degenerative disease of the temporomandibular joint (TMJ). The effect of voxel size on perceived CBCT image quality is also evaluated. Twenty-two patients presenting for TMJ imaging with suspected degenerative disease were imaged with the Carestream 9000 CBCT unit, using separate right and left joint acquisitions (n= 44). Images were archived at native and downsampled voxel resolutions of 76 μm and 300 μm, respectively. Three oral and maxillofacial radiologists evaluated the images for osseous changes, as well as image quality by using a visual analog scale. There was no statistically significant difference between the voxel sizes in the detection of TMJ osteoarthritic changes. The mean visual analog scale response did, however, differ significantly between the two groups (P= .02). Despite no improvement in diagnostic efficacy with a smaller voxel size, perceived image quality is consistently higher for images with greater spatial resolution.