CBCT Voxel
Pronunciation: VOK-sel
The smallest three-dimensional unit of data in a cone beam computed tomography volume, analogous to a pixel in two-dimensional imaging, with dimensions that determine the spatial resolution of the reconstructed image.
Full Definition
A voxel (volumetric pixel) in CBCT is an isotropic or near-isotropic cubic element of the reconstructed 3-D dataset, with edge lengths typically ranging from 0.075 mm to 0.4 mm depending on the machine and selected field of view. Smaller voxel sizes yield higher spatial resolution and finer detail but generally require higher radiation dose and longer reconstruction times. Editors of CBCT reports must ensure that voxel size is reported with its unit (mm or µm) and not confused with image resolution expressed in line pairs per millimetre. The voxel size selected should be justified in relation to the diagnostic task in accordance with the ALARA principle.
Usage
Usage note: Always accompany voxel size with its unit (e.g., 0.2 mm voxel). Do not equate voxel size directly with spatial resolution; resolution is influenced by additional factors including detector characteristics and reconstruction algorithms.
In Context
- "A voxel size of 0.125 mm was selected to allow detection of fine root fracture lines in the CBCT volume." — CBCT acquisition protocol
- "The report incorrectly stated the voxel size in pixels rather than millimetres; this was corrected during editorial review." — Radiology report quality check