Effect of Voxel Size on the Accuracy of Airway Volumetric Measurements Using Cone Beam Computed Tomography

Abstract

Aim: The purpose of this retrospective study was to evaluate the accuracy and reliability of the airway volume, dental, and skeletal parameters measured digitally on cone beam computed tomography scans (CBCTs) using airway model scanned with different resolutions.

Material and method: This retrospective study was performed using CBCT images obtained from an artificial model of airway made by an acrylic airway model scanned at different voxel sizes, timing, and segmentation levels. CBCT scans were divided into four groups according to the voxel size of each scan (0.2, 0.25, 0.3 and 0.4). Airway volume parameters were measured using Dolphin 3D (Dolphin Imaging & Management solutions, Chatsworth, California, USA) software version 11.95. Reliability and accuracy were assessed by using intraclass correlation and Student’s t-test. A P-value of less than 0.05 was considered significant.

Results: The intra- and inter-examiner reliability were high for all measurements. Significant statistical differences were detected among airway volume measured at variable voxel size, scanning time, and segmentation level however, no significant differences were found in the skeletal and dental parameters. These results suggested that the airway measurements vary according to the voxel size, scanning time and segmentation level.

Conclusion: Airway volume measurements vary depending on the voxel size, scanning time and segmentation level of CBCT scans. Clinicians and researchers should be aware of the effect of the voxel size and scanning resolution on the airway measurements since this could affect the clinical judgement of critical cases.