Effects of tube current on cone-beam computerized tomography image quality for presurgical implant planning in vitro.

Objective: The purpose of this study was to evaluate the effect of tube current reduction on the quality of cone-beam computerized tomography (CBCT) images of the maxilla and mandible for presurgical implant planning.

Study Design: Six cadaver heads were imaged with a CBCT (3D Accuitomo) operated at 80 kVp and variable tube current (8, 4, 2, or 1 mA) in full-scan mode. For the posterior region of maxilla and mandible, half-scans were also performed at similar settings. The images were evaluated independently by 5 oral radiologists for 15 anatomic landmarks regarding presurgical implant planning. The quality of images were compared with their respective reference images at 8 mA and ranked on a 4-point rating scale as excellent, good, fair, or nondiagnostic. The scores of all observers were averaged for each landmark at every exposure condition, and Bonferroni test (P<.05) was performed.

Results: The 4 mA images at full-scan mode could visualize each landmark of maxilla and mandible and were evaluated to be the same or almost equivalent in quality as the 8 mA images. Even 2 mA images in full-scan mode and 4 mA in half-scan mode could be used for implant planning. The 1 mA images were unacceptable owing to the substantial degradation in image quality.

Conclusion: Significant dose reduction can be achieved by reducing tube current without substantial loss of image quality for presurgical implant planning in CBCT.