Information regarding linear accuracy is necessary for efficient treatment evaluation, especially for maxillofacial reconstruction or implants.Purpose:
To investigate the accuracy of linear measurements from multiple cone beam computed tomography (CBCT) devices.Materials and Methods:
A RANDO® phantom was scanned with eight CBCT scanners (11 modes). The viewing software accompanying each scanner was employed for measurements in mediolateral, anteroposterior, and supero-inferior dimensions by two dentomaxillofacial radiologists. Digital caliper measurements were used as a “gold standard.” ANOVA with Scheffé post hoc analysis and intraclass correlation coefficient (ICC) were utilized for statistical analyses. The level of confidence was 95%.Results:
Differences from the gold standard among 11 acquisition modes were statistically significant (p < .001). Measurements from one unit were always underestimated compared with all others (p < .001). The range of absolute measurement errors for tested units was −2.56 to 0.54 mm (mean ± SD 0.45 ± 0.71) including the outlier and −0.34 to 0.54 mm (0.16 ± 0.11) excluding the outlier. Slightly more values were underestimated than overestimated (41 of 66 measurements, 7 out of 11 CBCT modes). ICC scores for inter- and intraobserver agreement were perfect (1.000).Conclusions:
Treatment planning from large-volume CBCT was found to be reliable in all except one of the investigated scanners. New CBCT scanners should always be tested for geometric accuracy.