Pediatric dental cone-beam computed tomography using half-acquisition and low-noise reconstruction: visual evaluation of clinical images

This study evaluated whether half-acquisition (180° scan) pediatric cone-beam computed tomography (CBCT; 3D Accuitomo F17, J. Morita, Kyoto, Japan) reduces radiation exposure while maintaining sufficient diagnostic image quality for identifying ectopic eruptions and impacted teeth. Additionally, it was investigated whether a low-noise reconstruction filter (G_101) mitigates image quality degradation in 180° scans. Three board-certified oral and maxillofacial radiologists certified by the Japanese Society for Oral and Maxillofacial Radiology visually evaluated clinical images from 12 pediatric patients (aged 6-10 years). The image quality was objectively assessed using phantom-based analyses of the modulation transfer function (MTF), noise power spectrum (NPS), and comprehensive objective image quality calculated from MTF and NPS values. Although 180° images showed increased noise and slightly lower visual assessment scores compared with 360° images, they remained diagnostically acceptable. In 180° reconstructions, the median visual scores with the G_101 filter were slightly higher than those with the standard G_001 filter, with small differences (within approximately 0-3 points on a 100-point scale), although the differences were not statistically significant. Interestingly, in approximately 28% of 180 evaluations, 180° images scored higher than 360° images, likely due to reduced motion artefacts from shorter acquisition. In a previous phantom experiment, the dose area product (DAP) for 360° and 180° scans was 490 mGy cm² and 249 mGy cm², respectively, indicating that 180° scan reduces radiation exposure while maintaining clinically acceptable image quality. These findings suggest that half-acquisition, when combined with an appropriate reconstruction filter, may offer a practical, low-dose alternative for pediatric dental imaging.