Halve the dose while maintaining image quality in paediatric Cone Beam CT

Abstract

Cone beam CT (CBCT) for dentomaxillofacial paediatric assessment has been widely used despite the uncertainties of the risks of the low-dose radiation exposures. The aim of this work was to investigate the clinical performance of different CBCT acquisition protocols towards the optimization of paediatric exposures. Custom-made anthropomorphic phantoms were scanned using a CBCT unit in six protocols. CT slices were blinded, randomized and presented to three observers, who scored the image quality using a 4-point scale along with their level of confidence. Sharpness level was also measured using a test object containing an air/PMMA e,dge. The effective dose was calculated by means of a customized Monte Carlo (MC) framework using previously validated paediatric voxels models. The results have shown that the protocols set with smaller voxel size (180 µm), even when decreasing exposure parameters (kVp and mAs), showed high image quality scores and increased sharpness. The MC analysis showed a gradual decrease in effective dose when exposures parameters were reduced, with an emphasis on an average reduction of 45% for the protocol that combined 70 kVp, 16 mAs and 180 µm voxel size. In contrast, both “ultra-low dose” protocols that combined a larger voxel size (400 µm) with lower mAs (7.4 mAs) demonstrated the lowest scores with high levels of confidence unsuitable for an anatomical approach. In conclusion, a significant decrease in the effective dose can be achieved while maintaining the image quality required for paediatric CBCT.

In vivo detection of external apical root resorption induced by apical periodontitis using periapical radiography and cone-beam computed tomography

“…In cases of impacted and supplementary teeth, dentoalveolar trauma, orofacial defects dental anomalies and bone pathologies, where there is a justi ed reason for CBCT prescription, effective dose should be managed (21). Reduction of radiation risk could be achieved by managing X-Ray tube voltage and current (22), exposure time, FOV, number of projections and patient's shielding devices (19). Considering that the amount of radiation is directly related to the period of image taken and the eld of the vision (FOV) (23), diagnostic modalities with smaller eld are currently used.…”

Paradigma baru konsep proteksi radiasi dalam pemeriksaan radiologi kedokteran gigi: dari ALARA menjadi ALADAIP

“…Pada penelitiannya di tahun 2019, DIMITRA membuktikan bahwa terdapat kemungkinan untuk mengurangi dosis efektif yang selama ini telah digunakan pada pesawat CBCT hingga ke tingkat tertentu dengan tetap memenuhi kualitas radiograf yang baik dan dapat diinterpretasi. 39 Perlu diingat bahwa DIMITRA sampai saat ini hanya berfokus pada pasien pediatri sehingga pengembangan lebih luas terhadap berbagai karakteristik pasien dewasa, lansia ataupun berkebutuhan khusus dapat menjadi rencana penelitian jangka panjang selanjutnya.…”

Cone-Beam Computed Tomography in Orthodontics

“…In addition, reducing the scan time, number of projections, and the mAs (Milliampere-seconds) has an additional role in reducing the dose as well [30,31]. In fact, small and strategic adjustments in exposure parameters can result in significant reduction in the effective dose without significantly compromising the image quality [32,33]. However, significant modifications of these parameters aimed at significant reduction of the effective dose can reduce the image quality [28,34].…”