Optimization of cone beam computed tomography image quality in implant dentistry

Abstract

This study was conducted to optimize the cone beam computed tomography image quality in implant dentistry using both clinical and quantitative image quality evaluation with measurement of the radiation dose. A natural bone human skull phantom and an image quality phantom were used to evaluate the images produced after changing the exposure parameters (kVp and mA). A 10 × 5 cm2 field of view was selected for average adult. Five scans were taken with varying kVp (70–90 kVp) first at fixed 4 mA. After assessment of the scans and selecting the best kVp, nine scans were taken with 2–12 mA, and the kVp was fixed at the optimal value. A clinical assessment of the implant‐related anatomical landmarks was done in random order by two blinded examiners. Quantitative image quality was assessed for noise/uniformity, artifact added value, contrast‐to‐noise ratio, spatial resolution, and geometrical distortion. A dosimetry index phantom and thimble ion chamber were used to measure the absorbed dose for each scan setting. The anatomical landmarks of the maxilla had good image quality at all kVp settings. To produce good quality images, the mandibular landmarks demanded higher exposure parameters than the maxillary landmarks. The quantitative image quality values were acceptable at all selected exposure settings. Changing the exposure parameters does not necessarily produce higher image quality outcomes but does affect the radiation dose to the patient. The image quality could be optimized for implant treatment planning at lower exposure settings and dose than the default settings.

Cone-beam computed tomography artifacts in the presence of dental implants and associated factors: an integrative review

“…Nine studies were excluded for not meeting the eligibility criteria. Sixteen studies were selected for full-text reading, after which 7 studies were excluded because they dealt with topics related to artifact reduction, the evaluation of peri-implant tissue, and comparisons between the implant radiation dose of CBCT and MSCT, 11 12 13 14 15 16 17 yielding a final total of 9 selected articles. 18 19 20 21 22 23 24 25 26 …”

An investigation into dose optimisation for imaging root canal anatomy using cone beam CT

“…Furthermore, by carrying out the investigations using two commercial CBCT scanners, an analysis of whether the threshold level of objective image quality for this specific diagnostic task could be transferred to a different scanner was carried out. Protocols achieving significant dose reductions for specific dental diagnostic tasks have been established, [11][12][13][14][15] involving dose measurement, objective and subjective assessment, but not in an endodontic context and none of these has investigated the transferability of objective image quality measurements between scanners. Additionally, this study also examined the impact of anatomy complexity on establishing a threshold dose for this diagnostic task and the effect of operator experience on diagnostic efficacy.…”

“…3,9 The pertinence of employing low dose protocols has recently been highlighted, 10 with protocols achieving significant dose reductions suggested in the dental disciplines of paediatric dentistry, 11 orthodontics, 12 tooth autotransplantation (TAT), 13 periodontology 14 and implant dentistry. 15 In the process of optimisation, both the acceptable clinical level of the image quality and the radiation dose may differ according to diagnostic tasks. 16 Although such studies have provided evidence to assist in optimisation efforts for particular scanner models used, there is no evidence that the objective image quality measurements can be transferred to a different manufacturer's CBCT equipment or even to different models from the same manufacturer.…”

“…Because of inter-and intraclinician variability in assessment of radiological images, it is important to relate such subjective assessments to objective measurements of image quality, in this case CNR, with the purpose of identifying if minimally acceptable values exist for specific diagnostic tasks that could potentially aid in the process of dose optimisation. 23 Validated methods of assessing objective and subjective image quality using a SedentexCT phantom and anthropomorphic phantoms respectively have been used in the pursuit of optimizing doses for specific diagnostic tasks 12,14,15 but not for identification of root canal anatomy/imaging for endodontic purposes. As high-resolution protocols are currently recommended for CBCT imaging to assess root canal anatomy, 3 in addition to studying the impact of altering tube voltage and tube current-exposure time product, this study planned to investigate the effect of available scanning protocols including high resolution and 180° scans on achieving this clinical task.…”

Optimization of cone beam computed tomography for the assessment of alterations of the maxillary sinuses

“…The protocols (n = 10) tested in this study were part of a list of pre-established options defined by i-CAT manufacturer. Other studies designed to assess image quality as function of the device setting found out that optimization was feasible by reducing the exposure/dose below the one established by the manufacturer as default (Dawood et al, 2012;Alawaji et al, 2018).…”