Dose optimization by altering the operating potential and tube current exposure time product in dental cone beam CT: a systematic review

Abstract

Objectives: Current guidelines highlight the need to optimize exposure parameters on CBCT equipment to levels that are as low as diagnostically acceptable. This systematic review aimed to answer the question "Can altering operating potential (kV) and tube current exposure time product (mAs) on CBCT machines reduce radiation dose to patients undergoing dental and/ or maxillofacial scans without a detrimental impact on image quality/diagnostic accuracy?" Methods: Studies were selected and results reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. For each individual study, two authors (RG and JD or KH) independently extracted data using a specifically designed collection form, and an overall quality value was assigned using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Any disagreements in the overall quality value of a study were resolved by discussion between the current authors. Results: Nearly 75% of studies were considered to be of low or very low methodological quality using the GRADE system, and more studies stated that their results applied only in the specific situations they had investigated. However, most studies demonstrated that patient dose reduction is possible without a clinically relevant reduction in image quality. Conclusions: For many CBCT machines, it should be possible to optimize one, or more, of the investigated exposure parameters and therefore reduce patient radiation dose, while maintaining diagnostic image quality for some diagnostic tasks. However, more rigorous research is still required.

Analysis of the priority of anatomic structures according to the diagnostic task in cone-beam computed tomographic images

“…These results support the proposal that by reducing tube current, it is possible to reduce radiation dosage without image quality degradation for implant planning. These results are in agreement with those of previous studies 21314. However, reducing the tube current deteriorated the image quality for periapical diagnosis.…”

“…Many studies have been conducted on CBCT image quality, but insufficient information has been published on the assessment of the relationship between image quality and the visibility of anatomic structures corresponding to specific diagnostic tasks 2. Only 3 studies have evaluated 2 or more diagnostic tasks 3911.…”

“…Image quality can also be assessed by the subjective evaluation and quantitative measurement of physical factors 2. Many studies have investigated the technical image quality parameters of CBCT devices, but they used different phantoms, CBCT scanners, exposure parameters, and diagnostic tasks 345678.…”

“…Standardization of subjective evaluation is difficult due to its subjectivity and differences in the methodologies of previous studies 391011. Subjective evaluations usually involve the identification of anatomic structures by a radiologist 2391011. Many anatomic structures are present in the maxillofacial region, and the importance of specific landmarks may differ according to the diagnostic task 91112.…”

Optimization of cone beam computed tomography image quality in implant dentistry

“…In light of the concerns about radiation dose from CBCT imaging, dose optimization studies have been reported, with a couple of recent review articles summarizing previous studies nicely (Goulston, Davies, Horner, & Murphy, ; McGuigan, Duncan, & Horner, ). In a systematic review, the need for consistent test objects, methodologies, and reporting of techniques was identified for better comparison between studies; despite these shortcomings, the authors concluded that CBCT dose reduction should be possible without compromising the diagnostic quality, at least for some imaging tasks (Goulston et al, ). McGuigan et al () concluded that optimization of kV and mA is challenging to balance the image quality with radiation dose and noted a need to relate the objective metrics of image quality to clinical tasks and radiation dose.…”