A cloud-fog software architecture for dental CBCT dose monitoring using the DICOM structured report: Automated establishment of DRL

Proposed Diagnostic Reference Levels in the Missouri/Southern Illinois Region Associated with Cone-beam Computed Tomography Use in Endodontics

INTRODUCTION

Diagnostic reference levels (DRLs) are intended to improve patient safety and ensure that patient ionizing radiation doses are as low as reasonably achievable. The purpose of this dosimetry study was to establish regional DRL levels for cone-beam computed tomography (CBCT) imaging for specialty endodontics. Another aim was to compare phantom-measured ionizing radiation dose index 1 (DI1) index doses to the manufacturer-provided dose area product (DAP) radiation output values for each of the CBCT machines studied, to ascertain their degree of correlation. DAP refers to the dose area product, a measure of radiation dose monitoring which represents the dose within the beam times the area within the beam at that position.

METHODS

A thimble ionization chamber and polymethyl methacrylate phantom were used to obtain DI1 values using the SEDENTEXTCT method from 21 different CBCT units. DRLs were calculated based on the 75th percentile (third quartile) of the median output values.

RESULTS

The proposed DRL from the CBCT units surveyed has a DAP value of 838 mGy cm2 and a DI1 value of 3.924 mGy. DAP versus DI1 values of 500.6 mGy cm2 versus 2.006 mGy, and 838 mGy cm2 versus 3.906 mGy represented the third quartile of the median values for the 4-cm × 4-cm and 5-cm × 5-cm field of views (FOVs), respectively.

CONCLUSIONS

The DI1 and DAP values strongly correlated when 3 outlier CBCT machines (J Morita Veraview X800) using a novel 360° (full rotation) acquisition mode were excluded. The importance of selectable exposure parameters as directly related to ionizing radiation output is illustrated among the CBCT units surveyed. Although the actual FOV that is selected is ultimately dictated by the specific clinical requirements, a 4-cm × 4-cm FOV is recommended for specialist endodontics practice, whenever clinically practical, based on the decreased ionizing radiation output, as compared to that from a 5-cm × 5-cm FOV.

CT doses based on clinical indications. New national DRL's in Iceland

A diagnostic reference level (DRL) is an investigation level to use in the optimization of a medical exposure using ionizing radiation. The aim of this project was to gather dose data from computed tomography (CT) studies in Iceland with the purpose of updating existing national DRL and proposing DRLs based on clinical indications. Dose data (total dose length product (DLP) and CT dose index) were retrospectively collected from all CT scanners in Iceland for 50 patients for all common CT studies. After cleaning the data, the data set contained total DLP for 8129 patients. Considering dose-relevant parameters such as the number of phases and scan length, each CT study was assigned to one of 42 study types and (at least) one clinical indication. Data were received from seven or more scanners for 13 clinical indications and from all scanners providing coronary angiography. There was considerable variation in the median total DLP from different scanners, e.g., from 13 to 139 mGycm for Sinusitis, and, the range of individual total DLPs varied between scanners. This underscores the importance of monitoring patients' exposure. The study shows that there is room for optimization. New Icelandic NDRLs were proposed for the total DLP of CT examinations based on ten different indications, including: Brain ischemia (1060 mGycm), Interstitial lung disease (310 mGycm) and Appendicitis (690 mGycm). The proposed NDRLs were the first clinical indication based NDRLs in Iceland. The Icelandic Radiation Safety Authority has decided to update the NDRLs based on the results of this study.