Effective dose from cone beam CT examinations in dentistry

TLDR

Cone‑beam CT is increasingly used in UK dental practice, yet patient dose information across its various fields of view remains sparse. This study aimed to quantify the effective dose delivered to patients during common dental CBCT examinations. Effective doses were calculated from scans of a Rando phantom with thermoluminescent dosemeters on an i‑CAT CBCT system, applying 1990 and 2007 ICRP tissue‑weighting factors. Measured doses ranged from 9.7 µSv to 206.2 µSv, showing CBCT doses are lower than conventional CT but higher than standard dental radiography.

Abstract

Cone beam CT (CBCT) is becoming an increasingly utilized imaging modality for dental examinations in the UK. Previous studies have presented little information on patient dose for the range of fields of view (FOVs) that can be utilized. The purpose of the study was therefore to calculate the effective dose delivered to the patient during a selection of CBCT examinations performed in dentistry. In particular, the i-CAT CBCT scanner was investigated for several imaging protocols commonly used in clinical practice. A Rando phantom containing thermoluminescent dosemeters was scanned. Using both the 1990 and recently approved 2007 International Commission on Radiological Protection recommended tissue weighting factors, effective doses were calculated. The doses (E(1990), E(2007)) were: full FOV head (92.8 microSv, 206.2 microSv); 13 cm scan of the jaws (39.5 microSv, 133.9 microSv); 6 cm high-resolution mandible (47.2 microSv, 188.5 microSv); 6 cm high-resolution maxilla (18.5 microSv, 93.3 microSv); 6 cm standard mandible (23.9 microSv, 96.2 microSv); and 6 cm standard maxilla (9.7 microSv, 58.9 microSv). The doses from CBCT are low compared with conventional CT but significantly higher than conventional dental radiography techniques.