Effective doses from cone beam CT investigation of the jaws

Objectives: The purpose of the study was to calculate the effective dose delivered to the patient undergoing cone beam (CB) CT of the jaws and maxillofacial complex using the i-CAT Next Generation CBCT scanner (Imaging Sciences International, Hatfield, PA). Methods: A RANDO (R) phantom (The Phantom Laboratory, Salem, NY) containing thermoluminence dosemeters were scanned 10 times for each of the 6 imaging protocols. Effective doses for each protocol were calculated using the 1990 and approved 2007 International Commission on Radiological Protection (ICRP) recommended tissue weighting factors (E1990, E2007). Results: The effective dose for E1990 and E2007, respectively, were: full field of view (FOV) of the head, 47 mSv and 78 mSv; 13 cm scan of the jaws, 44 mSv and 77 mSv; 6 cm standard mandible, 35 mSv and 58 mSv; 6 cm high resolution mandible, 69 mSv and 113 mSv; 6 cm standard maxilla, 18 mSv and 32 mSv; and 6 cm high resolution maxilla, 35 mSv and 60 mSv. Conclusions: Using the new generation of CBCT scanner, the effective dose is lower than the original generation machine for a similar FOV using the ICRP 2007 tissue weighting factors. Dentomaxillofacial Radiology (2012) 41, 30-36. doi: 10.1259/dmfr/3017790