Effective dose and risk assessment from computed tomography of the maxillofacial complex.

The effective dose from computed tomography of the maxillofacial complex has been estimated and used for an assessment of risk. For each scan sequence 64 TLDs were placed in 27 selected sites in the upper portion of a tissue-equivalent human phantom to record the equivalent dose in radiosensitive organs/tissues. Equivalent doses ranged from 0.11 mSv (bone marrow, maxillary scan) to 20 mSv (salivary glands, mandibular scan). By the use of a calculation that included the salivary glands as part of the remainder, two contiguous 1 cm axial slices of the maxilla were found to result in an effective dose of 0.1 mSv, and four contiguous 1 cm axial slices of the mandible in an effective dose of 0.76 mSv. Effective doses of this magnitude represent a probability of stochastic effects of the order of 8 X 10(-6) and 56 X 10(-6) respectively.