EFFECTIVE DOSE AND RISK ASSESSMENT FROM COMPUTED-TOMOGRAPHY OF THE MAXILLOFACIAL COMPLEX

The effective dose from computed tomography of the maxillofacial compl ex has been estimated and used for an assessment of risk. For each sca n sequence 64 TLDs were placed in 27 selected sites in the upper porti on of a tissue-equivalent human phantom to record the equivalent dose in radiosensitive organs/tissues. Equivalent doses ranged from 0.11 mS v (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 sliceces of the ma xilla were found to result in an effective dose of 0.1 mSv, and four c ontiguous 1 cm axial slices of the mandible in an effective dose of 0. 76 mSv. Effective doses of this magnitude represent a probability of s tochastic effects of the order of 8 x 10(-6) and 56 x 10(-6) respectiv ely.