Radiation exposure to the ocular lens during CT scanning.

Measurements of radiation exposure during routine CT scanning were found to average 4.2 R at the level of the ocular lens. This data was combined with CT scanning rate data from a sample of 100 patients followed in the myelomeningocele clinic. The number of scans averaged 7.75/patient with a range of 0-34 scans. Cumulative radiation exposure to date ranged from 0 to 143 R. Radiation dosage nomenclature and acceptable limits are discussed and recommendations for reduction of dosage are presented.