Direct radiation exposure of the eye lenses in cranial computed tomography and exposure reduction through...

Ionizing radiation can cause increased opacity of the lens and later lead to radiation-induced cataract. Therefore, the eye lens should be positioned outside of the direct radiation beam in cranial computed tomography (CCT). If this is not possible, protective measures must be taken, which includes the use of external lens protectors. In this study we assess whether direct radiation exposure of the eyes in CCT can be reduced by trained radiographers and whether the use of eye lens protectors improves after training.

First, we evaluated 763 non-enhanced CCT regarding direct radiation exposure of eyeballs and eye lenses and usage of lens shielding. Afterwards, we trained radiographers to avoid radiation exposure of the eyes by head adjustment and protectors and assessed the improvements in a subsequent study of 678 CCT. We tried to identify factors that influenced radiation exposure of the eye lens.

After training, frequency of radiation exposure of lenses was significantly reduced by 5.9% (220/763 patients in pre- vs. 155/678 patients in post-training group, p = 0.01). The use of external lens protectors significantly increased after training by 9.8% (37/763 patients in pre- vs. 99/678 patients in post-training group, p < 0.001). The absence of tiltable headrest was a risk factor for increased eye lens radiation exposure in the pre-training group. The presence of cervical spine immobilizer was associated with more frequent radiation exposure of the lenses in the pre- and post-training group.

Radiographer training and the use of tiltable headrest lead to reduction of radiation exposure to the eye lens.

Radiographer training is an effective method to reduce eye lens exposure in CCT. The usage of tiltable headrest minimizes the radiation exposure of the lenses.