Eye lens dose for medical staff assisting patients during computed tomography: comparison of several types of radioprotective glasses

Medical staff sometimes assists patients in the examination room during computed tomography (CT) scans for several purposes. This study aimed to investigate the dose reduction effects of four radioprotective glasses with different lead equivalents and lens shapes. A medical staff phantom was positioned assuming body movement restraint of the patient during chest CT, and H_p(3) at the eye surfaces of the medical staff phantom and inside the lens of the four types of radioprotective glasses were measured by changing the distance of the staff phantom from the gantry, eye height, and width of the nose pad. The H_p(3) at the right eye surface with glasses of 0.50-0.75 mmPb and 0.07 mmPb was approximately 83.5% and 58.0%, respectively, lower than that without radioprotective glasses. The dose reduction rates at left eye surface increased with over-glass type glasses by 14%-28% by increasing the distance from the CT gantry to the staff phantom from 25 to 65 cm. The dose reduction rates at the left eye surface decreased with over-glass type glasses by 26%-31% by increasing the height of the eye lens for the medical staff phantom from 130 to 170 cm. The H_p(3) on the left eye surface decreased by 46.9% with the widest nose pad width compared to the narrowest nose pad width for the glasses with adjustable nose pad width. The radioprotective glasses for staff assisting patients during CT examinations should have a high lead equivalent and no gap around the nose and under the front lens.

Can leaded glasses protect the eye lens in patients undergoing neck computed tomography?

BACKGROUND AND AIMS

Computed tomography (CT) is one of the main sources using ionizing radiation. Considering the toxicity from this radiation, any technique that could reduce the radiosensitive organs' doses without affecting the image diagnostic quality must be considered in routine practice. In this study, the amount of eye lens dose reduction in the presence of radioprotective glasses was evaluated in neck CT examinations.

METHODS

Thirty adult patients (15 men and 15 women) with a mean age of 44.6 years undergoing neck CT examination participated in this study. For each patient, six thermoluminescent dosimeters (TLDs-100) were attached above the eye lens glasses surface, and another six under the glasses to assess the radioprotective effect of the glasses. The TLDs were readout and converted to Hp (3) as an indicator of eye lens dose. The obtained results from the TLD readouts as eye lens dose were compared using a paired t-test.

RESULTS

The TLD measurements showed the mean±standard deviation values of 2.97±0.61 mGy and 1.04±0.16 mGy for TLDs above and under the radioprotective glasses, respectively. The radioprotective glasses significantly decreased the eye lens dose by about 64.9% (P=0.001).

CONCLUSIONS

Due to the results, wearing radioprotective glasses for patients during neck CT scans could significantly reduce the eye lens doses.

RELEVANCE FOR PATIENTS

The outcome of this research shows that leaded glasses can decrease the received dose significantly in patient during neck CT scans.