Eye Shielding During Head CT Scans: Dose Reduction and Image Quality Evaluation

Area of Science:

• Radiology
• Medical Imaging
• Radiation Dosimetry

Background:

• Head CT scans involve radiation exposure to sensitive organs like the eyes.
• Eye shields are used to reduce radiation dose to the lens, but can introduce artifacts.
• Tube current modulation (TCM) is a technique to optimize radiation dose and image quality.

Purpose of the Study:

• To assess the radiation dose reduction to the lens using different eye shields.
• To evaluate the impact of eye shields and tube current modulation (TCM) on image quality.
• To compare fixed tube current with topogram-based TCM in head CT examinations with eye shielding.

Main Methods:

• Patients undergoing head CT were assigned to groups with or without eye shields and with fixed or topogram-based TCM.
• Radiation dose to the lens was measured using Gafchromic films.
• Image quality and artifacts were assessed qualitatively by radiologists and quantitatively.

Main Results:

• Barium sulfate and bismuth-antimony shields reduced lens radiation dose by up to 47%.
• Shielding degraded intraocular but not intracranial image quality and induced artifacts.
• Topogram-based TCM improved image quality and reduced artifacts compared to fixed tube current, especially with bismuth-antimony shields.

Conclusions:

• Eye shields effectively reduce lens radiation dose in head CT.
• Topogram-based TCM can mitigate artifacts caused by eye shields, maintaining diagnostic image quality.
• This approach offers an alternative for optimizing CT scans without organ-based TCM.