This article outlines the substantial reduction in radiation exposure to body parts which are shielded during a CT scan but not included in the field of imaging.
That is a very good practice.
More controversial is another practice: shielding sensitive body parts which ARE included in the field of imaging, specifically breasts, thyroid and gonads.
For some types of scanners this works well, while for other types less well.
With our scanners (GE) IF shielding to the sensitive body part is applied after the scout views are obtained, and IF the shield is separated from the body by placing towels or a blanket to elevate the shield off the body by 2-3 cm – then this works well. Any artifacts or other issues with image quality are minimal or out of the area of interest and the dose to the shielded body part does drop measurably.
Further, such shielding sends a strong message to patients and to our own staff about our concern for their safety.