Items inside the body do not alarm the AIT **. It would be something on the outside of the body (clothes, etc). Many times, the positioning of someone in the machine will help to prevent alarms (match the footprints exactly, heel to toe, and place hands in the exact positon mirroring the image on the glass in front of you). Other than that, I have no more information to give on this one.
**If there is an implant under the skin that causes an appearance that is different than the majority of people (for example a subdermal implant that cause irregularities in the appearance of the skin), it could possibly alarm there.