Metal Screening Questionnaire (MSQ): The MSQ is a list of 18 "yes or no" questions regarding pacemakers, shrapnel, bullets, implants, tattoos, hairpieces, insulin pumps, cochlear implants, staples and metal clips, false eyes, nerve stimulators, dental bridges, replacement valves, intrauterine devices (IUDs), dentures, trans-dermal nicotine patches, surgery, metal in the eyes, claustrophobia, and current pregnancy. In addition the MSQ asks "have you ever been shot at or received treated for metal in your eyes?" The questionnaire is anchored by "Is there any possibility of metal, metal pieces, or metal implants in your body?" Each study participant will be asked to fill-out the MSQ at the assessment visit and the clinician will review the MSQ with the participant during the physical exam.