Subjects for pilot data collection will initially be up to 10 unscreened adult volunteers who have been previously studied on the 1.5-Tesla Signa scanner. Subjects will be required to provide informed consent, and to not have any medical exclusions as noted in the consent form and below, particularly metallic objects and/or pregnancy. Once procedures are optimized, up to 10 pediatric subjects will be studied. These pilot subjects will be derived from the normal control pool of subjects who have been previously studied on the 1.5-Tesla Signa scanner. Informed consent and signed assent will be required, with the same exclusions.