Normal control between the ages of 18 - 70 years of age who are capable of giving informed consent.
Subjects must not have a condition which would preclude their use for technical development (e.g. paralyzed hemidiaphragm, morbid obesity, claustrophobia, etc.).
Subjects must not have a condition which would present unnecessary risks (e.g. pregnancy, surgery of uncertain type, symptoms of pheochromocystoma or insulinoma, etc.).
Lactating women and subjects with hemoglobinopathies, asthma, or renal or hepatic disease will be excluded from studies involving the administration of contrast agents.
Must not have a contraindication to MR scanning such as surgery that involves metal clips or wires which might be expected to concentrate radiofrequency fields or cause tissue damage from twisting in a magnetic field. Examples include: aneurysm clip; implanted neural stimulator; implanted cardiac pacemaker or autodefibrillator; cochlear implant; ocular foreign body (e.g. metal shavings); insulin pump.