Two Anesthetic Techniques in Magnetic Resonance Imaging (MRI)

Inclusion Criteria: 1. Subjects presenting as out-patients, scheduled to receive an anesthetic for MRI of body (spine, chest, abdomen, and/or pelvis) and/or extremity (arm and/or leg). 2. The subject must be a candidate for both anesthetic techniques. This decision will be made by a staff member of the Department of Anesthesiology. This staff member will not be a member of the study team and will obtain the consent for Anesthesia. 3. The subjects must be 12 months to 7 years (inclusive of the seventh year). 4. The subject's legally authorized representative has given written informed consent to participate in the study. Exclusion Criteria: 1. The subject is residing in the Pediatric Intensive Care Unit, the Cardiac Intensive Care Unit, or Neonatal Intensive Care Unit. 2. Anxiolytic medication is ordered before the MRI (e.g., midazolam or ketamine). 3. The subject has a history or a family (parent or sibling) history of malignant hyperthermia. 4. The subject has life-threatening, medical conditions (American Society of Anesthesiologists Physical Status 4, 5 or 6). * The American Society of Anesthesiologists (ASA) classification scale is a measure of physical status or how healthy the patient is. * For our study, we will focus on children which are defined as ASA I, II or III which means a healthy child (ASA I), a child with a systemic disease that is mild and well controlled (ASA II) or a child with systemic disease that is severe and controlled (ASA III). 5. The subject is allergic to or has a contraindication to any of the drugs used in the study. 6. The subject has previously been treated under this protocol. 7. The subject has a tracheostomy or other mechanical airway device. 8. The subject has received within the past 12 hours an oral or intravenous alpha-adrenergic, beta-adrenergic agonist, or antagonist drugs (e.g., clonidine, propranolol, albuterol). 9. The subject is not scheduled to receive anesthesia-sedation care for the MRI. 10. The subject received one of the anesthetic regimens for the same MRI during the past six months.