Only patients with a clinical indication for brain MRI examination will undergo 7T MRI. All examinations will be performed without intravenous contrast and in an outpatient setting, without the need for deep sedation or general anesthesia. Although classified by FDA as an investigational device, the 7T MR system has been ruled as a non-significant risk device by the same agency. This finding is stipulated in Guidance for Industry and FDA Staff --Criteria for Significant Risk Investigations of Magnetic Resonance Diagnostic Devices issued July 14, 2003. A copy of the ruling has been uploaded in Section 3.0 for your review. In well over 1000 studies done at 7T in the last decade at multiple institutions (University of Minnesota, Massachusetts General Hospital, NIH), no significant risks have been found. Some subjects have experienced dizziness. A potential concern with MR studies at high fields is radiofrequency heating due to radiofrequency power deposition in the subject. The FDA has set strict guidelines to guard against this risk. Such power deposition increases with the square of the magnetic field strength. However, even at 7T it is possible to stay well within these guidelines, especially with the pulse sequences the investigators will employ. To be 100% sure of compliance with FDA guidelines, the software of the manufacturer monitors power deposition continuously and scans are not possible to implement if the power deposition would exceed guidelines.