<qa>  What is the purpose of the proposed protocol?Magnetic resonance imaging MRI studies yield important information on the structure and function of various body systems including the brain, muscles, joints, heart, blood vessels and other body areas. Unlike clinical MRI imaging, scientific applications often utilize techniques that either requires de-novo development or modification of existing research or commercially available protocols before implementation in clinical studies. The proposed protocol is intended to allow MRI scanning on human subjects for the development and refinement of MRI scanning procedures before implementation in larger scale clinical National Institute on Aging NIA research studies. We will evaluate a variety of MRI pulse sequences on normal volunteers and individuals with a variety of medical conditions to determine optimal protocols for use in normal volunteers and patient populations. In addition, participants can be recruited and scanned to provide additional data for already approved NIA studies. 