Unexplained weight loss is defined as the unintentional loss of at least 10 pounds or 5 percent of body weight over a period of 6 to 12 months. This would be equivalent to a 200-pound man losing 10 pounds or a 130-pound woman losing six to seven pounds.
What It Is. Magnetic resonance imaging (MRI) of the brain is a safe and painless test that uses a magnetic field and radio waves to produce detailed images of the brain and the brain stem. An MRI differs from a CAT scan (also called a CT scan or a computed axial tomography scan) because it does not use radiation.
MRI has become widely used because the pictures are so detailed that the radiologist can see even tiny changes. This accuracy helps in the early detection of disease and injury, allowing effective treatment planning. There are no known side effects of an MRI scan, and it is normally a totally pain-free procedure. Some people should not have an MRI scan. If any of the following applies to you, please contact us on the number on your appointment letter: 1  You have a heart pacemaker.