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.
Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose and treat medical conditions. MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures.MRI does not use ionizing radiation (x-rays).RI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures. MRI does not use ionizing radiation (x-rays).