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). An MRI is a large imaging device that sits in its own room. It uses a harmless magnetic field and radio waves to get clear, sharp pictures of the inside of your brain.An MRI is used to detect bleeding in the brain, tumours or stroke. It is also an excellent device for detecting smaller strokes or strokes in the back of the brain, which other imaging devices can miss.MRI images show even more detail than CT scans, and can be viewed in 3-D on a computer screen.agnetic Resonance Imaging (MRI). An MRI is a large imaging device that sits in its own room. It uses a harmless magnetic field and radio waves to get clear, sharp pictures of the inside of your brain.