So sorry for the late post.
Video : http://www.youtube.com/watch?v=8m_RUVrxhew
The video explains the procedure of Magnetic Resonance Imaging (MRI) in detail.
It is a radiology medical imaging technique that is pain free and non invasive. It's detailed body images that can be from any plane allows for visualization of the structure and function of the body. This in turn allows accurate measurements of body tissue composition. The whole procedure uses an MRI scanner for the images
Advantages: Non intrusive and painless
Disadvantages: Limited use as the equipment and the analysis is expensive
Source : http://www.topendsports.com/testing/tests/magnetic-resonance-imaging.htm