Closed MRIs have been around longer than open MRIs, and they use a capsule-like environment in which you lie to get high-quality images. A huge magnet and radio wave are used in the system to send and receive signals to and from your body. The returned impulses are converted into images by a computer connected to the scanner.Closed MRIs have been around longer than open MRIs, and they use a capsule-like environment in which you lie to get high-quality images. A huge magnet and radio wave are used in the system to send and receive signals to and from your body. The returned impulses are converted into images by a computer connected to the scanner.