FIGURE 7-14 Magnetic Resonance Imaging The subject is placed in a long metal cylinder that has two sets of magnetic coils arranged at right angles, as shown in the drawing. An additional radiofrequency coil (not shown) surrounds the head, perturbing the static magnetic fields to produce an MRI image of a horizontal section through the head, shown in dorsal view. The density differences in hydrogen atoms show up as colors in the image.

Gregory G. Dimijian/Science Source