Final answer:
The artifact that occurs when the FOV in the phase-encoding direction is smaller than the anatomy is known as 'wrap around' or 'aliasing', where parts of the body are superimposed onto the opposite side of the image.
Step-by-step explanation:
When the Field of View (FOV) in the phase-encoding direction of an MRI machine is smaller than the anatomy being imaged, the resulting artifact is known as 'wrap around' or 'aliasing'. This occurs because the part of the body that extends beyond the FOV is incorrectly mapped or superimposed onto the opposite side of the image. As a result, artifacts appear on the image, which can complicate the diagnosis and require the scan to be repeated with an adjusted FOV that accommodates the full extent of the anatomy.