Magnetic resonance imaging of the orbit.

Magnetic resonance imaging (MRI) employs the nuclear resonance phenomenon to produce images of living tissues. Unlike computed tomography (CT), which relies solely on differences in the propensity of tissues to absorb X-rays to produce various contrasts, MRI offers a wide variety of pulse sequences, each of which exploits differences in the magnetic properties of protons in living tissue to produce contrast resolution. When optimal protocols are used, MRI contrast resolution in the orbital soft tissues is superior to that provided by any other imaging modality. Other advantages of MRI over CT include the ability to select the plane of imaging, and improved safety due to the lack of ionizing radiation.