Magnetic resonance imaging of the orbit. Part II. Clinical applications.

Imaging of the orbit with magnetic resonance imaging (MRI) provides better anatomic detail with T1-weighted sequences and superior visualization of pathologic conditions with T2-weighted sequences. Compared with computerized tomography (CT), MRI has the following advantages: lack of ionizing radiation, direct multiplanar imaging, better contrast resolution, lack of bone artifacts, visualization of bone marrow, superior study of certain neurological disorders, and spectroscopy. Compared with CT, MRI has the following disadvantages: prolonged examination, poorer ability to detect orbital calcifications and cortical bone destruction, poorer spatial resolution, fewer suitable patients, certain image artifacts, high cost of MRI units, and higher cost of MRI examinations.