MR imaging of orbital mass lesions with contrast agent: a preliminary report.

To investigate the advantage and limit of contrast enhancement in the examination of orbital mass lesions, precontrast T1- and T2-weighted, and postcontrast T1-weighted spin-echo images were retrospectively compared by two experienced observers. Using contrast material, intraocular tumors were well detected and characterized, and several orbital tumors were characterized as to whether cystic or necrotic and intracranial involvement was better evaluated. On the other hand, tumor-fat interface lost conspicuity when tumors showed enhancement. We conclude that gadopentetate-dimeglumine-administered T1-weighted images were helpful in detecting, differentiating and characterizing tumors of the orbit. However, the loss of contrast with fatty tissue is a disadvantage to be considered.