MR imaging of orbital tumors with CT and ultrasound correlations.

Fourteen patients with various orbital space-occupying lesions were studied by magnetic resonance (MR) imaging with a 0.15 T imager using spin-echo and inversion-recovery pulse sequences. Computed tomographic and ultrasonographic (US) examinations were done in 13 of these patients. All 14 lesions could be demonstrated by MR. Magnetic resonance was found to be better than US but not as good as CT in providing morphological details. Regarding tissue characterization, US was the most useful among the three modalities. With the T2-weighted spin-echo pulse sequence, a possible trend in tissue characterization could be shown. From our preliminary experience, we conclude that MR imaging using a 0.15 T resistive magnet offers no distinct advantage over the combination of CT and US in the diagnosis of orbital tumors.