Magnetic resonance imaging of the orbit: a preliminary experience

Eleven patients with various space-occupying lesions in the orbit were examined, using a 0.3-tesla superconducting magnet to assess the capabilities and limitations of magnetic resonance (MR) imaging in the investigation of orbital lesions. Although the images provided valuable anatomic data, the bright signal intensity of fat and the partial volume effects of large section thickness resulted in loss of resolution for small, low-signal-intensity structures. The limitations of MR imaging were also reaffirmed by the lack of visualization of calcifications and of the bony orbit. These preliminary results show that MR offers no advantage over x-ray computed tomography except for its lack of ionizing radiation. Further technical improvements are needed before MR imaging will be made useful in this area.