Orbital and ocular imaging using 3-and 1.5-T MR imaging systems

CT scanning and MR imaging of the eye and orbit have significantly enhanced the diagnosis of ocular and orbital lesions [1-21]. The anatomy and pathologic findings of the bony orbit, surrounding structures of the eye, and optic pathways can now be visualized with exquisite detail, so that the diagnosis of pathologic conditions can be made with much more certainty than in the past [1-21]. The evolution of advanced technologies has greatly influenced and aided in the differentiation of orbital and ocular lesions. Oplithalmologic diagnostic evaluation, in particular, has significantly improved with the use of imaging modalities such as ultrasound and MR imaging. The increasing availability of clinical highfield MR imaging at 3 Tesla (3-T) scanners holds the promise of making 3-T MR imaging scanners more available for routine clinical use. The purpose of this article is to describe the application of the 3-T MR imaging scanner in orbital and ocular pathologic findings and, in particular, whether the 3-T MR imaging scanner improves the imaging evaluation of orbital and ocular lesions. In keeping with the purpose of this issue, we review the MR imaging characteristics of selected patients (Table 1) who presented with various orbital and ocular disorders and underwent scanning on a 3-T MR imaging scanner. Some of these patients also underwent scanning on a 1.5-T MR imaging unit. An attempt is made to emphasize the diagnostic patterns of common orbital and ocular lesions on 3-T MR imaging sequences.