Impact of Scan Location on Visualization Characteristics of the Lateral Rectus-Superior Rectus Band with High-Resolution MR Imaging.

BACKGROUND AND PURPOSE: Degeneration of lateral rectus-superior rectus (LR-SR) band has been implicated in the pathogenesis of acquired strabismus conditions, including the sagging eye syndrome. The purpose of this study was to analyze the imaging features of this band as imaged with magnetic resonance imaging at different orbital scan locations. To analyze the imaging features of the LR-SR band as imaged with MRI at different orbital scan locations.

MATERIALS AND

METHODS

The LR-SR band features of patients who underwent high-resolution MRI for nonorbital pathology were evaluated at predefined locations by 2 independent readers. Analyzed features included: 1) visibility, 2) continuity, and 3) superotemporal bowing of LR-SR band in a binary manner at 2.5 mm anterior (zone I), at (zone II), and posterior (zone III) to the globe-optic nerve junction.

RESULTS

Forty-eight orbits of 26 patients with an age range of 58-86 years were included. Visualization of the LR-SR band was significantly higher in zone I (89.6%) compared with zone II (79.2%) (P = .03) and with zone III (47.9%) (P < .001). Among the orbits in which the LR-SR band was visualized, band continuity was most frequently observed in zone I (94.7%), compared with zone II (68.4%) (P = .002) and in zone III (52.2%) (P < .001). Superotemporal bowing was detected with higher frequency posteriorly, rising from 21.1% in zone I to 47.4% in zone II (P = .002) and to 56.5% in zone III (P < .001). A higher degree of reproducibility for LR-SR band visibility and continuity was noted in anterior scan locations.

CONCLUSIONS

The LR-SR band is most consistently visualized on coronal MR images obtained anterior to the globe-optic nerve junction, while degenerative changes are more frequently observed in posterior scan locations. Establishing and reporting a standardized coronal imaging plane referenced to a consistent anatomic landmark may improve reproducibility and comparability of the LR-SR band across studies and allow for more robust clinical interpretation.