Nghiên cứu kích thước của các cơ vận nhãn và vị trí của nhãn cầu ở người bình thường bằng cộng hưởng từ

In the evaluation of orbital lesions in thyroid related ophthalmopathy, the size of the extraocular muscles (diameter of the muscle belly, muscle length and overall diameter) and the anterior protuberance of the eyeball from the orbit are the important indicators. These indicators need to be determined in the mature Vietnamese, as a basis for comparison in cases of disease. The authors conducted orbital MR scanning for 60 subjects, aged from 18 to 65, induding 30 males and 30 females. Total of 120 eyes were measured, including both sides. Results showed that, average diameter and length of the extraocular muscles (in mm) were as follows: The superior group (superior rectus and levator palpebrae superioris) - 3.76 + or - 0.48 and 40.00 + or - 1.36, inferior rectus - 4.75 + or - 0.56 and 40.15 + or - 1.90, medial rectus - 3.77 + or - 0.47 and 40.11 + or - 1.66, lateral rectus - 3.03 + or - 0.38 and 39.98 + or - 0.78, diameter of the superior oblique - 2.56 + or - 0.34. Overall diameter was 17.97 + or - 1.98. Mean eyeball position was 7.85 + or - 0.22. MRI proved to be the best diagnostic imaging method for orbital investigation with the high image resolution, multiplanar scanning and without artifact at skull base.