J Korean Radiol Soc.
1994 Jun;30(6):999-1002.
Position and Width of Normal Adult Optic Chiasm as Measured in Coronal MRI
Abstract
- PURPOSE
Purpose :To evaluate the position and transverse dimension of the adult optic chiasm in normal Korean adult.
MATERIALS AND METHODS
The authors analysed 3D coronal volume images (TR/TE= 30/13, flip angle= 30 degrees) of 136 normal adult subjects without known visual abnormality. All MRI examinations were performed using a 0.5T system. MRI was reviewed retrospectively to determine the position (horizontal and tilted) of the potic chiosm and the transverse dimension of the optic chiasm was measured.
RESULTS
Seventy-five (55%) of 136 normal subjects had horizontal position, and sixty-one (45%) had tilted position. Thirty-eight (62%) of 61 with tilted position showed higher position on the right side, and twenty-three (38%) showed higher position on the side. The average transverse dimension(mean SD) was 15.2 +/- 0.7mm in men and 14.6 +/- 1.0mm in women. The difference of transverse dimension between men and women was statistically significant.
CONCLUSION
Tilted position of the adult optic chiasm on coronal MRI was seen in approximately half of normal adults. The average of transverse dimension of normal optic chiasm was 15mm.
