RT Journal Article
SR Electronic
T1 Lateral Geniculate Nucleus: Anatomic and Functional Identification by Use of MR Imaging
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1719
OP 1726
VO 22
IS 9
A1 Norihiko Fujita
A1 Hisashi Tanaka
A1 Mayako Takanashi
A1 Norio Hirabuki
A1 Kazuo Abe
A1 Hideaki Yoshimura
A1 Hironobu Nakamura
YR 2001
UL http://www.ajnr.org/content/22/9/1719.abstract
AB BACKGROUND AND PURPOSE: MR imaging has the potential capacity for noninvasively depicting the anatomy and function of thalamic nuclei. The purpose of this study was to identify the lateral geniculate nucleus (LGN), which is the thalamic relay nucleus for vision, with anatomic and functional MR imaging at 1.5 T.METHODS: Three-millimeter-thick axial images were obtained from eight volunteers by using a double-echo turbo spin-echo sequence for proton density– and T2-weighted contrast and a spin-echo 3D gradient-echo sequence for T1-weighted contrast. Each participant underwent a visual activation experiment using gradient-echo echo-planar imaging at the same location as that of the anatomic study.RESULTS: In all cases, the LGN was recognized on proton density–weighted images as a small wedge-shaped area of high signal intensity relative to that of the surrounding white matter tracts. However, it was difficult to identify the LGN on T1- and T2-weighted images because of the smaller contrast-to-noise ratios between the LGN and the adjacent white matter tracts, compared with those of proton density–weighted images (P < .001). Bilateral thalamic activation and activation in the occipital cortex were shown in all participants. Each region of thalamic activation (23 ± 3 mm2) was localized to the anatomically identified LGN.CONCLUSION: The excellent correspondence between the anatomically and functionally identified LGN confirms that MR imaging is an indispensable method for visualizing functional neuroanatomy in thalamic nuclei.