Lateral Geniculate Nucleus: Anatomic and Functional Identification by Use of MR Imaging
Norihiko Fujitaa,
Hisashi Tanakaa,
Mayako Takanashia,
Norio Hirabukia,
Kazuo Abea,
Hideaki Yoshimuraa and
Hironobu Nakamuraa
a From the Departments of Radiology (N.F., H.T., N.H., H.Y., H.N.) and Neurology (M.T., K.A.), Osaka University Medical School, Osaka, Japan.
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FIG 1. Images of participant 3. All images were obtained 4 mm inferior to the bicommissure line.
A, Proton density–weighted image (3000/14/2) shows the LGN (black arrowheads) bordered sharply by the optic radiation (OR) and the posterior limb of the internal capsule (PL). The medial geniculate nucleus can be seen as a small rounded eminence adjacent to the ambient cistern (white arrowheads).
B, Activation map superimposed on the proton density–weighted image shows 3-pixel clustered activation at the anatomically identified location of each LGN. Red pixels represent activation.
C, T2-weighted image (3000/85/2). The LGN is only faintly visible and its borders are difficult to identify. Note the bandlike areas of slightly higher intensity, compared with the surrounding area, in the posterior third quarter of the posterior limb (arrowheads). SC indicates the superior colliculus; HP, hippocampus.
D, T1-weighted magnetization-prepared rapid gradient-echo image (13.5/7/2; inversion time, 300 ms; resectioned). The LGN is only faintly visible, and its borders are difficult to identify.
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FIG 2. Images of participant 7.
A, Proton density–weighted axial image (3000/14/2) obtained 4 mm inferior to the bicommissure line through the LGN (arrowheads). SC indicates the superior colliculus.
B, Proton density–weighted coronal image (3000/14/2), obtained through the LGN (arrowheads), corresponds to the horizontal black line in D. HP indicates the hippocampus.
C, Proton density–weighted left parasagittal image (3000/14/2) obtained through the LGN (black arrowhead) corresponds to the vertical black line in D. The white arrowhead indicates the anterior commissure. Pu indicates the putamen; Pul, pulvinar.
D, Axial activation map superimposed on a proton density–weighted image shows LGN activation of 2 and 3 pixels on the right and left sides, respectively.
E, Coronal image with superimposed activated pixels shown in D.
F, Activated pixels of the left LGN are projected and superimposed on the left parasagittal image.
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FIG 3. Images of participant 4.
A, Activation map superimposed on proton density–weighted image (3000/14/2) obtained through the bicommissure line. Of the eight participants, only this participant had LGN activation (arrowheads) shown on two sections (one activated pixel on each).
B, Activation map superimposed on proton density–weighted image (3000/14/2) obtained 4 mm inferior to the bicommissure line. Activated pixels (arrowheads) are shown: two on the right side, and one on the left side. Note the asymmetric appearance of the posterior region of the brain, as seen clearly in the margins of the tentorial notch.
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AJNR - American Journal of Neuroradiology