TY - JOUR
T1 - fMRI of the temporal lobe of the awake monkey at 7 T
AU - Goense, Jozien B.M.
AU - Ku, Shih Pi
AU - Merkle, Hellmut
AU - Tolias, Andreas S.
AU - Logothetis, Nikos K.
N1 - Funding Information:
We would like to thank Steffen Stoewer and Chris Petkov for allowing us to use their monkeys, and Thomas Steudel for technical assistance. This work was supported by the Max-Planck Society and by the Intramural Research Program of the NIH (National Institute Neurological Disorders and Stroke) (HM).
PY - 2008/2/1
Y1 - 2008/2/1
N2 - Increasingly 7 T scanners are used for fMRI of humans and non-human primates, promising improvements in signal-to-noise, spatial resolution and specificity. A disadvantage of fMRI at 7 T, but already at 3 T, is that susceptibility artifacts from air-filled cavities like the ear canal and nasal cavity cause signal loss and distortion. This limits the applicability of fMRI in these areas, thereby limiting study of these areas, but it also limits study of processes that span large-scale cortical networks or the entire brain. Our goal is to study the inferior temporal (IT) lobe in awake monkeys because of its importance in object perception and recognition, but the functional signal is degraded by strong susceptibility gradients. To allow fMRI of this region, we used an optimized SE-EPI, which recovers signal lost with GE-EPI and we corrected for susceptibility-induced image distortion. SE-EPI has the added advantage that, in contrast to GE-EPI, where the functional signal derives to a large extent from veins, the SE-EPI signal arises from the microvasculature, and hence it better represents the neural activation. We show fMRI at 7 T of the entire visual pathway in the awake primate with robust and widespread activation in all ventral areas of the brain, including areas adjacent to the ear canal. This allows fMRI of areas that normally suffer from artifact and thus more reliable whole-brain studies.
AB - Increasingly 7 T scanners are used for fMRI of humans and non-human primates, promising improvements in signal-to-noise, spatial resolution and specificity. A disadvantage of fMRI at 7 T, but already at 3 T, is that susceptibility artifacts from air-filled cavities like the ear canal and nasal cavity cause signal loss and distortion. This limits the applicability of fMRI in these areas, thereby limiting study of these areas, but it also limits study of processes that span large-scale cortical networks or the entire brain. Our goal is to study the inferior temporal (IT) lobe in awake monkeys because of its importance in object perception and recognition, but the functional signal is degraded by strong susceptibility gradients. To allow fMRI of this region, we used an optimized SE-EPI, which recovers signal lost with GE-EPI and we corrected for susceptibility-induced image distortion. SE-EPI has the added advantage that, in contrast to GE-EPI, where the functional signal derives to a large extent from veins, the SE-EPI signal arises from the microvasculature, and hence it better represents the neural activation. We show fMRI at 7 T of the entire visual pathway in the awake primate with robust and widespread activation in all ventral areas of the brain, including areas adjacent to the ear canal. This allows fMRI of areas that normally suffer from artifact and thus more reliable whole-brain studies.
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U2 - 10.1016/j.neuroimage.2007.09.038
DO - 10.1016/j.neuroimage.2007.09.038
M3 - Article
C2 - 18024083
AN - SCOPUS:37849033471
SN - 1053-8119
VL - 39
SP - 1081
EP - 1093
JO - NeuroImage
JF - NeuroImage
IS - 3
ER -