Imaging mesial temporal lobe activation during scene encoding: comparison of fMRI using BOLD and arterial spin labeling.

@article{citeulike:2698832, abstract = {Memory encoding is a critical brain function subserved by the hippocampus (HP) and mesial temporal lobe (mTL) structures. Visualization of mTL memory activation with BOLD fMRI is complicated by the presence of static susceptibility gradients in this region. Arterial spin labeled (ASL) perfusion fMRI offers an alternative approach not dependent on susceptibility contrast that instead suffers from lower intrinsic signal-to-noise ratio. An improved ASL perfusion fMRI approach combining pseudo-continuous ASL and a T(2)*-insensitive sequence (GRASE) with background suppression was compared to BOLD fMRI at 3 T during a scene encoding task known to activate the HP. Overall, an approximate sixfold sensitivity increase of ASL fMRI was achieved, with improved coverage in the anterior mTL, while suppression of the static tissue enhanced the stability of the ASL series by a factor of 2.4. Perfusion fMRI using this approach with 4 mm isotropic resolution yielded better localized and stronger group activation maps than BOLD fMRI at a standard resolution of 3 mm isotropic voxels. Increasing the resolution for BOLD to 2.5 mm isotropic produced stronger mTL and hippocampal activation in the group and individual subjects than the ASL technique, due to superior temporal resolution and reduced partial volume effects. Future improvements in ASL spatial and temporal resolution would allow the benefits of both approaches to be combined to further enhance the sensitivity for detecting mTL activation during memory encoding.}, address = {Center for Functional Neuroimaging, Department of Neurology, University of Pennsylvania Medical Center, Philadelphia, PA 19104, USA.}, author = {Fern\'{a}ndez-Seara, M. A. and Wang, J. and Wang, Z. and Korczykowski, M. and Guenther, M. and Feinberg, D. A. and Detre, J. A. }, citeulike-article-id = {2698832}, doi = {10.1002/hbm.20366}, issn = {1065-9471}, journal = {Human brain mapping}, keywords = {jc-hbm}, month = {December}, number = {12}, pages = {1391--1400}, posted-at = {2008-04-22 03:32:48}, priority = {2}, title = {Imaging mesial temporal lobe activation during scene encoding: comparison of fMRI using BOLD and arterial spin labeling.}, url = {http://dx.doi.org/10.1002/hbm.20366}, volume = {28}, year = {2007} }

TY - JOUR ID - citeulike:2698832 L3 - citeulike-article-id:2698832 TI - Imaging mesial temporal lobe activation during scene encoding: comparison of fMRI using BOLD and arterial spin labeling. JF - Human brain mapping VL - 28 IS - 12 SP - 1391 EP - 1400 AD - Center for Functional Neuroimaging, Department of Neurology, University of Pennsylvania Medical Center, Philadelphia, PA 19104, USA. SN - 1065-9471 N2 - Memory encoding is a critical brain function subserved by the hippocampus (HP) and mesial temporal lobe (mTL) structures. Visualization of mTL memory activation with BOLD fMRI is complicated by the presence of static susceptibility gradients in this region. Arterial spin labeled (ASL) perfusion fMRI offers an alternative approach not dependent on susceptibility contrast that instead suffers from lower intrinsic signal-to-noise ratio. An improved ASL perfusion fMRI approach combining pseudo-continuous ASL and a T(2)*-insensitive sequence (GRASE) with background suppression was compared to BOLD fMRI at 3 T during a scene encoding task known to activate the HP. Overall, an approximate sixfold sensitivity increase of ASL fMRI was achieved, with improved coverage in the anterior mTL, while suppression of the static tissue enhanced the stability of the ASL series by a factor of 2.4. Perfusion fMRI using this approach with 4 mm isotropic resolution yielded better localized and stronger group activation maps than BOLD fMRI at a standard resolution of 3 mm isotropic voxels. Increasing the resolution for BOLD to 2.5 mm isotropic produced stronger mTL and hippocampal activation in the group and individual subjects than the ASL technique, due to superior temporal resolution and reduced partial volume effects. Future improvements in ASL spatial and temporal resolution would allow the benefits of both approaches to be combined to further enhance the sensitivity for detecting mTL activation during memory encoding. KW - jc-hbm AU - Fernández-Seara, MA AU - Wang, J AU - Wang, Z AU - Korczykowski, M AU - Guenther, M AU - Feinberg, DA AU - Detre, JA PY - 2007/12// UR - http://dx.doi.org/10.1002/hbm.20366 ER -