TY - JOUR
T1 - FMRI contrast at high and ultrahigh magnetic fields
T2 - Insight from complementary methods
AU - Ciobanu, Luisa
AU - Solomon, Eddy
AU - Pyatigorskaya, Nadya
AU - Roussel, Tangi
AU - Le Bihan, Denis
AU - Frydman, Lucio
N1 - LC acknowledges UNIRS Laboratory (NeuroSpin/I2BM/DSV/CEA) for partially supporting this work, and Boucif Djemai for help with animal handling. Financial support from the EU (through ERC Advanced Grant # 246754), the Kimmel Institute for Magnetic Resonance and the generosity of the Perlman Family Foundation, are gratefully acknowledged. TR acknowledged the EC Marie Curie Action ITN METAFLUX (project 264780) for a stipend. This work was also supported by grants GIS-IBISA-2010 (France) and by the Israel Science Foundation (grant 795/13).
PY - 2015/6/1
Y1 - 2015/6/1
N2 - This manuscript examines the origins and nature of the function-derived activation detected by magnetic resonance imaging at ultrahigh fields using different encoding methods. A series of preclinical high field (7. T) and ultra-high field (17.2. T) fMRI experiments were performed using gradient echo EPI, spin echo EPI and spatio-temporally encoded (SPEN) strategies. The dependencies of the fMRI signal change on the strength of the magnetic field and on different acquisition and sequence parameters were investigated. Artifact-free rat brain images with good resolution in all areas, as well as significant localized activation maps upon forepaw stimulation, were obtained in a single scan using fully refocused SPEN sequences devoid of T2* effects. Our results showed that, besides the normal T2-weighted BOLD contribution that arises in spin-echo sequences, fMRI SPEN signals contain a strong component caused by apparent T1-related effects, demonstrating the potential of such technique for exploring functional activation in rodents and on humans at ultrahigh fields.
AB - This manuscript examines the origins and nature of the function-derived activation detected by magnetic resonance imaging at ultrahigh fields using different encoding methods. A series of preclinical high field (7. T) and ultra-high field (17.2. T) fMRI experiments were performed using gradient echo EPI, spin echo EPI and spatio-temporally encoded (SPEN) strategies. The dependencies of the fMRI signal change on the strength of the magnetic field and on different acquisition and sequence parameters were investigated. Artifact-free rat brain images with good resolution in all areas, as well as significant localized activation maps upon forepaw stimulation, were obtained in a single scan using fully refocused SPEN sequences devoid of T2* effects. Our results showed that, besides the normal T2-weighted BOLD contribution that arises in spin-echo sequences, fMRI SPEN signals contain a strong component caused by apparent T1-related effects, demonstrating the potential of such technique for exploring functional activation in rodents and on humans at ultrahigh fields.
UR - http://www.scopus.com/inward/record.url?scp=84925870880&partnerID=8YFLogxK
U2 - 10.1016/j.neuroimage.2015.03.018
DO - 10.1016/j.neuroimage.2015.03.018
M3 - مقالة
SN - 1053-8119
VL - 113
SP - 37
EP - 43
JO - NeuroImage
JF - NeuroImage
ER -