TY - JOUR
T1 - Comparison of T2*‐weighted sequences for functional MRI
AU - Hu, Xiaoping
AU - Erhard, Peter
AU - Le, Tuang Huu
AU - Kim, Seong‐Gi ‐G
AU - Menon, Ravi
AU - Andersen, Peter
AU - Adriany, Gregor
AU - Strupp, John P.
AU - Uǧurbil, Kâmil
PY - 1995
Y1 - 1995
N2 - Several sequences, including conventional gradient‐echo sequence (e.g., FLASH), gradient‐echo echo‐planar imaging (EPI), T2* prepared ultrafast gradient echo technique (TurboFLASH), and T2*‐weighted spiral sequence, are currently used for T2*‐weighted functional magnetic resonance imaging. This paper presents a comparison of FLASH, gradient‐echo EPI, and T2*‐prepared TurboFLASH. Experimental results have demonstrated that these sequences have different susceptibility to physiologic fluctuation, which is likely the dominant source of noise. EPI images exhibit the lowest relative fluctuation, while images obtained by FLASH and TurboFLASH, respectively, display similar relative fluctuation. Functional maps generated using these sequences are comparable but exhibit different sensitivity to activation from large vessels. Consequently, interpretation of activation results from various maps should take into account the difference in the sequences.
AB - Several sequences, including conventional gradient‐echo sequence (e.g., FLASH), gradient‐echo echo‐planar imaging (EPI), T2* prepared ultrafast gradient echo technique (TurboFLASH), and T2*‐weighted spiral sequence, are currently used for T2*‐weighted functional magnetic resonance imaging. This paper presents a comparison of FLASH, gradient‐echo EPI, and T2*‐prepared TurboFLASH. Experimental results have demonstrated that these sequences have different susceptibility to physiologic fluctuation, which is likely the dominant source of noise. EPI images exhibit the lowest relative fluctuation, while images obtained by FLASH and TurboFLASH, respectively, display similar relative fluctuation. Functional maps generated using these sequences are comparable but exhibit different sensitivity to activation from large vessels. Consequently, interpretation of activation results from various maps should take into account the difference in the sequences.
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U2 - 10.1002/ima.1850060208
DO - 10.1002/ima.1850060208
M3 - Article
AN - SCOPUS:0029313937
SN - 0899-9457
VL - 6
SP - 184
EP - 190
JO - International Journal of Imaging Systems and Technology
JF - International Journal of Imaging Systems and Technology
IS - 2-3
ER -