Blood longitudinal (T (1)) and transverse (T (2)) relaxation time constants at 11.7 Tesla

作者：Lin Ai Ling^*; Qin Qin; Zhao Xia; Duong Timothy Q

来源：Magnetic Resonance Materials in Physics Biology and Medicine, 2012, 25(3): 245-249.

DOI：10.1007/s10334-011-0287-2

• BOLD fMRI
• High fields
• ASL
• VASO
• TRUST

The goal of the study was to determine blood T (1) and T (2) values as functions of oxygen saturation (Y), temperature (Temp) and hematocrit (Hct) at an ultrahigh MR field (11.7 T) and explore their impacts on physiological measurements, including cerebral blood flow (CBF), blood volume (CBV) and oxygenation determination. %26lt;br%26gt;T (1) and T (2) were simultaneously measured. Temperature was adjusted from 25 to 40A degrees C to determine Temp dependence; Hct of 0.17-0.51 to evaluate Hct dependence at 25 and 37A degrees C; and Y of 40-100% to evaluate Y dependence at 25 and 37A degrees C. Comparisons were made with published data obtained at different magnetic field strengths (B (0)). %26lt;br%26gt;T (1) was positively correlated with Temp, independent of Y, and negatively correlated with Hct. T (2) was negatively correlated with Temp and Hct, but positively correlated with Y, in a non-linear fashion. T (1) increased linearly with B (0), whereas T (2) decreased exponentially with B-0. %26lt;br%26gt;This study reported blood T (1) and T (2) measurements at 11.7 T for the first time. These blood relaxation data could have implications in numerous functional and physiological MRI studies at 11.7 T.

• 出版日期2012-6