Fumiyuki Mitsumori1, Hidehiro Watanabe1, Nobuhiro Takaya1, Michael Garwood2, Edward Auerbach2, Shalom Michaeli2, Silvia Mangia2
1National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan; 2University of Minnesota
We conducted measurements of apparent transverse relaxation rate at 1.5, 1.9, 3, 4.7, and 7T using a MASE sequence. The regional distribution of the relaxation rate was well described by a linear combination of the regional iron concentration [Fe], and the macromolecular mass fraction fM defined as 1 - water fraction. The B0-dependence of the [Fe] and fM terms was linear and quadratic, respectively. The linear dependence of the [Fe] term was similar to that reported for ferritin solution. The quadratic dependence of the macromolecular term was well explained with an exchange model of water protons with those in macromolecules.