Highly linear in vivo and close to 1. Brain has a lot of fat but not a big deal in mice. Only fine point is that the density of brain varies depending on fixati

Highly linear in vivo and close to 1. Brain has a lot of fat but not a big deal in mice. Only fine point is that the density of brain varies depending on fixation protocol but almost always by less than 5% if you get the osmolarity of the solution just right.