A study on patients with Temporal Lobe Epilepsy showed a relationship of a circle in a plane defined by FA and trace jointly
Wang J, Yang C, Lu Y, Wai Y, Chy T
Increased diffusivity was detected in the epileptic hippocampus and the ipsilateral temporal structures associated with a decreased anisotropy along the temporal lobe. However, from such observations it is difficult to determine the microstructural changes because the change in mean diffusivity and anisotropy is not directly related and therefore segmented. This study showed a simple relationship existed, which defined a circle in a coordinate system of FA and normalized trace. The combined information described the change in the microenvironment in water diffusion in epileptic patients.