Compartmental analysis of brain edema using magnetic resonance imaging.

The potential exists for increasing the sensitivity of magnetic resonance imaging (MRI) to white matter (WM) pathologies by identifying compartments of tissue water. We have found the physical equivalents of myelin-associated biological water compartments in normal and pathologic states by using multiexponential analysis of T2 relaxation. In addition, we have applied this multi-parametric technique for the definition of various types of white matter edemas. We were able to identify some changes in physical compartments visible by MRI with simultaneous changes in biological compartments. We conclude that MRI is a very sensitive method to quantify abnormal accumulation of intracerebral water; however, it is a somewhat limited probe for identifying the biologic compartmentation of edema among the various biological compartments of the brain.