Myelin Water Measurement in the Presence of Myelin Debris

Henry Szu-Meng Chen¹, Nathan Holmes², Jie Liu², Wolfram Tetzlaff², Piotr Kozlowski^1,2

Myelin water fraction (MWF) map and T2 relaxation time of myelin water were obtained from excised rat spinal cord at 3 and 8 weeks post injury. Electron microscopy (EM) was used to quantify myelin water content. MWF and T2 of myelin water at the injured fasciculus gracilis both decreased at 8 weeks. EM result indicated 2 to 3 time more myelin water in myelin debris than in intact myelin, which suggests that MWF is not an accurate measure of content of intact myelin when myelin debris is present due to the increased MWF in myelin debris.