Els Fieremans1, Gregory Lemberskiy2, Jens H. Jensen3, Dmitry S. Novikov2
1Center for Biomedical Imaging, Department of Radiology, New York University, New York, NY, United States; 2Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, United States; 3Center for Biomedical Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
The random permeable barriers model (RPBM) employs the time-dependence of the diffusion coefficient for quantifying cell size and membrane permeability. As an in vivo validation of the RPBM, we performed time-dependent diffusion measurements in the calf muscle of a healthy volunteer over the course of a weight lifting program. The RPBM yields realistic values for muscle fiber diameter and permeability. Additionally as expected, a significant increase in diameter of the gastrocnemius medialis is observed with training. This work demonstrates the feasibility of the RPBM method in quantifying muscle fiber diameter and permeability, and its sensitivity to microstructural changes.