A more precise statement of the image acquisition process is that the image-intensities at each position are attenuated, depending on the strength ( " b "-value ) and direction of the so-called magnetic diffusion gradient, as well as on the local microstructure in which the water molecules diffuse.
12.
The transcellular pathway of transport is important in the intestinal absorption of drug molecules, the other being the diffusion gradient moving from an area of high concentration to an area of low concentration, however, the cell membrane is a hydrophobic environment and will not allow the passive diffusion of charged, hydrophilic, or zwitterion molecules.
