“The goal of diffusion tensor imaging is to image the diffusion of water in the brain. DTI uses the fact that water has a lot of these hydrogens, which align to the magnetic field that is applied. So what we do is magnetize a slice of the brain, wait, and then read out that slice of the brain again and again and again, using varying gradient fields of magnetization.
What happens is that water molecules that moved during this magnetization will have a different magnetization than their neighboring water molecules which leads to a change in image contrast. When you do this in more than two directions you will be actually be able to also calculate the direction of water diffusion. “
There is a great how-to-ism all over the world, and every person, particularly the modern contemporary mind, has become a how-to-er: how to do this, how to do that, how to grow rich, how to be successful, how to influence people and win friends, how to meditate, even how to love. The day is not far off when some stupid guy is going to ask how to breathe. It is not a question of how at all. Don’t reduce life into technology. Life reduced into technology loses all flavor of joy.