Visit ReviseMRI.com. It includes the K-Space Tool, as well as animated web tutorials on k-space, and over 100 questions and answers on basic MRI physics. With every discussion there are links to further reading both in popular textbooks and online.
The K-Space Tool simulates the manipulation of k-space data before performing the 2DFT in order to create an image. This allows you to see the effects of such manipulations as high-pass (removing low spatial frequencies) and low-pass filters (removing high spatial frequencies), reduced scan percentage, partial Fourier, motion, noise and more. It is inspired by MRI-Toy, a program written by Dr Eltjo Haselhoff.
Complete list of K-Space Resources:
Internet Explorer 5.x or higher, and the Office Animation Runtime are needed for the web tutorials. See Tutorials Help.
Six-inch screw embedded in a cork block, 4.5 MB Quicktime 4+:
Aluminium slab falling slowly, 10.4 MB Quicktime 4+. This demonstrates the Lenz effect, which may have significant implications on the scanning of patients with a particular type of artifical heart valve:
Check out Klaus Scheffler's Spin Zoo.