chapter  12
56 Pages

Adapted Wavelet Techniques for Encoding Magnetic Resonance Images

WithDennis M. Healy, John B. Weaver

We present techniques for signal acquisition in magnetic resonance imaging (MRI) based on recent advances in adapted wavelet theory. These approaches generalize existing MRI encoding schemes, and permit flexible adaptation of encoding to particular imaging tasks.

Various figures of merit for MRI are presented, and their use in selecting a particular encoding approach is discussed. In particular, we summarize an analysis of the signal-to-noise ratios of images formed with this technique, as this is a factor of paramount importance in MRI. Other considerations discussed include imaging time and motion artifacts. Some implementation issues are presented.

An application to fast MRI is presented, in which the encoding scheme is designed to approximate the Karhunen-Loeve basis for a given class of images. The approximate basis is a local cosine basis which is much easier to implement in MRI than the actual Karhunen Loeve basis.