Partial non-Fourier encoded MRI

MRI is by nature a Fourier encoded imaging modality. But MRI is enriched and made all the more powerful and flexible by the fact that it also includes elements of non-Fourier encoding, such as slice selection. Our goal is to develop a partial non-Fourier encoding methodology that is fully integrated with, and is complementary to, existing MR encoding approaches. The word ´partial´ is used to emphasize that non-Fourier encoding is presented as complement to standard Fourier-encoded methods. Our focus is to determine where and how non-Fourier encoding can enhance existing MRI data acquisition protocols, particularly to increase the speed of dynamic applications. The specific advantages of non-Fourier encoding we have identified are; (1) that it offers the flexibility to employ encoding functions that are close to the theoretical optimum for a given application, (2) that it offers the ability to employ true multiple resolutions within the imaging volume, (3) that point-spread-functions free of ringing artifact can be made, (4) that robust reduced field-of-view imaging is enabled, and (5) that its flexibility can be exploited to enhance parallel imaging approaches. To realize the significant advantages of non-Fourier encoding, technical advances, in particular the development of practical 2D RF excitation approaches, are necessary. This is the focus of the current report.