A reduced field-of-view method to increase temporal resolution or reduce scan time in cine MRI

In some dynamic applications of MRI, only a part of the field-of-view (FOV) actually undergoes dynamic changes. A class of methods, called reduced-FOV (rFOV) methods, convert the knowledge that some part of the FOV is static or not very dynamic into an increase in temporal resolution for the dynamic part, or into a reduction in the scan time. Although cardiac imaging is an important example of an imaging situation where changes are concentrated in a fraction of the FOV, the rFOV methods developed up to now are not compatible with one of the most common cardiac sequences, the so-called retrospective cine method. The present work is a rFOV method designed to be compatible with cine imaging. An increase by a factor n in temporal resolution or a decrease by n in scan time is obtained in the case where only one nth of the FOV is dynamic (the rest being considered static). Results are presented for both Cartesian and spiral imaging. (C) 2000 Wiley-Liss, Inc.