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 i
n a fraction of the FOV, the rFOV methods developed up to now are not compa
tible with one of the most common cardiac sequences, the so-called retrospe
ctive cine method. The present work is a rFOV method designed to be compati
ble 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 presente
d for both Cartesian and spiral imaging. (C) 2000 Wiley-Liss, Inc.