A reduced field-of-view (FOV) imaging technique combines suppression of
signals from outer volume and inflowing blood. Both outer volume and
blood suppression are achieved using an SFQIR (Small-FOV
Quadruple-inversion-Recovery) preparative pulse sequence including two
double-inversion pulse pairs separated by appropriate delays. Within each
pair, inversion pulses are successively applied to the imaged slice and
the slab orthogonal to the imaging plane, with the thickness equal to the
FOV size in the phase-encoding direction. Each double-inversion results
in a reinversion of the magnetization in a central part of the FOV, while
outer areas of the FOV and inflowing blood remain inverted. The SFQIR
module was implemented for single-slice and multislice acquisition with a
fast spin-echo readout sequence. Timing parameters of the sequence
corresponding to the maximal suppression efficiency can be found by
minimizing variation of the normalized signal over the entire range of
T.sub.1 occurring in tissues.