CONJUGATION AND HYBRID IR IMAGING

PURPOSE: To evaluate the use of conjugation with hybrid magnetic reson ance imaging techniques in order to reduce artifacts from inconsistenc ies introduced by T2 decay. MATERIALS AND METHODS: Two phantoms contai ning either oil or water were used to study edge spread function (ESF) and signal-to-noise ratio (S/N) for three hybrid acquisition strategi es (low pass, high pass, and ramp) in which a full set was acquired or with partial acquisition and conjugation. RESULTS: With half the echo es providing coverage of the same amount of k space, signal inconsiste ncies were reduced by a factor of at least e. Conjugation improved ESF degradation, and sequence efficiency increased by over 50%, which com pensated for a loss in S/N. CONCLUSION: The time saved with conjugatio n can be used to nearly double the number of sections acquired for a g iven repetition time (TR) or to obtain two simultaneous echoes instead of one, with reduction of artifacts. Alternatively, the imaging time can be nearly halved for a given TR and number of sections.