Scanning time efficient slinky for non-contrast MRA at low field

To eliminate slab boundary artifact (SBA) for non-contrast multi-slab three -dimensional time-of-flight magnetic resonance angiogram (3D TOF MRA), we h ave previously developed a novel technique, termed SLINKY (Sliding Interlea ved k(Y)) acquisition in which a thin slab continuously "walks" along the z -axis while data are acquired in an interleaved fashion along the k(Y)-axis . It has been demonstrated in our earlier works that SLINKY can suppress th e SEA without any assumption of blood flow behavior, such as velocity or di rection, At the same time, SLINKY keeps the same SNR as conventional multip le overlapping thin slab acquisition (MOTSA). Yet, this method is sensitive to any phase error along the k(Y) axis. In our earlier application of SLIN KY, we used navigator echoes to measure and correct the phase errors along the k, axis, The cost of using navigator echo collection is an increase in the imaging time. We therefore propose an improved SLINKY technique which d oes not use navigator echo collection for correcting phase errors, reducing the imaging time while keeping the same suppression of slab boundary artif acts. The present study demonstrates that by using a specifically designed RF pulse, the navigator echo collection can be avoided without incurring an y extra ghosting or SNR reduction in the reconstructed images. (C) 1999 Els evier Science Inc.