Parallel and nonparallel simultaneous multislice black-blood double inversion recovery techniques for vessel wall imaging

✍ Scribed by Vitalii V. Itskovich; Venkatesh Mani; Gabor Mizsei; Juan Gilberto S. Aguinaldo; Daniel D. Samber; Frank Macaluso; Paul Wisdom; Zahi A. Fayad

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 478 KB
• Volume: 19
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.20022

✦ Synopsis

Abstract

Purpose

To reduce long examination times of black‐blood vessel wall imaging by acquiring multiple slices simultaneously and by using parallel acquisition techniques.

Materials and Methods

DIR‐rapid acquisition with relaxation enhancement (;RARE) techniques imaging up to 10 simultaneous slices per acquisition with single and multiple 180°‐reinversion pulses were developed. A slab‐selective reinversion multislice DIR‐RARE sequence incorporating generalized autocalibrating partially parallel acquisitions (GRAPPA) imaging was implemented. Four‐channel and eight‐channel carotid coils were built to test these sequences. A total of 11 subjects were studied. Contrast‐to‐noise ratio (CNR) and signal‐to‐noise ratio (SNR) efficiency factor (SEF, SNR/unit time/slice) were measured from aortic images of three healthy subjects to determine optimal MR parameters. The DIR–RARE‐GRAPPA sequence was run on aortas and carotid arteries of the five remaining healthy subjects and three atherosclerotic patients with optimal parameters (acquisition times 12–21 seconds).

Results

SEFs of slab‐selective protocols were significantly higher than those of slice‐selective protocols, and SEFs of DIR‐RARE‐GRAPPA protocols were significantly higher than corresponding non‐GRAPPA protocols (P < 0.05). CNR was not significantly different for all imaging protocols. The DIR‐RARE‐GRAPPA multislice sequence showed 8.35‐fold time improvement vs. single–slice DIR‐2RARE sequence.

Conclusion

Future MRI atherosclerotic plaque studies can be performed in substantially shorter times using these methods. J. Magn. Reson. Imaging 2004;19:459–467. © 2004 Wiley‐Liss, Inc.