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Accelerating MR elastography: a multiecho phase-contrast gradient-echo sequence.

Stefan Maderwald·Kai Uffmann·Craig J Galbán·Armin de Greiff·Mark E Ladd
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Abstract

PURPOSE: To demonstrate the feasibility of using a multiecho phase-contrast (PC) gradient-echo sequence with motion-sensitizing gradient (MSG) to accelerate MR elastography (MRE) acquisitions in comparison to single-echo PC sequences. MATERIALS AND METHODS: The sequence was implemented and compared with a conventional single-echo sequence as the standard of reference in both agarose phantoms and in vivo in the biceps of three healthy volunteers. For reconstruction of the elasticity modulus, a local frequency estimation (LFE) algorithm was used. ETL factors of 1-16 were evaluated. RESULTS: Phantom experiments demonstrated excellent consistency between single-echo and multiecho measurements in terms of wave equivalency, SNR, and reconstructed shear modulus. Additionally, the in vivo MRE examinations showed an excellent correspondence to the single-echo results. Minor loss of wave amplitude was observed at higher ETL factors. CONCLUSION: The results demonstrate that a multiecho sequence is suitable for accelerating MRE in nearly homogeneous tissue, such as muscle. It provides equivalent elasticity values in a significantly reduced scan time compared to a single-echo sequence. The maximum achievable ETL factor must be individually determined for the target tissue.

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AccelerationAdultAgarAlgorithmsElasticityFeasibility StudiesHumansMagnetic Resonance ImagingMaleMuscle, SkeletalPhantoms, ImagingShear StrengthStress, MechanicalVibrationEvaluation StudyJournal ArticleResearch Support, Non-U.S. Gov't

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Stefan Maderwald, Kai Uffmann, Craig J Galbán, Armin de Greiff, Mark E Ladd. 2006. Accelerating MR elastography: a multiecho phase-contrast gradient-echo sequence.. https://doi.org/10.1002/jmri.20570

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