| Velocity navigator for motion compensated thermometry. | |
MedLine Citation:
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PMID: 21373916 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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OBJECT: Proton resonance frequency shift thermometry is sensitive to breathing motion that leads to incorrect phase differences. In this work, a novel velocity-sensitive navigator technique for triggering MR thermometry image acquisition is presented. MATERIALS AND METHODS: A segmented echo planar imaging pulse sequence was modified for velocity-triggered temperature mapping. Trigger events were generated when the estimated velocity value was less than 0.2 cm/s during the slowdown phase in parallel to the velocity-encoding direction. To remove remaining high-frequency spikes from pulsation in real time, a Kalman filter was applied to the velocity navigator data. A phantom experiment with heating and an initial volunteer experiment without heating were performed to show the applicability of this technique. Additionally, a breath-hold experiment was conducted for comparison. RESULTS: A temperature rise of ΔT = +37.3°C was seen in the phantom experiment, and a root mean square error (RMSE) outside the heated region of 2.3°C could be obtained for periodic motion. In the volunteer experiment, a RMSE of 2.7°C/2.9°C (triggered vs. breath hold) was measured. CONCLUSION: A novel velocity navigator with Kalman filter postprocessing in real time significantly improves the temperature accuracy over non-triggered acquisitions and suggests being comparable to a breath-held acquisition. The proposed technique might be clinically applied for monitoring of thermal ablations in abdominal organs. |
Authors:
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Florian Maier; Axel J Krafft; Joshua P Yung; R Jason Stafford; Andrew Elliott; Rüdiger Dillmann; Wolfhard Semmler; Michael Bock |
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Publication Detail:
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Type: Journal Article Date: 2011-03-04 |
Journal Detail:
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Title: Magma (New York, N.Y.) Volume: 25 ISSN: 1352-8661 ISO Abbreviation: MAGMA Publication Date: 2012 Feb |
Date Detail:
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Created Date: 2012-02-03 Completed Date: 2012-07-10 Revised Date: 2014-01-20 |
Medline Journal Info:
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Nlm Unique ID: 9310752 Medline TA: MAGMA Country: Germany |
Other Details:
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Languages: eng Pagination: 15-22 Citation Subset: IM |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Algorithms Body Temperature Echo-Planar Imaging / methods Equipment Design Hot Temperature Humans Image Processing, Computer-Assisted Magnetic Resonance Imaging / methods* Models, Statistical Motion Phantoms, Imaging Protons Respiration Temperature Time Factors |
| Chemical | |
Reg. No./Substance:
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0/Protons |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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