Addressing phase errors in fat-water imaging using a mixed magnitude/complex fitting method.
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| Title: | Addressing phase errors in fat-water imaging using a mixed magnitude/complex fitting method. |
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| Authors: | Hernando, D.1, Hines, C. D. G.1, Yu, H.2, Reeder, S.B.1,3,4,5 |
| Source: | Magnetic Resonance in Medicine. Mar2012, Vol. 67 Issue 3, p638-644. 7p. |
| Abstract: | Accurate, noninvasive measurements of liver fat content are needed for the early diagnosis and quantitative staging of nonalcoholic fatty liver disease. Chemical shift-based fat quantification methods acquire images at multiple echo times using a multiecho spoiled gradient echo sequence, and provide fat fraction measurements through postprocessing. However, phase errors, such as those caused by eddy currents, can adversely affect fat quantification. These phase errors are typically most significant at the first echo of the echo train, and introduce bias in complex-based fat quantification techniques. These errors can be overcome using a magnitude-based technique (where the phase of all echoes is discarded), but at the cost of significantly degraded signal-to-noise ratio, particularly for certain choices of echo time combinations. In this work, we develop a reconstruction method that overcomes these phase errors without the signal-to-noise ratio penalty incurred by magnitude fitting. This method discards the phase of the first echo (which is often corrupted) while maintaining the phase of the remaining echoes (where phase is unaltered). We test the proposed method on 104 patient liver datasets (from 52 patients, each scanned twice), where the fat fraction measurements are compared to coregistered spectroscopy measurements. We demonstrate that mixed fitting is able to provide accurate fat fraction measurements with high signal-to-noise ratio and low bias over a wide choice of echo combinations. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR] |
| Copyright of Magnetic Resonance in Medicine is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Links: – Type: pdflink Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 71841826 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1002/mrm.23044 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 7 StartPage: 638 Titles: – TitleFull: Addressing phase errors in fat-water imaging using a mixed magnitude/complex fitting method. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Hernando, D. – PersonEntity: Name: NameFull: Hines, C. D. G. – PersonEntity: Name: NameFull: Yu, H. – PersonEntity: Name: NameFull: Reeder, S.B. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 03 Text: Mar2012 Type: published Y: 2012 Identifiers: – Type: issn-print Value: 07403194 Numbering: – Type: volume Value: 67 – Type: issue Value: 3 Titles: – TitleFull: Magnetic Resonance in Medicine Type: main |
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