View in EDS HTML Full Text PDF Full Text

Trade‐off between preamplifier noise figure and decoupling in MRI detectors.

Saved in:
Bibliographic Details
Title: Trade‐off between preamplifier noise figure and decoupling in MRI detectors.
Authors: Wang, Wenjun1 (AUTHOR), Zhurbenko, Vitaliy1 (AUTHOR) vz@elektro.dtu.dk, Sánchez‐Heredia, Juan Diego1 (AUTHOR), Ardenkjær‐Larsen, Jan Henrik1 (AUTHOR)
Source: Magnetic Resonance in Medicine. Feb2023, Vol. 89 Issue 2, p859-871. 13p.
Subjects: Preamplifiers, Magnetic resonance imaging, Detectors, Noise
Abstract: Purpose: There is a limit to the maximum achievable preamplifier decoupling. In many cases, this level is not enough. To overcome this limit, the preamplifier noise figure can be compromised for further decoupling increase. This is useful in flexible MRI arrays where ensuring coil insensitivity to changes in other array elements is a challenge. Methods: This work establishes the relation between the preamplifier noise figure and preamplifier decoupling using closed‐form equations. These equations allow the evaluation of preamplifier decoupling properties and benchmark different preamplifiers against each other. The method to design the corresponding decoupling networks is described. The derived generalized design equations, which are not limited to 50 Ω pre‐matched preamplifiers, greatly improve design flexibility and enable use of new amplifiers in MRI detectors. Results: Using the method, the decoupling properties of three preamplifiers are studied. For demonstration, the coil decoupling is further increased by 10.8 dB using one of the preamplifiers. The noise figure is sacrificed by 0.5 dB, which is predicted by equations and verified experimentally. Although examples are shown for 3 T systems at 32.13 MHz and 127.7 MHz, the approach and equations apply to any field strength and nucleus. Conclusion: Preamplifier decoupling can be improved beyond what is possible by traditional approaches. The derived design equations cover a wide range of cases, including inductive coils and self‐resonant low‐impedance and high‐impedance coils. [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
Full text is not displayed to guests.
FullText Links:
  – Type: pdflink
Text:
  Availability: 1
Header DbId: egs
DbLabel: Engineering Source
An: 160509677
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Trade‐off between preamplifier noise figure and decoupling in MRI detectors.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Wang%2C+Wenjun%22">Wang, Wenjun</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Zhurbenko%2C+Vitaliy%22">Zhurbenko, Vitaliy</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> vz@elektro.dtu.dk</i><br /><searchLink fieldCode="AR" term="%22Sánchez‐Heredia%2C+Juan+Diego%22">Sánchez‐Heredia, Juan Diego</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Ardenkjær‐Larsen%2C+Jan+Henrik%22">Ardenkjær‐Larsen, Jan Henrik</searchLink><relatesTo>1</relatesTo> (AUTHOR)
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Magnetic+Resonance+in+Medicine%22">Magnetic Resonance in Medicine</searchLink>. Feb2023, Vol. 89 Issue 2, p859-871. 13p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Preamplifiers%22">Preamplifiers</searchLink><br /><searchLink fieldCode="DE" term="%22Magnetic+resonance+imaging%22">Magnetic resonance imaging</searchLink><br /><searchLink fieldCode="DE" term="%22Detectors%22">Detectors</searchLink><br /><searchLink fieldCode="DE" term="%22Noise%22">Noise</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Purpose: There is a limit to the maximum achievable preamplifier decoupling. In many cases, this level is not enough. To overcome this limit, the preamplifier noise figure can be compromised for further decoupling increase. This is useful in flexible MRI arrays where ensuring coil insensitivity to changes in other array elements is a challenge. Methods: This work establishes the relation between the preamplifier noise figure and preamplifier decoupling using closed‐form equations. These equations allow the evaluation of preamplifier decoupling properties and benchmark different preamplifiers against each other. The method to design the corresponding decoupling networks is described. The derived generalized design equations, which are not limited to 50 Ω pre‐matched preamplifiers, greatly improve design flexibility and enable use of new amplifiers in MRI detectors. Results: Using the method, the decoupling properties of three preamplifiers are studied. For demonstration, the coil decoupling is further increased by 10.8 dB using one of the preamplifiers. The noise figure is sacrificed by 0.5 dB, which is predicted by equations and verified experimentally. Although examples are shown for 3 T systems at 32.13 MHz and 127.7 MHz, the approach and equations apply to any field strength and nucleus. Conclusion: Preamplifier decoupling can be improved beyond what is possible by traditional approaches. The derived design equations cover a wide range of cases, including inductive coils and self‐resonant low‐impedance and high‐impedance coils. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>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.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=160509677
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1002/mrm.29489
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 13
        StartPage: 859
    Subjects:
      – SubjectFull: Preamplifiers
        Type: general
      – SubjectFull: Magnetic resonance imaging
        Type: general
      – SubjectFull: Detectors
        Type: general
      – SubjectFull: Noise
        Type: general
    Titles:
      – TitleFull: Trade‐off between preamplifier noise figure and decoupling in MRI detectors.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Wang, Wenjun
      – PersonEntity:
          Name:
            NameFull: Zhurbenko, Vitaliy
      – PersonEntity:
          Name:
            NameFull: Sánchez‐Heredia, Juan Diego
      – PersonEntity:
          Name:
            NameFull: Ardenkjær‐Larsen, Jan Henrik
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 02
              Text: Feb2023
              Type: published
              Y: 2023
          Identifiers:
            – Type: issn-print
              Value: 07403194
          Numbering:
            – Type: volume
              Value: 89
            – Type: issue
              Value: 2
          Titles:
            – TitleFull: Magnetic Resonance in Medicine
              Type: main
ResultId 1