PMID- 26192998
OWN - NLM
STAT- MEDLINE
DCOM- 20171214
LR  - 20191008
IS  - 1522-2594 (Electronic)
IS  - 0740-3194 (Print)
IS  - 0740-3194 (Linking)
VI  - 75
IP  - 6
DP  - 2016 Jun
TI  - Sensitivity Enhancement of an Inductively Coupled Local Detector Using a 
      HEMT-Based Current Amplifier.
PG  - 2573-8
LID - 10.1002/mrm.25850 [doi]
AB  - PURPOSE: To improve the signal transmission efficiency and sensitivity of a local 
      detection coil that is weakly inductively coupled to a larger receive coil. 
      METHODS: The resonant detection coil is connected in parallel with the gate of a 
      high electron mobility transistor (HEMT) transistor without impedance matching. 
      When the drain of the transistor is capacitively shunted to ground, current 
      amplification occurs in the resonator by feedback that transforms a capacitive 
      impedance on the transistor's source to a negative resistance on its gate. 
      RESULTS: High resolution images were obtained from a mouse brain using a small, 
      11 mm diameter surface coil that was inductively coupled to a commercial, phased 
      array chest coil. Although the power consumption of the amplifier was only 88 muW, 
      14 dB gain was obtained with excellent noise performance. CONCLUSION: An 
      integrated current amplifier based on a HEMT can enhance the sensitivity of 
      inductively coupled local detectors when weakly coupled. This amplifier enables 
      efficient signal transmission between customized user coils and commercial 
      clinical coils, without the need for a specialized signal interface. Magn Reson 
      Med 75:2573-2578, 2016. Published 2015. This article is a U.S. Government work 
      and is in the public domain in the USA.
CI  - Published 2015 This article is a U.S. Government work and is in the public domain 
      in the USA.
FAU - Qian, Chunqi
AU  - Qian C
AD  - Laboratory of Functional and Molecular Imaging, National Institute of 
      Neurological Disorders and Stroke, National Institutes of Health, Bethesda, 
      Maryland, USA.
AD  - Department of Radiology, Michigan State University, East Lansing, Michigan, USA.
FAU - Duan, Qi
AU  - Duan Q
AD  - Laboratory of Functional and Molecular Imaging, National Institute of 
      Neurological Disorders and Stroke, National Institutes of Health, Bethesda, 
      Maryland, USA.
FAU - Dodd, Steve
AU  - Dodd S
AD  - Laboratory of Functional and Molecular Imaging, National Institute of 
      Neurological Disorders and Stroke, National Institutes of Health, Bethesda, 
      Maryland, USA.
FAU - Koretsky, Alan
AU  - Koretsky A
AD  - Laboratory of Functional and Molecular Imaging, National Institute of 
      Neurological Disorders and Stroke, National Institutes of Health, Bethesda, 
      Maryland, USA.
FAU - Murphy-Boesch, Joe
AU  - Murphy-Boesch J
AD  - Laboratory of Functional and Molecular Imaging, National Institute of 
      Neurological Disorders and Stroke, National Institutes of Health, Bethesda, 
      Maryland, USA.
LA  - eng
GR  - R00 EB016753/EB/NIBIB NIH HHS/United States
GR  - Z99 NS999999/Intramural NIH HHS/United States
PT  - Journal Article
DEP - 20150720
PL  - United States
TA  - Magn Reson Med
JT  - Magnetic resonance in medicine
JID - 8505245
SB  - IM
MH  - *Amplifiers, Electronic
MH  - Animals
MH  - Equipment Design
MH  - Image Processing, Computer-Assisted/*methods
MH  - Magnetic Resonance Imaging/*instrumentation/*methods
MH  - Mice
MH  - Signal Processing, Computer-Assisted/*instrumentation
PMC - PMC4720591
MID - NIHMS706089
OTO - NOTNLM
OT  - HEMT
OT  - MRI
OT  - current amplifier
OT  - inductive coupling
OT  - negative resistance
EDAT- 2015/07/21 06:00
MHDA- 2017/12/15 06:00
PMCR- 2017/06/01
CRDT- 2015/07/21 06:00
PHST- 2015/04/20 00:00 [received]
PHST- 2015/06/12 00:00 [revised]
PHST- 2015/06/27 00:00 [accepted]
PHST- 2015/07/21 06:00 [entrez]
PHST- 2015/07/21 06:00 [pubmed]
PHST- 2017/12/15 06:00 [medline]
PHST- 2017/06/01 00:00 [pmc-release]
AID - 10.1002/mrm.25850 [doi]
PST - ppublish
SO  - Magn Reson Med. 2016 Jun;75(6):2573-8. doi: 10.1002/mrm.25850. Epub 2015 Jul 20.