Journal Article

FZJ-2017-07781

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Adaptive suppression of power line interference in ultra-low field magnetic resonance imaging in an unshielded environment

Huang, X. ; Dong, H. (Corresponding author) ; Qiu, Y. ; Li, B. ; Tao, Q.FZJ* ; Zhang, Y.FZJ* ; Krause, H.-J. (Corresponding author)FZJ* ; Offenhäusser, A.FZJ* ; Xie, X.

2018
Elsevier Amsterdam [u.a.]

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Please use a persistent id in citations: http://hdl.handle.net/2128/16436  doi:10.1016/j.jmr.2017.11.009

Abstract: Power-line harmonic interference and fixed-frequency noise peaks may cause stripe-artifacts in ultra-low field (ULF) magnetic resonance imaging (MRI) in an unshielded environment and in a conductively shielded room. In this paper we describe an adaptive suppression method to eliminate these artifacts in MRI images. This technique utilizes spatial correlation of the interference from different positions, and is realized by subtracting the outputs of the reference channel(s) from those of the signal channel (s) using wavelet analysis and the least squares method. The adaptive suppression method is first implemented to remove the image artifacts in simulation. We then experimentally demonstrate the feasibility of this technique by adding three orthogonal superconducting quantum interference device (SQUID) magnetometers as reference channels to compensate the output of one 2nd-order gradiometer. The experimental results show great improvement in the imaging quality in both 1D and 2D MRI images at two common imaging frequencies, 1.3 kHz and 4.8 kHz. At both frequencies, the effective compensation bandwidth is as high as 2 kHz. Furthermore, we examine the longitudinal relaxation times of the same sample before and after compensation, and show that the MRI properties of the sample did not change after applying adaptive suppression. This technique can effectively increase the imaging bandwidth and be applied to ULF MRI detected by either SQUIDs or Faraday coil in both an unshielded environment and a conductively shielded room.

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Contributing Institute(s):

1. Bioelektronik (ICS-8)
2. JARA-FIT (JARA-FIT)

Research Program(s):

1. 552 - Engineering Cell Function (POF3-552) (POF3-552)
2. 553 - Physical Basis of Diseases (POF3-553) (POF3-553)

Appears in the scientific report 2018

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Database coverage:
; ; Current Contents - Life Sciences ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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