Login Register Cart 0
Generic placeholder image

Current Medical Imaging

Editor-in-Chief

ISSN (Print): 1573-4056
ISSN (Online): 1875-6603

Back
Journal Home About Journal Editorial Board Journal Insight Current Issue Volumes/Issues
Subscribe
Research Article

Artifacts by Misalignment of Cardiac Magnetic Resonance Phased-array Coil Elements: From Simulation to In vivo Test

Author(s): Daniele De Marchi, Alessandra Flori, Nicola Martini and Giulio Giovannetti*

Volume 15, Issue 3, 2019

Page: [301 - 307] Pages: 7

DOI: 10.2174/1573405613666171024150250

Price: $65

Abstract

Background: Cardiac magnetic resonance evaluations generally require a radiofrequency coil setup comprising a transmit whole-body coil and a receive coil. In particular, radiofrequency phased-array coils are employed to pick up the signals emitted by the nuclei with high signal-tonoise ratio and a large region of sensitivity.

Methods: Literature discussed different technical issues on how to minimize interactions between array elements and how to combine data from such elements to yield optimum Signal-to-Noise Ratio images. However, image quality strongly depends upon the correct coil position over the heart and of one array coil portion with respect to the other.

Results: In particular, simple errors in coil positioning could cause artifacts carrying to an inaccurate interpretation of cardiac magnetic resonance images.

Conclusion: This paper describes the effect of array elements misalignment, starting from coil simulation to cardiac magnetic resonance acquisitions with a 1.5 T scanner.

Phased-array coil simulation was performed using the magnetostatic approach; moreover, phantom and in vivo experiments with a commercial 8-elements cardiac phased-array receiver coil permitted to estimate signal-to-noise ratio and B1 mapping for aligned and shifted coil.

Keywords: Cardiac magnetic resonance, MRI artifacts, phased array coil, coil simulation, signal-to-noise ratio, MRI practice.

Graphical Abstract

[1]
Roemer PB, Edelstein WA, Hayes CE, Souza SP, Mueller OM. The NMR phased array. Magn Reson Med 1990; 16: 192-225.
[2]
Giovannetti G, De Marchi D, Pingitore A. Radiofrequency coils and pulse sequences for cardiac magnetic resonance applications: New perspectives and future developments. Rev Cardiovasc Med 2016; 17(3/4): 124-30.
[3]
Graessl A, Renz W, Hezel F, et al. Modular 32-channel transceiver coil array for cardiac MRI at 7.0T. Magn Reson Med 2014; 72: 276-90.
[4]
Wright SM, Wald LL. Theory and application of array coils in MR spectroscopy. NMR Biomed 1997; 10: 394-410.
[5]
Larsson EG, Erdogmus D, Yan R, Principe JC, Fitzsimmons JR. SNR-optimality of sum-of-squares reconstruction for phased-array magnetic resonance imaging. J Magn Reson 1983; 163: 121-3.
[6]
Constantinides CD, Atalar E, McVeigh ER. Signal-to-noise measurements in magnitude images from NMR phased arrays. Magn Reson Med 1997; 38: 852-7.
[7]
Giovannetti G, Viti V, Positano V, et al. Coil sensitivity map-based filter for phased-array image reconstruction in magnetic resonance imaging. Int J Biomed Eng Technol 2007; 1: 4-17.
[8]
Saremi F, Grizzard JD, Kim RJ. Optimizing cardiac MR imaging: Practical remedies for artifacts. Radiographics 2008; 28: 1161-87.
[9]
Jin JM. Electromagnetic analysis and design in magnetic resonance imaging CRC Press, Boca Raton, Florida 1998.
[10]
Giovannetti G. Comparison between circular and square loops for low-frequency magnetic resonance applications: Theoretical performance estimation. Conc Magn Reson Part B 2016; 46B: 146-55.
[11]
Hartwig V, Vanello N, Giovannetti G, et al. B1+/actual flip angle and reception sensitivity mapping methods: Simulationand comparison. Magn Reson Imaging 2011; 29: 717-22.
[12]
Schneider CA, Rasband WS, Eliceiri KW. NIH Image to ImageJ: 25 years of image analysis. Nat Methods 2012; 9(7): 671-5.
[13]
Martini N, Santarelli MF, Giovannetti G, et al. Noise correlations and SNR in phased-array MRS. NMR Biomed 2010; 23: 66-73.
[14]
Smith TB, Nayak KS. MRI artifacts and correction strategies. Imaging Med 2010; 2(4): 445-57.
[15]
Atalay MK, Poncelet BP, Kantor HL, Brady TJ, Weisskoff RM. Cardiac susceptibility artifacts arising from the heart-lung interface. Magn Reson Med 2001; 45(2): 341-5.
[16]
Graf H, Lauer UA, Berger A, Schick F. RF artifacts caused by metallic implants or instruments which get more prominent at 3 T: an in vitro study. Magn Reson Imaging 2005; 23: 493-9.
[17]
Liao J-R, Pauly JM, Brosnan TJ, Pelc NJ. Reduction of motion artifacts in cine MRI using variable-density spiral trajectories. MRM 1997; 37: 569-75.
[18]
Pipe JG. Motion correction with PROPELLER MRI: Application to head motion and free-breathing cardiac imaging. Magn Reson Med 1999; 42: 963-9.
[19]
Dietrich O, Reiser MF, Schoenberg SO. Artifacts in 3-T MRI: Physical background and reduction strategies. Eur J Radiol 2008; 65(1): 29-35.

Rights & Permissions Print Cite
Article Metrics
21
1
© 2024 Bentham Science Publishers | Privacy Policy