Journal of Magnetics

The Korean Magnetics Society (한국자기학회)
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Effects of NEX on SNR and Artifacts in Parallel MR Images Acquired using Reference Scan

  • Heo, Yeong-Cheol (Department of Radiology, Kyung Hee University Hospital at Gang-dong) ;
  • Lee, Hae-Kag (Department of Computer Science and Engineering, Soonchunhyang University) ;
  • Cho, Jae-Hwan (Department of International Radiological Science, Hallym University of Graduate Studies)
  • Received : 2013.08.12
  • Accepted : 2013.09.23
  • Published : 2013.12.31
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Abstract

The aim of this study was to investigate effects of the number of acquisitions (NEX) on signal-to-noise (SNR) and artifacts in SENSE parallel imaging of magnetic resonance imaging (MRI). 3.0T MR System, 8 Channel sensitivity encoding (SENSE) head coils were used along with an in-vivo phantom. Reference sequence of 3D fast field echo (FFE) was consisted of NEX values of 2, 4, 6, 8, 10 and 12. The T2 turbo spin echo (TSE) sequence used for exams achieved SENSE factors of 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, 2.8, 3.0, 3.2, 3.5, 3.8 and 4.0. Exams were conducted five times for each SENSE factor to measure signal intensity of the object, the posterior phase-encode direction and frequency direction. And SNR was calculated using mean values. SENSE artifacts were identified as background signal intensity in the phase-encoded direction using MRIcro. It was found that SNR increased but SENSE artifacts reduced with NEX of 4, 8 and 12 when the NEX increased in reference scan. It is therefore concluded that image quality can be improved with NEX of 4, 8 and 12 for reference scanning.

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References

  1. C. B. Ahn, J. H. Kim, and Z. H. Cho, IEEE Trans. Med. Imag 5, 1 (1986). https://doi.org/10.1109/MEMB.1986.5006296
  2. B. A. Poser and D. G. Norris, MAGMA 20, 11 (2007). https://doi.org/10.1007/s10334-006-0063-x
  3. P. Mansfield, J. Phys. C 10, 155 (1977).
  4. C. H. Meyer, B. S. Hu, D. G. Nishimura, and A. Macovski, Magn. Reson. Med 28, 202 (1992). https://doi.org/10.1002/mrm.1910280204
  5. J. Hennig, A. Naureth, and H. Friedburg, Magn. Reson. Imag 3, 823 (1986). https://doi.org/10.1002/mrm.1910030602
  6. D. K. Sodickson and W. J. Manning, Magn. Reson. Med. 38, 591 (1997). https://doi.org/10.1002/mrm.1910380414
  7. K. P. Pruessmann, M. Weiger, M. B. Scheidegger, and P. Boesiger, Magn. Reson. Med. 42, 952 (1999). https://doi.org/10.1002/(SICI)1522-2594(199911)42:5<952::AID-MRM16>3.0.CO;2-S
  8. M. Blaimer, F. Breuer, M. Mueller, R. M. Heidemann, M. A. Griswold, and P. M. Jakob, Top. Magn. Reson. Imag. 15, 223 (2004). https://doi.org/10.1097/01.rmr.0000136558.09801.dd
  9. S. K. Park, C. B. Ahn, D. G. Sim, and H. C. Park, J. Korean Soc. Magn. Reson. Med. 12, 123 (2008).
  10. P. G. Batchelor, D. Atkinson, P. Irarrazaval, D. L. Hill, J. Hajnal, and D. Larkman, Magn. Reson. Med. 54, 1273 (2005). https://doi.org/10.1002/mrm.20656
  11. C. L. Christine, C. R. Jack, R. C. Grimm, P. J. Rossman, J. P. Felmlee, R. L. Ehman, and S. J. Riederer, Magn. Reson. Med. 36, 436 (1996). https://doi.org/10.1002/mrm.1910360316
  12. S. K. Park, Sensitivity Encoding (SENSE) for Parallel MRI. Master's Thesis, Kwangwoon University (2007).
  13. J. F. Glockner, H. H. Hu, D. W. Stanley, L. Angelos, and K. King, Radiographics 25, 1279 (2005). https://doi.org/10.1148/rg.255045202
  14. M. Weiger, K. P. Pruessmann, and P. Boesiger, Magnetic Resonance in Medicine 43, 177 (2000). https://doi.org/10.1002/(SICI)1522-2594(200002)43:2<177::AID-MRM3>3.0.CO;2-1
  15. D. K. Sodickson and W. J. Manning, Magnetic Resonance in Medicine 38, 591 (1999).
  16. K. P. Pruessmann, M. Weiger, P. Bornert, and P. Boesiger, Magnetic Resonance in Medicine 46, 638 (2001). https://doi.org/10.1002/mrm.1241
  17. M. H. Park, J. W. Lee, K. W. Lee, C. W. Ryu, and G. H. Jahng, J. Korean. Soc. Magn. Reson. Med. 13, 161 (2009).