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http://dx.doi.org/10.4283/JMAG.2013.18.4.422

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)

Publication Information

Journal of Magnetics / v.18, no.4, 2013 , pp. 422-427 More about this Journal

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.

Keywords

reference scan; NEX; SNR; SENSE artifact;

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