Signal-to-noise ratio and signal-to-noise efficiency in SMASH imaging

Citation
Dk. Sodickson et al., Signal-to-noise ratio and signal-to-noise efficiency in SMASH imaging, MAGN RES M, 41(5), 1999, pp. 1009-1022
Citations number
17
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
Journal title
MAGNETIC RESONANCE IN MEDICINE
ISSN journal
07403194 → ACNP
Volume
41
Issue
5
Year of publication
1999
Pages
1009 - 1022
Database
ISI
SICI code
0740-3194(199905)41:5<1009:SRASEI>2.0.ZU;2-T
Abstract
A general theory of signal-to-noise ratio (SNR) in simultaneous acquisition of spatial harmonics (SMASH) imaging is presented, and the predictions of the theory are verified in imaging experiments and in numerical simulations . In a SMASH image, multiple lines of k-space are generated simultaneously through combinations of magnetic resonance signals in a radiofrequency coil array. Here, effects of noise correlations between array elements as well as new correlations introduced by the SMASH reconstruction procedure are as sessed. SNR and SNR efficiency in SMASH images are compared with results us ing traditional array combination strategies. Under optimized conditions, S MASH achieves the same average SNR efficiency as ideal pixel-by-pixel array combinations, while allowing imaging to proceed at otherwise unattainable speeds. The k-space nature of SMASH reconstructions can lead to oscillatory spatial variations in noise standard deviation, which can produce local en hancements of SNR in particular regions. Magn Reson Med 41:1009-1022, 1999. (C) 1999 Wiley-Liss, Inc.