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High‐frequency subband compressed sensing MRI using quadruplet sampling
Author(s) -
Sung Kyunghyun,
Hargreaves Brian A.
Publication year - 2013
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24592
Subject(s) - undersampling , compressed sensing , computer science , wavelet , frequency domain , spatial frequency , artificial intelligence , sampling (signal processing) , pattern recognition (psychology) , algorithm , signal (programming language) , iterative reconstruction , image resolution , fourier transform , computer vision , mathematics , physics , optics , mathematical analysis , filter (signal processing) , programming language
Purpose To present and validate a new method that formalizes a direct link between k‐space and wavelet domains to apply separate undersampling and reconstruction for high‐ and low‐spatial‐frequency k‐space data. Theory and Methods High‐ and low‐spatial‐frequency regions are defined in k‐space based on the separation of wavelet subbands, and the conventional compressed sensing problem is transformed into one of localized k‐space estimation. To better exploit wavelet‐domain sparsity, compressed sensing can be used for high‐spatial‐frequency regions, whereas parallel imaging can be used for low‐spatial‐frequency regions. Fourier undersampling is also customized to better accommodate each reconstruction method: random undersampling for compressed sensing and regular undersampling for parallel imaging. Results Examples using the proposed method demonstrate successful reconstruction of both low‐spatial‐frequency content and fine structures in high‐resolution three‐dimensional breast imaging with a net acceleration of 11–12. Conclusion The proposed method improves the reconstruction accuracy of high‐spatial‐frequency signal content and avoids incoherent artifacts in low‐spatial‐frequency regions. This new formulation also reduces the reconstruction time due to the smaller problem size. Magn Reson Med 70:1306–1318, 2013. © 2012 Wiley Periodicals, Inc.