Title
Blind recovery of biochemical markers of brain cancer in MRSI
Abstract
We present an algorithm for blindly recovering constituent source spectra from magnetic resonance spectroscopic imaging (MRSI) of human brain. The algorithm is based on the non-negative matrix factorization (NMF) algorithm,(1,2) extending it to include a constraint on the positivity of the amplitudes of the recovered spectra and mixing matrices. This positivity constraint enables recovery of physically meaningful spectra even in the presence of noise that causes a significant number of the observation amplitudes to be negative. The algorithm, which we call constrained non-negative matrix factorization (cNMF), does not enforce independence or sparsity, though it recovers sparse sources quite well. It can be viewed as a maximum likelihood approach for finding basis vectors in a bounded subspace. In this case the optimal basis vectors are the ones that envelope the observed data with a minimum deviation from the boundaries. We incorporate the cNMF algorithm into a hierarchical decomposition framework, showing that it can be used to recover tissue-specific spectra, e.g., spectra indicative of malignant tumor. We demonstrate the hierarchical procedure on H-1 long echo time (TE) brain absorption spectra and conclude that the computational efficiency of the cNMF algorithm makes it well-suited for use in diagnostic work-up.
Year
DOI
Venue
2004
10.1117/12.534652
Proceedings of SPIE
Keywords
Field
DocType
non-negative matrix factorization (NMF),blind source separation (BSS),magnetic resonance spectroscopic,imaging (MRSI),hierarchical decomposition,brain cancer
Subspace topology,Matrix (mathematics),Matrix decomposition,Algorithm,Speech recognition,Non-negative matrix factorization,Minimum deviation,Magnetic resonance spectroscopic imaging,Basis (linear algebra),Mathematics,Bounded function
Conference
Volume
ISSN
Citations 
5370
0277-786X
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Shuyan Du1455.28
Xiangling Mao2404.73
Dikoma C. Shungu3404.73
Paul Sajda465189.86