A Novel Multi-Echo FMRI Weighting Strategy Using Principal Component Analysis for BOLD Contrast Sensitivity Enhancement

Mark Chiew^1,2, Simon James Graham^1,2

The use of multi-echo imaging techniques for contrast enhancement in BOLD fMRI is gaining momentum, particularly in real-time fMRI applications. A novel method is presented for combining multi-echo signals in weighted summation using principal component analysis (PCA) derived weights. The method is evaluated on human volunteers performing a simple motor task at 1.5 T, and is compared to other reported weighting schemes. The data driven PCA weighting method is demonstrated to produce time-series that achieve high relative contrast-to-noise ratio gain, without requiring additional data collection.