Reducing the unwanted draining vein BOLD contribution in fMRI with statistical post-processing methods. Neuroimage 2007 Aug 01;37(1):177-88
Date
06/15/2007Pubmed ID
17560130DOI
10.1016/j.neuroimage.2007.03.075Scopus ID
2-s2.0-34447562908 (requires institutional sign-in at Scopus site) 39 CitationsAbstract
Recent BOLD fMRI data analysis methods show promise in reducing contributions from draining veins. The phase regressor method developed by [Menon, R.S., 2002. Post-acquisition suppression of large-vessel BOLD signals in high-resolution fMRI. Magn. Reson. Med., 47, 1-9] creates phase and magnitude images, regresses magnitude as a function of phase, and subtracts phase-estimated magnitudes from the observed magnitudes. The corrected magnitude images are used to compute cortical activations. The complex constant phase method, developed by [Rowe, D.B., Logan, B.R., 2004. A complex way to compute fMRI activation. NeuroImage, 23, 1078-1092], uses complex-valued reconstructed images and a nonlinear regressor model to compute magnitude cortical activations assuming temporally constant phase. In both methods, the usage of the phase information is claimed to bias against voxels with task-related phase changes caused by some draining veins. The behavior of the statistical methods in data with several task-related magnitude and phase changes is compared. The power of the statistical methods for determining voxels with specific task-related magnitude and phase change combinations are determined in ideal simulated data. The phase regressor and complex constant phase activation determination techniques are examined to characterize the responses of the models to select task-related phase and magnitude change combinations in representative simulated time series. Possible draining veins in human preliminary data are discussed and analyzed with the models and the current challenges which prevent these methods from being reliably implemented are discussed.
Author List
Nencka AS, Rowe DBAuthor
Andrew S. Nencka PhD Director, Associate Professor in the Radiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AlgorithmsArtifacts
Cerebral Angiography
Cerebral Cortex
Cerebral Veins
Evoked Potentials, Motor
Fourier Analysis
Humans
Image Processing, Computer-Assisted
Magnetic Resonance Imaging
Models, Statistical
Motor Activity
Motor Cortex
Nonlinear Dynamics
Oxygen
Software