Limperopoulos, C. | bioRxiv Science

bioRxiv2017

Study on Linear Combination of Long Memory Processes Corrupted by Additive Noises for fMRI Time Series Analysis

Estimating the long memory parameter of the fMRI time series enables us to understand the fractal behavior of neural activity of the brain through fMRI time series. However, the existence of white noise and physiological noise compounds which also have fractal properties prevent us from making the estimation precise. As basic strategies to overcome noises, we address how to estimate the long memory parameter in the presence of additive noises, and how to estimate the long memory parameters of linearly combined long memory processes.

biophysics↗

bioRxiv2017

Inter-slice motion correction using spatiotemporal interpolation for functional magnetic resonance imaging of the moving fetus

Fetal motion continues to be one of the major artifacts in in-utero functional MRI; interestingly few methods have been developed to address fetal motion correction. In this study, we propose a robust method for motion correction in fetal fMRI by which both inter-slice and inter-volume motion artifacts are jointly corrected. To accomplish this, an original volume is temporally split into odd and even slices, and then voxel intensities are spatially and temporally interpolated in the process of image registration. Our experimental data demonstrate that our method was more effective in correcting fetal motion artifact compared to traditional motion correction methods.

bioengineering↗