Article of the Month, January 2019 (Mezer's lab)

The effect of motion correction interpolation on quantitative T1 mapping with MRI

Authors:     Amitay Nachmani, Roey Schurr, Leo Joskowicz, Aviv Mezer   

Published in Medical Image Analysis Volume 52, February 2019, Pages 119-127

Quantitative magnetic resonance imaging (qMRI) is a technique for mapping biophysical properties of the underlying tissue. Any qMRI method requires acquiring several MR images with different contrasts. Due to subject motion, these MR images are not spatially aligned, and it is necessary to register the images to a common reference frame. Yet this involves interpolation and resampling, which can introduce artifacts into the interpolated data. These artifacts could have unfavorable effects on the accuracy of the estimated tissue's physical properties.

The goal of this work was to quantify the error of interpolation and resampling on T1-weighted images and study its effects on the quantitative mapping of the longitudinal relaxation time (T1). Using simulations based on real data, we found that the error is a function of the image contrast and of the translation and rotation of the image. Furthermore, we found that the error in the T1-weighted images has a substantial effect on the T1 estimation, of the order of 10% of the signal in the brain's gray and white matter. Our result suggest that minimizing the registration error can enable more accurate in vivo modeling of brain microstructure.