A novel approach to accurate 3D high resolution and high SNR fetal brain imaging

Fetal brain imaging by MRI is attracting increasing interest because it offers excellent contrast and anatomical details. However, unpredictable fetal motion has led to widespread use of single shot techniques to freeze fetal motion. The conventional result is series of images which have an uncertain spatial relationship and cannot be reconstructed into a coherent 3D volume. We present a novel methodology to reconstruct 3D images of fetal brains in-utero with sub-millimeter isotropic high resolution and high SNR. After continuous scanning to acquire a repeated series of parallel slices, image registration is used to realign the images to correct for fetal motion. Compounding of multiple images yields high SNR even with imaging parameters chosen to provide high resolution at the expense of SNR in individual images. The method has been tested on four normal fetuses imaged at 1.5 T and validated on both adult and neonatal simulated data. In all cases detailed 3D brain images with anatomical details clearly visible in all planes were successfully reconstructed