We are interested in developing 3D neuroanatomical sequences that can prospectively account for head motion during the scan, making it possible to acquire high-quality brain images even when subjects cannot stay still. To do this, we insert high-speed EPI navigator "sub-sequences" called into the longer anatomical sequences. These EPI volumes are reconstructed and registered in less than 200 ms, and the imaging coordinates are updated so that the anatomical acquisition is always tracking the subject's head.
Additionally, we can use the estimated motion of the subject to guess which segments of the anatomical scan were likely corrupted by motion; these sub-segments are then replayed at the end of the scan to acquire a motion-free set of measurements in consistent coordinates, which can then be reconstructed into a coherent volume. This system is being used by neuropsychologists and clinically to image unsedated children and adults with neurological disorders. (more info)
Several morphometry MR scanning protocols have been developed on Siemens 1.5T and 3T scanners to be used with the FreeSurfer brain mapping software. The MPRAGE protocol is a basic acquisition protocol developed for brain morphometry studies, especially those where the main focus is cortical thickness. The FLASH protocol was developed for morphometry studies as well, and is ideal for whole-brain segmentation where all brain structures are to be labeled by FreeSurfer. The bandwidth-matched protocol was developed for multispectral morphometry studies, and solves the differential distortion problem which allows voxels to match across images of differing contrasts. (more info)