National Institutes of Health (NIH) researchers have combined two multiplexing techniques to shrink the time required to complete whole brain functional MRI (fMRI) scans from 2.5 seconds to roughly .5 seconds, according to a study published in the December issue of PLoS ONE.
As part of the NIH Human Connectome Project, which aims in part to develop quicker and accurate whole brain imaging, the researchers combined two forms of echo planar imaging (EPI) multiplexing on fMRI: temporal multiplexing and spatial multiplexing. "This resulted in an unprecedented reduction in EPI scan time for whole brain fMRI performed at 3 Tesla, permitting TRs [repetition times] of 400 ms and 800 ms compared to a more conventional 2.5 sec TR, and 2–4 times reductions in scan time for HARDI [high-angular-resolution diffusion imaging] imaging of neuronal fibertracks," wrote David A. Feinberg, of Advanced MRI Technologies in Sebastopol, Calif., and co-authors.
According to Feinberg and colleagues, the new technique reduced the 60-slice 3D scan time without significantly sacrificing spatial resolution, while gaining functional sensitivity. Rapid scanning of the brain is important because of the dynamic character of the brain. Moreover, because the improvement is a matter of technique, the reduced scanning time and improved temporal resolution can be achieved on most MRI scanners.
The authors concluded that their "methodology can be used for expanding and enriching the functional and anatomic information obtained from MRI. Further, the reduced scan times may help the clinical acceptance and translation of functional MRI protocols and HARDI neuronal fiber track imaging."