High Angular Resolution Diffusion Imaging (HARDI) is one of the primary imaging technologies to be employed for the Human Connectome Project. This approach benefits from high gradient amplitudes for diffusion weighting, which shorten the echo time (TE) and consequently increase the signal-to-noise ratio (SNR).
From the inception of the project, the Connectome Skyra was specially configured for HARDI data acquisition. A new design for the Skyra was agreed upon by the WashU-Minn HCP consortium and Siemens, using modified gradient amplifiers to drive a custom gradient set based on the SC72 gradient. The SC72 gradient is currently employed as a product on the latest Siemens 7 Tesla systems.
The first step in the Skyra’s evolution was successfully completed in July 2011. The SC72 gradient set, redesigned for the Skyra magnet, was installed in the Connectome Skyra. Siemens also implemented new auxiliary parts compatible with the new gradient: new magnet covers, a redesigned patient table, and radiofrequency (RF) coil for transmission. At present, the Connectome Skyra can achieve 70 mT/m maximum gradient strength, as opposed to the standard system’s 40 mT/m. In the next month, we expect to enable a maximum of 100 mT/m gradient strength with additional gradient amplifier modification.
The Connectome Skyra, currently located at the University of Minnesota’s Center for Magnetic Resonance Research, has also been approved for human subject testing by the University of Minnesota’s institutional review board, keeping our work on OT1 and OT2 on schedule.
- HCP Project Components: Acquisition of HARDI Diffusion Data.
- HCP Project News: The Skyra has Landed!
Correction (8/9/2011): This article originally reported an expected maximum gradient strength of 110 mT/m. Siemens tells us that while 110 mT/m is theoretically possible, the highest that we should expect is 100 mT/m.