MGH-USC Human Connectome Project datasets with ultra-high b-value diffusion MRI

Abstract

The MGH-USC CONNECTOM MRI scanner housed at the Massachusetts General Hospital (MGH) is a major hardware innovation of the Human Connectome Project (HCP). The 3T CONNECTOM scanner is capable of producing a magnetic field gradient of up to 300 mT/m strength for in vivo human brain imaging, which greatly shortens the time spent on diffusion encoding, and decreases the signal loss due to T2 decay. To demonstrate the capability of the novel gradient system, data of healthy adult participants were acquired for this MGH-USC Adult Diffusion Dataset (N=35), minimally preprocessed, and shared through the Laboratory of Neuro Imaging Image Data Archive (LONI IDA) and the WU-Minn Connectome Database (ConnectomeDB). Another purpose of sharing the data is to facilitate methodological studies of diffusion MRI (dMRI) analyses utilizing high diffusion contrast, which perhaps is not easily feasible with standard MR gradient system. In addition, acquisition of the MGH-Harvard-USC Lifespan Dataset is currently underway to include 120 healthy participants ranging from 8 to 90 years old, which will also be shared through LONI IDA and ConnectomeDB. Here we describe the efforts of the MGH-USC HCP consortium in acquiring and sharing the ultra-high b-value diffusion MRI data and provide a report on data preprocessing and access. We conclude with a demonstration of the example data, along with results of standard diffusion analyses, including q-ball Orientation Distribution Function (ODF) reconstruction and tractography.

Keywords: Adolescents; Children; Lifespan; Multi-shell HARDI; Older adults; Preprocessing.

Figure 1

Age distribution of the participants of the MGH-USC Adult Diffusion Dataset (N=35).

Figure 2

Gradient direction sets of the MGH-USC Adult Diffusion Dataset

Figure 3

Anatomical scans. An axial plane of the T1w, T2w scans, and the mask used for ear (blue arrow) and face (white arrows) stripping are shown.

Figure 4

DW images at different b-values. Intensity scales were adjusted to better reveal the image contrasts.

Figure 5

q-ball ODF reconstruction of dMRI data with (a) b=1000 s/mm², (b) b=3000 s/mm², (c) b=5000 s/mm², (d) b=10000 s/mm² in the centrum semiovale. For b=5000 and 10000 s/mm², the region circled in yellow (c–d) was zoomed-in and shown in (e–f). The territories of major fiber tracts were labeled in (a): Cing = cingulate; CC = Corpus Callosum; CST = CorticoSpinal Tract; SLF = Superior Longitudinal Fasciculus.

Figure 6

Front view of the fiber tracts reconstructed from dMRI data with different b-values. Streamlines passing by either of the bi-lateral postcentral gyri were selected and shown. For different b-values, the same region in the centrum semiovale was circled in yellow and zoomed-in to reveal the difference.

Figure 7

Feasibility of high b-value dMRI across the lifespan. GQI ODF reconstruction of multi-shell dMRI data in three example subjects from different age cohorts (a–c). Enlarged ventricles in the older adult indicate age-associated brain atrophy (c). Tractography results show major and fine inter-hemispheric white matter bundles in all three cases. Tracts are labeled in (d): FX = Fornix; CC = Corpus Callosum; CB = Cingulate Bundle; AC = Anterior Commissure; OC = Optic Chiasm.