Abstract: (Download poster, 20.6 MB)

The objective is to build a statistically meaningful, MRI-based interactive atlas of the human cerebral sulci that represents an update and large-scale expansion of the atlas by Ono and colleagues (“Ono”; Thieme Medical, New York, 1990). Ono provides several images of sulci from multiple brains to demonstrate common topographic variants and reports the incidence rate of each variant. As such, it has proven useful to clinicians and researchers alike. It is hindered, however, by a small sample size that limits the significance of reported sulcal patterns and incidence. Its physical form also limits the amount of image data that can be displayed and prohibits interactive use. These limitations will be overcome by deriving data from 800+ subjects and by making the atlas available digitally.
The atlas is based on manually labeled structural MRI scans. Cerebral sulci are delineated on a rendering of the WM surface in each scan. Quantitative measures include sulcus position, replication, interruptions, side branching, and connections to other sulci. Position is expressed both in terms of a common reference frame (MNI) and with respect to other sulci. The latter is used to identify common patterns of local sulcal topography. The atlas will be delivered as a part of the neuroanatomical analysis platform, “NeuroMorphoNaut” (NMN), which is freely available from Neuromorphometrics, Inc. NMN allows the exploration, visualization, and measurement of the anatomy of an individual scan in the context of a large database of comprehensively labeled scans along with probabilistic and traditional atlases. Statistics and images of common patterns from the new sulci atlas are interactively available for comparison to each other and to the user’s own data.
Sulci in 20 OASIS scans have been labeled so far. These data have been used to characterize common topographic patterns of variable sulci to improve cortical region of interest (ROI) definitions. For instance, lateral orbital sulcus often serves as boundary for inferior frontal ROIs. los terminates lateral to the anterior horizontal ramus of the lateral sulcus, another common inferior frontal bounding landmark, in just 65% of hemispheres studied to date. These findings have led to heuristics that permit consistent labeling of ROIs in this region. Similar studies of other highly variable sulci are underway.
This interactive digital atlas represents a major upgrade over current resources that will significantly improve our understanding of cerebral sulcal anatomy and its variation. It will serve as a valuable and convenient reference tool for clinicians, anatomists, and the neuroimaging community.