The need for a harmonized protocol
Recent years have seen increased interest in measuring the subfields of the human hippocampal formation using MRI, with several research groups seeking to develop protocols and methods for delineating subfields in routine clinical resolution MRI data. However, progress in this area has been impeded by the significant amount of disagreement that exists between groups in the anatomical definition of the subfields, the strategies used to group smaller subfields into aggregate anatomical labels, and the rules used to delineate subfield boundaries in MRI data.
Furthermore, protocols designed for labeling different modalities for imaging the hippocampus, such as functional MRI, in vivo structural MRI, postmortem MRI microscopy, or histology, often demand different compromises between anatomical accuracy and repeatability, which leads to diverging protocols between the different communities within neuroimaging and between neuroimaging and neuroanatomy communities.
How to move forward
With the emergence of a harmonized protocol for labeling the hippocampus as a whole (by Frisoni, Jack and colleagues), we believe that the subfield community can come together to develop a similar unified hippocampal subfield segmentation protocol. Indeed, the HSG now has more than 200 members interested in working together to develop a common protocol.
As a first step (see Yushkevich et al., 2015), we quantitatively characterized the differences that existed between leading hippocampal subfield segmentation protocols so that we can move towards reducing them with a harmonized protocol.
Additionally, members of the HSG meet regularly to work towards development of a harmonized protocol, as well as to share recent findings relating to hippocampal subfields. For more information on these working group meetings and to register for upcoming conferences please click here.
Our vision
We provide a more detailed description of our vision in Wisse et al., 2017. In brief, we aim to:
- Bring together researchers with expertise in imaging human hippocampal subfields, as well as neuroanatomists with MTL expertise and computational algorithm developers
- Identify differences in existing subfield segmentation protocols
- Reduce these differences by developing a unified protocol (or protocols) for segmenting human hippocampal subfields and subregions of MTL cortex
- Produce joint publications detailing progress along the way
In addition to the founding members who form a steering committee, this endeavor is only possible by contributions from a large global network of laboratories who conduct high-resolution neuroimaging and conduct either manual, semi-automated or fully automated segmentations of hippocampal subfields.
How do I get involved?
We currently have several active working groups working on specific parts of the harmonization effort. Check their individual pages (found under People) to learn more about them.
To keep up to date with progress and to learn about activities you have a chance to participate in, you can subscribe to our e-mail list or follow us on Twitter.