23 November 2021: Recovery mode

Our quartley updates on OSIPI Milestones and Deliverables for November 2021 are listed below. Also worthy to note, we just passed both the ISMRM annual meeting and Perfusion Workshop abstract submissions where six OSIPI abstracts were submitted (TF 2.2, 2.3, 4.1, 4.2, 6.1, and 6.2) – congratulations team! Also check out the OSIPI resources page where all key results are summarized and maintained.

Task force 1.1 (ASL software inventory) prepared scoring rules for the pipeline comparison and contacted all pipeline developers from ASL pipeline inventory for support and help. People willing to actively participate in the comparison and co-author the comparison publication should contact Jan Petr until the end of this month (30Nov).

Task force 1.2 (DCE/DSC software inventory) has distributed an online survey to engage potential DC software reviewers. Willing volunteers will be provided with a DSC or DCE digital reference object (DRO) and will evaluate the software tool using an online review form that covers both quantitative measures and qualitative assessment. The deadline for DC software reviews is February 2022 (Milestone 6).

Task force 2.2 (ASL code repository) continue to gather and test ASL processing code. Currently, they received source code from 5 different groups with an anticipated contribution from 2 additional groups. Some of the functionalities have been tested and documented here. The remaining source code is under review by the team and the functionalities are being separated and documented..

Task force 2.3 (DCE/DSC code repository) has now achieved Milestone #5 (lead: Michael Berks), publishing an outline proposal for a standardised OSIPI perfusion analysis library in Python, which we hope to begin developing from 2022. We have continued to implement testing of contributed code snippets, including those for signal-to-concentration conversion, perfusion parameter estimation and arterial input functions. Our present focus is on completing this testing (Deliverable #1) and on visualising the performance of code contributions (Milestone #6, lead: Zaki Ahmed). The taskforce has submitted abstracts to the forthcoming International and Benelux Chapter ISMRM meetings.

Task force 3.1 (DROs and phantoms) has created a new test-site for OSIPI Libraries that includes updates for TF3.1 including (1) Phantom Contributions Inventory and (2) Phantom Literature. The site is generated using JSON format to be consistent with the ISMRM MR-Hub hosted on github. The literature entries were generated using the cloud-based reference manager Zotero.org to facilitate citation exporting and re-formatting by external users. The contribution inventory test site can be found here. The taskforce is also working with the ISMRM Reproducible Research Study Group to come up with common recommendations for sharing of code and DROs.

Task force 3.2 (Data sharing) has been having monthly calls attended by Andrey, Greg, and Annette from the task force. Currently, discussing related challenges to sharing preclinical data set (lead: Annette). Greg has been working on an invited presentation for the upcoming MRI Together workshop sponsored by the ESMRMB.

Task force 4.1 (ASL lexicon) has shared the draft of “Arterial Spin Labeling Perfusion Imaging and Analysis Lexicon and Reporting Recommendations (v0.1)“. with the ISMRM Perfusion Study Group Members for feedback. Please feel free to leave your suggestions/comments directly in Google Docs from this link. Also, please let us know if you agree with the drafted categories for each parameter of the reporting recommendation by completing this survey.

Task force 4.2 (DCE/DSC lexicon) has written clean versions of the sections on perfusion models, perfusion identities and large parts of the general purpose processes and perfusion-specific processes. We also applied the lexicon to generate an example pipeline representing a typical DCE analysis workflow. We met up with the TF 4.1 to harmonize the lexicon efforts for DCE/DSC and ASL. There we identified that we should provide common naming for the same physiological parameters or at least specify synonyms. We also decided to publish our results in an analogous way and will stay in contact about the publication style between the two task forces. We submitted an abstract on our progress to the ISMRM 2022.

Task force 6.1 (ASL challenges) has received 7 registration and 3 dadta submissions since their ASL challenge opened in February 2021. Using these submitted sites, preliminary results were submitted to the recent ISMRM 2022 conference. Initial results showed the use of different tools to analyze ASL data by the community which led to variability in the CBF estimates from the challenge entries as well as errors when compared to the ground-truth maps. The ASL challenge has a new deadline and will be closed for new entries after December 16th.

Task force 6.2 (DCE/DSC challenges) received multiple challenge results before the ISMRM abstract submission deadline this month. Taskforce 6.2 members performed an analysis for preliminary ranking of the received submissions based on OSIPI-score. The initial data shows variability in accuracy, repeatability, and reproducibility of the analysis pipelines leading to different Ktrans estimations. We appreciate the courage of all participants for coming forward to submit their results. We are still accepting more submissions and encourage everyone in the field of DCE-MRI quantification to join us in this benchmarking effort!

Best wishes,

The OSIPI Executive & Management Board