Topology-Aware Anatomical Segmentation of the Circle of Willis for CTA and MRA


Background 🏥

The Circle of Willis (CoW) is an important anastomotic network of arteries connecting the anterior and posterior circulations of the brain, as well as the left and right cerebral hemispheres [1]. Due to its centrality, the CoW is commonly involved in pathologies like aneurysms and stroke. Clinically, the vascular architecture of the CoW is believed to impact the occurrence and severity of stroke [2, 3]. An accurate characterization of the CoW is therefore of great clinical relevance.

However, clinicians have articulated an unmet demand for efficient software tools to analyze and compare the angio-architecture of the CoW. Assessing the anatomy and vascular components of the CoW from medical angiography images is still an expert task and time-consuming. Furthermore, the CoW naturally has many anatomical variants. It is estimated that only around half of our population has a complete CoW [4, 5]. It is not an exception to see the CoW anatomies vary markedly from person to person. An automated and personalized CoW vascular characterization will be of significant interest to both the clinical and the research communities.

Here, we propose the first public challenge on CoW angio-architecture extraction and brain vessel segment annotation on two common angiographic imaging modalities, namely magnetic resonance angiography (MRA) and computed tomography angiography (CTA). We identify a gap in good quality anatomical annotations, newer imaging datasets, and datasets of multiple modalities. By releasing a public dataset covering both CTA and MRA with careful annotations on the vasculature, our challenge hopes to foster research and better benchmark comparisons on the CoW vascular segmentation results.

🎥 Videos of Annotated CoW

Example of a paired CTA (left) and MRA (right) with CoW annotations.


Objective 🥕

The aim of the challenge is to extract the CoW angio-architecture from 3D angiographic imaging by segmentation of the vessel components. There are two sub-tasks: binary segmentation of CoW vessels, and multi-class CoW anatomical segmentation. We release a new dataset of joint-modalities, CTA and MRA of the same patient cohort, both with annotations of the anatomy of CoW. Our challenge has two tracks for the same segmentation task, namely CTA track and MRA track. We made use of the clinical information from both modalities during our annotation. And participants can pick whichever modality they want, both CTA and MRA, and choose to tackle the task for either modality. (See "2 Tracks 2 Tasks" page for more info.)

A technical emphasis of this challenge is on topology-aware segmentation. The extracted vessels should retain the topology of the underlying anatomy. We especially hope to raise awareness on the importance of evaluating performance beyond pixel-based or volumetric metrics. In particular, we will evaluate the segmentation performance on topology-based metrics. The challenge aims for vascular characterizations that capture the underlying topology and geometric variability of the CoW. (See "Assessment" page for more info.)


Impact 🐄

CoW Extraction and Characterization Tool

An automated CoW characterization on vessel anatomical labelings and topological properties can lead to many interesting downstream tasks and applications!

  • Personalized neurovascular disease management
  • Screening for CoW variants
  • Reveal demographic geometric risk factors for vascular pathologies
Data Value [Data, Annotations]

Our challenge also helps to fill a gap in good quality CoW anatomical annotations, newer imaging datasets, and datasets of dual modalities.

  • Public dataset for paired CTA and MRA
  • Verified annotations on 3D vasculature
  • Detailed anatomy labeled

Based on the clinical impact, data value, and research potential, we look forward to organizing this challenge (and its repeats) and welcoming submissions!


Timeline 📅


Cite Us!

👉 📰 Please cite our summary paper if you use our dataset in your research or publications: https://arxiv.org/abs/2312.17670

  @misc{topcowchallenge,
        title={Benchmarking the CoW with the TopCoW Challenge: Topology-Aware Anatomical Segmentation of the Circle of Willis for CTA and MRA}, 
        author={Kaiyuan Yang and Fabio Musio and Yihui Ma and Norman Juchler and Johannes C. Paetzold and Rami Al-Maskari and Luciano Höher and Hongwei Bran Li and Ibrahim Ethem Hamamci and Anjany Sekuboyina and Suprosanna Shit and Houjing Huang and Chinmay Prabhakar and Ezequiel de la Rosa and Diana Waldmannstetter and Florian Kofler and Fernando Navarro and Martin Menten and Ivan Ezhov and Daniel Rueckert and Iris Vos and Ynte Ruigrok and Birgitta Velthuis and Hugo Kuijf and Julien Hämmerli and Catherine Wurster and Philippe Bijlenga and Laura Westphal and Jeroen Bisschop and Elisa Colombo and Hakim Baazaoui and Andrew Makmur and James Hallinan and Bene Wiestler and Jan S. Kirschke and Roland Wiest and Emmanuel Montagnon and Laurent Letourneau-Guillon and Adrian Galdran and Francesco Galati and Daniele Falcetta and Maria A. Zuluaga and Chaolong Lin and Haoran Zhao and Zehan Zhang and Sinyoung Ra and Jongyun Hwang and Hyunjin Park and Junqiang Chen and Marek Wodzinski and Henning Müller and Pengcheng Shi and Wei Liu and Ting Ma and Cansu Yalçin and Rachika E. Hamadache and Joaquim Salvi and Xavier Llado and Uma Maria Lal-Trehan Estrada and Valeriia Abramova and Luca Giancardo and Arnau Oliver and Jialu Liu and Haibin Huang and Yue Cui and Zehang Lin and Yusheng Liu and Shunzhi Zhu and Tatsat R. Patel and Vincent M. Tutino and Maysam Orouskhani and Huayu Wang and Mahmud Mossa-Basha and Chengcheng Zhu and Maximilian R. Rokuss and Yannick Kirchhoff and Nico Disch and Julius Holzschuh and Fabian Isensee and Klaus Maier-Hein and Yuki Sato and Sven Hirsch and Susanne Wegener and Bjoern Menze},
        year={2024},
        eprint={2312.17670},
        archivePrefix={arXiv},
        primaryClass={cs.CV}
  }
GitHub

Please visit our GitHub for repos and documentations on:

Forum

We have a forum to post your questions! Link

CoWBenchmark Event

🤝 We collaborate with the "CiRcle Of Willis INtracranial Artery Classification and Quantification" CROWN Challenge!
A subset of our data will be shared, jointly annotated and evaluated by both challenges.
Please check out our joint-event website for more updates :)


References:

  • [1] AG, Osborn. "Osborn's brain: imaging, pathology, and anatomy." Salt Lake City, Utah: Amirsys (2013): 932-940.
  • [2] Chuang, Yu-Ming, et al. "Configuration of the circle of Willis is associated with less symptomatic intracerebral hemorrhage in ischemic stroke patients treated with intravenous thrombolysis." Journal of critical care 28.2 (2013): 166-172.
  • [3] van Seeters, Tom, et al. "Completeness of the circle of Willis and risk of ischemic stroke in patients without cerebrovascular disease." Neuroradiology 57.12 (2015): 1247-1251.
  • [4] Krabbe-Hartkamp, Monique J., et al. "Circle of Willis: morphologic variation on three-dimensional time-of-flight MR angiograms." Radiology 207.1 (1998): 103-111.
  • [5] Iqbal, S. "A comprehensive study of the anatomical variations of the circle of willis in adult human brains." Journal of clinical and diagnostic research: JCDR 7.11 (2013): 2423.
  • The cow image used in the banner and logo is Image by winterseitler from Pixabay