POLYCORE: Polygon-based contour refinement for improved Intravascular Ultrasound Segmentation

Kit Mills Bransby1, Retesh Bajaj2, Anantharaman Ramasamy2

  • 1School of Electronic Engineering and Computer Science, Queen Mary University of London, UK; Digital Environment Research Institute, Queen Mary University of London, UK.

PubMed

Insights

We developed POLYCORE, a novel method for coronary vessel wall segmentation in intravascular ultrasound. It improves accuracy in challenging regions with artifacts, outperforming existing techniques for better coronary intervention guidance.

Area of Science:

  • Medical Imaging
  • Artificial Intelligence
  • Cardiovascular Interventions

Background:

  • Accurate segmentation of the coronary vessel wall in intravascular ultrasound (IVUS) is crucial for guiding interventions.
  • Existing dense-based neural networks struggle with image artifacts and shadowed regions, leading to anatomically implausible contours.
  • Challenges include calcified plaque, guide wires, and side branches that obscure vessel structures.

Purpose of the Study:

  • To introduce a novel methodology, Polygon-based Contour Refiner (POLYCORE), to improve coronary vessel wall segmentation.
  • To address topological errors and over-smoothing issues in current dense-based and polygon segmentation networks.
  • To enhance the learning of anatomically rational contours in challenging IVUS imaging scenarios.

Main Methods:

  • Developed POLYCORE, a novel methodology employing a relational inductive bias through higher-order connections between vertices.
  • Introduced a vector field refinement module to iteratively add pixel-level detail and remedy over-smoothing.
  • Enhanced the approach with augmented polygon aggregation, proving more effective than standard test-time augmentation.

Main Results:

  • Achieved state-of-the-art results on two diverse datasets for coronary vessel wall segmentation.
  • Demonstrated significant improvements in segmenting the lumen structure.
  • Showed particular efficacy in topologically challenging regions affected by shadow artifacts.

Conclusions:

  • POLYCORE effectively addresses topological errors and over-smoothing in coronary vessel segmentation.
  • The method enhances segmentation accuracy, especially in difficult imaging conditions.
  • POLYCORE offers a promising advancement for guiding coronary interventions through improved IVUS analysis.

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