A token-mixer architecture for CAD-RADS classification of coronary stenosis on multiplanar reconstruction CT images

Marco Penso1, Sara Moccia2, Enrico G Caiani3

  • 1Cardiovascular Imaging Department, Centro Cardiologico Monzino IRCCS, Milan, Italy; Department of Electronics, Information and Biomedical Engineering, Politecnico di Milano, Milan, Italy.

Insights

A deep learning algorithm using ConvMixer accurately classifies coronary artery stenosis from CCTA images. This tool aids in precise stenosis evaluation, potentially reducing variability in clinical decision-making for coronary artery disease.

Area of Science:

  • Cardiovascular Imaging
  • Artificial Intelligence in Medicine
  • Medical Image Analysis

Background:

  • Accurate assessment of coronary artery stenosis is crucial for managing suspected Coronary Artery Disease (CAD).
  • Coronary Computed Tomography Angiography (CCTA) is a key imaging modality for evaluating coronary stenosis.
  • Standardized reporting systems like CAD-RADS improve consistency in stenosis classification.

Purpose of the Study:

  • To develop and evaluate an automatic deep learning algorithm for classifying coronary stenosis severity.
  • To apply the algorithm to multiplanar reconstruction images from CCTA scans.
  • To classify lesions according to the Coronary Artery Disease Reporting and Data System (CAD-RADS).

Main Methods:

  • A retrospective study included 288 patients with suspected CAD who underwent CCTA.
  • A token-mixer architecture (ConvMixer) was employed to model long-range semantic information in coronary artery images.
  • ConvMixer utilizes a patch embedding layer and convolutional blocks to learn pixel dependencies; performance was assessed using Grad-CAM.

Main Results:

  • The ConvMixer algorithm achieved 87% accuracy and 90% sensitivity in classifying significant coronary artery stenosis (≥50% luminal narrowing).
  • For CAD-RADS 0 vs. 1-2 vs. 3-4 vs. 5 classification, ConvMixer demonstrated 72% accuracy and 75% sensitivity.
  • ConvMixer showed a superior performance-complexity trade-off compared to pyramid-shaped convolutional neural networks.

Conclusions:

  • The developed deep learning algorithm shows promise for automated coronary artery stenosis evaluation.
  • This tool may serve as decision support for clinicians, potentially reducing interobserver variability.
  • The findings suggest a role for AI in improving the consistency and precision of CAD assessment.
Abstract