Exploratory analysis of Type B Aortic Dissection (TBAD) segmentation in 2D CTA images using various kernels

Type-B Aortic Dissection is a rare but fatal cardiovascular disease characterized by a tear in the inner layer of the aorta, affecting 3.5 per 100,000 individuals annually. In this work, we explore the feasibility of leveraging two-dimensional Convolutional Neural Network (CNN) models to perform accurate slice-by-slice segmentation of true lumen, false lumen and false lumen thrombus in Computed Tomography Angiography images. The study performed an exploratory analysis of three 2D U-Net models: the baseline 2D U-Net, a variant of U-Net with atrous convolutions, and a U-Net with a custom layer featuring a position-oriented, partially shared weighting scheme kernel. These models were trained and benchmarked against a state-of-the-art baseline 3D U-Net model. Overall, our U-Net with the VGG19 encoder architecture achieved the best performance score among all other models, with a mean Dice score of 80.48% and an IoU score of 72.93%. The segmentation results were also compared with the Segment Anything Model (SAM) and the UniverSeg models. Our findings indicate that our 2D U-Net models excel in false lumen and true lumen segmentation accuracy while achieving lower false lumen thrombus segmentation accuracy compared to the state-of-the-art 3D U-Net model. The study findings highlight the complexities involved in developing segmentation models, especially for cardiovascular medical images, and emphasize the importance of developing lightweight models for real-time decision-making to improve overall patient care.