3D CBCT Challenge 2024: Improved Cone Beam CT Reconstruction using SwinIR-Based Sinogram and Image Enhancement

In this paper, we present our approach to the 3D CBCT Challenge 2024, a part of ICASSP SP Grand Challenges 2024. Improvement in Cone Beam Computed Tomography (CBCT) reconstruction has been achieved by integrating Swin Image Restoration (SwinIR) based sinogram and image enhancement modules. The proposed methodology uses Nesterov Accelerated Gradient Descent (NAG) to solve the least squares (NAG-LS) problem in CT image reconstruction. The integration of sinogram and image enhancement modules aims to enhance image clarity and preserve fine details, offering a promising solution for both low dose and clinical dose CBCT reconstruction. The averaged mean squared error (MSE) over the validation dataset has decreased significantly, in the case of low dose by one-fifth and clinical dose by one-tenth. Our solution is one of the top 5 approaches in this challenge.

A Robust Pipeline for Classification and Detection of Bleeding Frames in Wireless Capsule Endoscopy using Swin Transformer and RT-DETR

In this paper, we present our approach to the Auto WCEBleedGen Challenge V2 2024. Our solution combines the Swin Transformer for the initial classification of bleeding frames and RT-DETR for further detection of bleeding in Wireless Capsule Endoscopy (WCE), enhanced by a series of image preprocessing steps. These steps include converting images to Lab colour space, applying Contrast Limited Adaptive Histogram Equalization (CLAHE) for better contrast, and using Gaussian blur to suppress artefacts. The Swin Transformer utilizes a tiered architecture with shifted windows to efficiently manage self-attention calculations, focusing on local windows while enabling cross-window interactions. RT-DETR features an efficient hybrid encoder for fast processing of multi-scale features and an uncertainty-minimal query selection for enhanced accuracy. The class activation maps by Ablation-CAM are plausible to the model's decisions. On the validation set, this approach achieves a classification accuracy of 98.5% (best among the other state-of-the-art models) compared to 91.7% without any pre-processing and an $\text{AP}_{50}$ of 66.7% compared to 65.0% with state-of-the-art YOLOv8. On the test set, this approach achieves a classification accuracy and F1 score of 87.0% and 89.0% respectively.