Improved 3D Whole Heart Geometry from Sparse CMR Slices
Yiyang Xu, Hao Xu, Matthew Sinclair, Esther Puyol-Antón, Steven A Niederer, Amedeo Chiribiri, Steven E Williams, Michelle C Williams, Alistair A Young
TL;DR
This work tackles reconstructing accurate 3D whole-heart geometry from sparse CMR slices, a challenge amplified by respiratory motion and limited dense data. It introduces and evaluates six model combinations that fuse Slice Shifting Algorithm (SSA) for motion correction, Spatial Transformer Network (STN) for atlas-based deformation, and Label Transformer Network (LTN) for dense geometry reconstruction, using CT-derived ground truth to generate synthetic CMR data. Key findings show that SSA-LTN achieves the highest Dice and Hausdorff distance performance but can introduce topological errors, STN effectively fixes topology with minimal performance loss, and DSTN further reduces topology errors, with SSA acting as a versatile plug-in. The results offer practical guidance for robust, topology-consistent 3D whole-heart reconstructions from sparse CMR data, enabling non-invasive imaging workflows with improved downstream shape analysis and clinical applicability.
Abstract
Cardiac magnetic resonance (CMR) imaging and computed tomography (CT) are two common non-invasive imaging methods for assessing patients with cardiovascular disease. CMR typically acquires multiple sparse 2D slices, with unavoidable respiratory motion artefacts between slices, whereas CT acquires isotropic dense data but uses ionising radiation. In this study, we explore the combination of Slice Shifting Algorithm (SSA), Spatial Transformer Network (STN), and Label Transformer Network (LTN) to: 1) correct respiratory motion between segmented slices, and 2) transform sparse segmentation data into dense segmentation. All combinations were validated using synthetic motion-corrupted CMR slice segmentation generated from CT in 1699 cases, where the dense CT serves as the ground truth. In 199 testing cases, SSA-LTN achieved the best results for Dice score and Huasdorff distance (94.0% and 4.7 mm respectively, average over 5 labels) but gave topological errors in 8 cases. STN was effective as a plug-in tool for correcting all topological errors with minimal impact on overall performance (93.5% and 5.0 mm respectively). SSA also proves to be a valuable plug-in tool, enhancing performance over both STN-based and LTN-based models. The code for these different combinations is available at https://github.com/XESchong/STACOM2024.
