A pre-operative CT and non-contrast-enhanced C-arm CT registration framework for trans-catheter aortic valve implantation

• A fully automatic image registration framework for pre-operative CT and non-contrast-enhanced C-arm CT.
• Increasing the rigid-body registration success rate by introducing a more robust initial point.
• Increasing the deformable registration accuracy by incorporating anatomical and structural information.
• Efficient implementation that significantly reduces the processing time.
• Tested on more than 20 data sets, both simulated and real data, the proposed method is statistically significantly better than the state-of-the-art methods.

Contrast-enhanced C-arm CT is routinely used for intra-operative guidance during the trans-catheter aortic valve implantation (TAVI); however, the requirement for contrast agent injection is not preferable, especially for patients with renal insufficiencies. To address this problem, we present a novel framework for fully automatic registration of pre-operative CT and non-contrast-enhanced C-arm CT. The proposed framework provides an improved workflow and minimizes the usage of contrast agent in the TAVI procedure. Our framework consists of three steps: coarse rigid-body alignment, anatomical knowledge-based prior deformation field generation, and fine deformable registration. We validated the proposed framework on 20 real patient data sets. Based on the 20 data sets, the mesh-to-mesh errors at the aortic root from different methods are measured. Our proposed method significantly outperforms the other state-of-the-art methods. Specifically, we achieve the registration accuracy at 1.76 ± 0.43 mm which is clinically plausible. Quantitative evaluation on real non-contrast enhanced C-arm CT data sets confirms the applicability in the clinical usage. The proposed heart registration method is generic and hence can be easily applied to other cardiac applications.