M Wagner*, S Periyasamy, P Laeseke, A Raval, M Speidel, University of Wisconsin - Madison, Madison, WI

• 
  M Wagner

TH-C-201-2 (Thursday, 7/14/2022) 10:00 AM - 11:00 AM [Eastern Time (GMT-4)]

Room 201

Purpose: Continuous-sweep limited angle (CLA) fluoroscopy is a method of real-time 3D reconstruction and tracking of interventional devices based on 2D fluoroscopic images acquired during limited-angle back-and-forth rotation of a C-arm. CLA has been recently investigated for percutaneous and endobronchial applications in the lung. The purpose of this work was to investigate the feasibility of CLA reconstruction when cardiac gating windows are imposed on acquired data.

Methods: 7 CLA sequences from a previous pig study (n=3) of endobronchial catheter navigation were analyzed using retrospectively-imposed cardiac gating windows. Each CLA sequence was reconstructed using a model-based device reconstruction approach, where each time point is reconstructed from a sliding window of projection images. The catheter model was represented by a cubic spline curve with 8 control points, which is optimized by minimizing a cost function representing the distance between segmented catheter centerlines in the 2D projection images and the forward projected digital model. Reconstructions were performed for three different gating intervals (30, 50 and 70% R-to-R) assuming heart rates of 60, 70, and 80 bpm and compared to a reference extracted from a conventional CBCT of a static device at the final device position.

Results: The mean and standard deviation of the root mean squared distance between the CLA reconstruction and the reference device position was 3.15±1.89 mm for a heart rate of 60 BPM and only 30% of projections in the gating window. The reference value was 2.78±1.71 mm for the reconstruction using 100% of projections. No significant differences (ANOVA, p > 0.99) were found between all combinations of gating interval and heart rates.

Conclusion: CLA reconstruction using gated projection data is feasible. These results inform future studies of intra-cardiac 3D device tracking such as during valvular, electrophysiology, and structural heart interventions.

Funding Support, Disclosures, and Conflict of Interest: Research was supported through a sponsored research agreement with Siemens Healthineers

Keywords

Gating, Reconstruction, Cone-beam CT

Taxonomy

IM- Cone Beam CT: Development (New Technology and Techniques)

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