Room: Track 1
Purpose: development of smarter and safer 3D cardiac imaging via (Adaptive CaRdiac cOne BEAm computed Tomography (ACROBEAT). ACROBEAT uses real-time adaption of the gantry velocity and projection rate of an imaging system in response to a patient’s electrocardiogram (ECG) to maintain or improve image quality while significantly reducing imaging dose. Here, we report on the first experimental implementation of ACROBEAT.
Methods: Siemens ARTIS pheno robotic angiography system in conjunction with a Siemens Test Automation Control System (TACS) was used to implement both ACROBEAT and a retrospective ECG-gated multisweep protocol. To simulate patient motion, the CIRS Dynamic Cardiac Phantom containing calcification and iodine contrast targets was programmed with a patient-measured ECG trace with an average heart rate of 86 bpm. Image quality metrics of structural similarity index (SSI) and contrast-to-noise-ratio (CNR) and were used to compare and characterise the reconstructed images from the ACROBEAT and retrospective ECG-gated multisweep protocols.
Results: successfully modulated the gantry velocity and projection rate of the imaging system with respect to a patient’s ECG signal in real-time. The ACROBEAT reconstructed images matched the image quality of the retrospective ECG-gated multisweep reconstructed images. Specifically, they had a SSI of 98%. Additionally around the contrast targets, ACROBEAT enabled a CNR of 1.82 compared to 1.42 for the retrospective ECG-gated multisweep protocol. ACROBEAT also provides an unprecedented 85% reduction in overall imaging dose compared with a retrospective ECG-gated multi-sweep acquisition. However, total scan time for the ACROBEAT protocol increased x3 compared to the retrospective ECG-gated protocol due to a limit on the maximum gantry velocity under control of the Siemens TACS.
Conclusion: a world-first, we have implemented our real-time adaptive cardiac protocol, ACROBEAT, on a commercial imaging system. Phantom experiments demonstrate that ACROBEAT substantially reduces dose while maintaining image quality.
Funding Support, Disclosures, and Conflict of Interest: This research was supported by a Siemens grant. The concept and information presented in this paper are based on research and is not commercially available. Due to regulatory reasons its future availability cannot be guaranteed. Also supported by grant #1123068 through the Priority-driven Collaborative Cancer Research Scheme by Cancer Australia.