Evaluation on the Feasibility of the Pulse Oximetry–triggered Coronary CT Angiography

Purpose To evaluate the feasibility of performing pulse oximetry-triggered coronary CT angiography (CCTA) for diagnostic imaging in cardiac participants who cannot or have difficulty being connected to electrocardiographic (ECG) devices. Materials and Methods This prospective study enrolled consecutive participants scheduled for CCTA on a 16-cm z-axis coverage CT from June to July 2023. Half of the study participants underwent CCTA triggered by a simulated virtual ECG signal based on heart rate monitoring via pulse oximetry (pulse oximetry-triggered group), and the other half underwent traditional ECG-triggered CCTA (ECG group). All images were reconstructed using motion correction and deep learning image reconstruction algorithms. Comparisons were made regarding radiation dose, contrast agent dose, examination time, and subjective and objective image quality assessments between the two groups. Results Three hundred participants (mean age ± SD, 57 years ± 12; 161 male) were included. The total examination time of the pulse oximetry-triggered group (<i>n</i> = 150) was significantly lower than that of the ECG group (<i>n</i> = 150) (313.23 seconds ± 59.59 s vs 743.25 seconds ± 75.35; <i>P</i> < .001). There was no evidence of a difference between the pulse oximetry-triggered and ECG groups in terms of radiation and contrast media dose (all <i>P</i> > .05). The pulse oximetry-triggered and ECG groups had comparable values for CT attenuation, image noise, signal-to-noise ratio, and contrast-to-noise ratio of the main coronary vessels, as well as overall image quality (all <i>P</i> > .05). Conclusion The study demonstrated that CCTA with the pulse oximetry-triggered protocol on a 16-cm z-axis coverage CT with cardiac motion correction algorithm and deep learning image reconstruction algorithms provide comparable image quality to traditional ECG-triggered CCTA at similar radiation and contrast doses while significantly reducing examination time. <b>Keywords:</b> Applications-CT, CT-Angiography, CT-Coronary Angiography <i>Supplemental material is available for this article.</i> © RSNA, 2025.