Improvement of the Visualization of the Adamkiewicz Artery Using a Virtual Non-Electrocardiogram-Gated Reconstruction in Electrocardiogram-Gated Computed Tomography Angiography for Aortic Diseases.

OBJECTIVE: Retrospective electrocardiogram (ECG)-gated CT angiography of the whole aorta is one of the most reasonable acquisition methods for simultaneously evaluating the aorta, coronary arteries, and the Adamkiewicz artery in the preoperative evaluation of aortic diseases. However, in retrospective ECG-gated reconstruction (ECG recon) of the Adamkiewicz artery, only a portion of the acquired data per heartbeat is used for image reconstruction. Therefore, we propose a virtual non-ECG-gated reconstruction (VNECG recon) for the Adamkiewicz artery by editing the ECG, which utilizes all acquired data. The purpose of this study is to evaluate the visualization of the Adamkiewicz artery using the VNECG recon.

METHODS: Fifty-three cases were analyzed using retrospective ECG-gated CT of the whole aorta from April 2023 to April 2024. We measured the signal-to-noise ratio (SNR) of the aorta and the contrast-to-noise ratio (CNR) of the anterior spinal artery relative to the spinal cord for both ECG recon and VNECG recon. The visualization scores of the Adamkiewicz artery were evaluated by 2 radiologists on a 4-point scale.

RESULTS: The SNR and CNR were improved with VNECG recon compared with those of ECG recon (P<0.001). The visualization scores of both observers were higher with VNECG recon than those with ECG recon (observer 1, 3.2±1.0 vs. 2.8±1.1, mean difference 0.4, 95% CI: 0.3-0.6, P<0.001; observer 2, 3.2±1.0 vs. 3.0±1.1, mean difference 0.2, 95% CI: 0.0-0.3, P=0.010, respectively).

CONCLUSIONS: The visualization of the Adamkiewicz artery was improved by using a VNECG recon method, which avoided discarding any acquired data during the retrospective ECG-gated CT acquisition.