AUTHOR=Wu Wenjie , Zhan Hefeng , Wang Yiran , Ma Xueyan , Hou Jiameng , Ren Lichen , Liu Jie , Wang Luotong , Zhang Yonggao 

TITLE=Improving image quality and in-stent restenosis diagnosis with high-resolution “double-low” coronary CT angiography in patients after percutaneous coronary intervention

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 11 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2024.1330824

DOI=10.3389/fcvm.2024.1330824

ISSN=2297-055X

ABSTRACT=Objective: To investigate the image quality of a high-resolution, low-dose coronary CT angiography (CCTA) with deep learning image reconstruction (DLIR) and second-generation motion-correction algorithms, SnapShot Freeze 2(SSF2) algorithm and its diagnostic accuracy for in-stent restenosis (ISR) in patients after percutaneous coronary intervention (PCI), in comparison with standard-dose CCTA with high-definition mode reconstructed by adaptive statistical iterative reconstruction Veo algorithm (ASIR-V) and the first-generation motion-correction algorithm, SnapShot Freeze 1(SSF1).  
Methods: Patients after PCI and suspected of having ISR scheduled for high-resolution CCTA (randomly for 100kVp low-dose CCTA or 120kVp standard-dose) and invasive coronary angiography (ICA) were prospectively enrolled in this study. After the basic information pairing, total 105 patients were divided into the LD group (60 patients underwent 100kVp low-dose CCTA reconstructed with DLIR and SSF2) and the SD group (45 patients underwent 120kVp standard-dose CCTA reconstructed with ASIR-V and SSF1). Radiation and contrast medium doses, objective image quality including CT value, image noise (standard deviation), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) for Aorta, left main artery (LM), left ascending artery (LAD), left circumflex artery (LCX), right coronary artery (RCA) of the two groups were compared. A 5-point scoring system was used for the overall image quality and stent appearance evaluation. Binary ISR was defined as an in-stent neointimal proliferation with diameter stenosis ≥ 50% to assess the diagnostic performance between the LD group and SD group with ICA as the standard reference.
Results: The LD group achieved better objective and subjective image quality than the SD group even with 39.1% radiation dose reduction and 28.0% contrast media reduction. The LD group improved the diagnostic accuracy for coronary ISR to 94.2% from the 83.8% of the SD group on the stent-level and decreased the ratio of false positive cases by 19.2%.
Conclusion: Compared with standard-dose CCTA with ASIR-V and SSF1, the high-resolution, low-dose CCTA with DLIR and SSF2 reconstruction algorithms further improves the image quality and diagnostic performance for coronary ISR at 39.1% radiation dose reduction and 28.0% contrast dose reduction.