Persistent or recurrent symptoms after percutaneous coronary intervention (PCI) often indicate complications such as in-stent restenosis (ISR), highlighting the need for reliable non-invasive assessments [1–3]. Coronary CT angiography (CCTA) using energy-integrating detector (EID) technology is increasingly used to assess ISR, but remains limited by suboptimal spatial resolution and metal artifacts. These limitations have historically impaired lumen assessment, particularly in small stents (<…