Assessing beam hardening artifacts in coronary stent imaging using different CT acquisition parameters on photon-counting detector computed tomography.

Purpose: To evaluate whether different scan protocols using a first-generation dual-source photon-counting CT (PCD-CT) can reduce coronary stent artifacts and improve image quality in patients with chronic coronary artery disease (CAD) and in-stent restenosis (ISR).

Materials and methods: Patients undergoing CCTA for suspected ISR or progression of CAD were consecutively enrolled between November 2021 and February 2023. Patients were scanned on a dual-source PCD-CT using standard acquisition mode with collimation of 144 × 0.4 mm or ultra-high-resolution (UHR) mode with collimation of 120 × 0.2 mm. Tube voltages were set at 120 or 140 kV. Scans were reconstructed using a standard kernel (Bv48), with UHR scans also reconstructed using a sharper kernel (Bv56).

Results: A total of 25 patients were included in the study, of whom 80% were male, with a mean age of 68 ± 8 years (IQR 64.8-75.3). UHR mode, particularly with Bv56 kernels, provided significantly thinner vessel walls and reduced beam hardening artifacts compared to standard mode and Bv48 kernel, especially at lower tube voltages. Noise levels varied, with generally lower noise in UHR scans.

Conclusion: UHR mode with Bv56 kernels improves artifact reduction and vessel visualization in coronary stents, offering advantages over standard CCTA protocols. These findings may enhance the clinical diagnosis of ISR, leading to better patient outcomes through improved treatment planning.