Photon-counting CT-angiography in comparison to digital subtraction angiography and MR-angiography for assessing intra-aneurysmal flow disrupting devices

PURPOSE: This study aimed to evaluate the potential of Photon-Counting Detector CT Angiography (PCD-CTA) for the post-interventional assessment of intraaneurysmal flow disrupting devices (IAFD). METHODS: This retrospective analysis evaluates consecutive patients with intracranial aneurysms treated with IAFD between April 2023 and April 2025, who underwent PCD-CTA, MR angiography and DSA as part of their clinical diagnostic work-up routine. Polyenergetic images, iodine and virtual monoenergetic imaging reconstructions with different keV levels (40 and 80) and with different Head vessel kernels (Hv56 and Hv72) were acquired with and without iterative metal artifact reduction. Three independent readers assessed image quality using a 5-point Likert scale and region of interest analysis. The different kernels, keV and the optimized spectral reconstructions were compared in descriptive analysis. RESULTS: A total of 10 patients (mean age 60.41 ± 11.43 (43-74) years; 6 women) with intracranial aneurysms treated with either Contour device (n = 6) or WEB device (n = 4) were included. Reconstructions using Hv56 and a 40 keV yielded increased signal and contrast to noise ratios and were preferred for visualizing the parent vessel lumen compared to Hv72 and higher keV levels (p < 0.001). Assessing the different spectral reconstructions virtual monoenergetic reconstructions proved to be best to evaluate the parent vessel lumen (p = 0.040). CONCLUSION: Spectral reconstructions of PCD-CTA with a smoother reconstruction kernel and a low keV level seem to be beneficial to achieve optimal image quality for the diagnostic evaluation of patients with intracranial IAFD.