Assessment of interstitial lung disease in a systemic sclerosis patient cohort using photon-counting detector CT with ultra-high resolution and a 1024-pixel image matrix

This study assessed the potential of ultra-high resolution (UHR) and a 1024-matrix in photon-counting-detector CT (PCD-CT) for evaluating interstitial lung disease (ILD) in systemic sclerosis (SSc) patients. Sixty-six SSc patients who underwent ILD-CT screening on a first-generation PCD-CT were retrospectively included. Scans were performed in UHR mode at 100 kVp with two different matrix sizes (512×512 and 1024x1024) and reconstructed at slice thicknesses of 1.5 and 0.2 mm. Image noise, subjective image quality, and ILD changes (ground glass opacities and reticulations) were evaluated on a 5-point Likert-scale by two independent readers. Interreader agreement for subjective image quality ranged from fair to almost perfect (Krippendorff-Alpha: 0.258-0.862). Overall image quality was highest for 1.5 mm/1024 matrix images [(reader 1: 4(4.4), reader 2: 5(4.5)]. Image sharpness was rated significantly better in 0.2 mm images (P