Assessing perceived image quality in grating interferometry breast CT: a blinded reader study with scans of fresh tumourectomies

Abstract Objectives Grating-interferometry breast CT (GI-BCT) is an experimental imaging technique that has been shown to outperform state-of-the-art imaging techniques in terms of contrast-to-noise ratio by providing additional phase-contrast information (fused images) alongside conventional attenuation-only images. We aimed to provide insight into the qualitative advantage of GI-BCT using an experimental imaging setup and ex vivo samples. Materials and methods In this ethics-approved study (EKNZ 2015-132), we employed our laboratory-based GI-BCT system to capture attenuation-only and fused images of five fresh tumourectomy samples. A dose range of 22–176 mGy mean absorbed breast dose was selected based on a previous study with the system to investigate dose-dependent image quality. Images were rated on a 5-point Likert scale in multiple categories by five experienced breast radiologists in a blinded reader study based on perceived quality. Ratings were analysed with the two-tailed Wilcoxon signed-rank test. Inter-reader agreement was assessed using Krippendorff’s alpha and Kendall’s W. Dose dependence was analysed using ordinal regression. Results Analysis of the qualitative reading results showed a significant preference for fused GI-BCT images over attenuation-only images when using the same photon statistics (dose at the detector). For the same mean absorbed breast dose, only half of the measurements could be used for analysis (accounting for the influence of the gratings), and no significant preference could be reported. Conclusion Our findings highlight the promising potential of GI-BCT. With continued advancements aimed at reducing the absorbed dose to the breast, this technology is well-positioned to play a significant role in future in vivo diagnostic practices. Key Points Question Can grating-interferometry-based breast computed tomography improve image quality perceived by medical doctors compared to conventional breast imaging techniques relying solely on attenuation information? Findings In a blinded reader study, grating-interferometry-based images including phase information were consistently rated higher in quality than conventional attenuation-based breast images. Relevance statement These results provide the first clinical reader-based evidence supporting grating-interferometry computed tomography, suggesting potential to enhance diagnostic confidence and image interpretation quality, and highlighting its promise as an advanced tool for future breast imaging applications.