High-resolution bone imaging and spectral soft-tissue contrast in post-mortem photon-counting CT

Photon-counting detector (PCD) computed tomography (CT) offers reduced image noise, high spatial resolution, and intrinsic spectral imaging capabilities, making it a promising technology for post-mortem CT. However, the relative contribution of PCD-CT to post-mortem imaging still needs to be characterized. This short communication provides a stepwise evaluation of key determinants of image quality in PMCT using a controlled post-mortem animal model. Whole-body CT was performed on a single post-mortem animal specimen using a PCD CT system and a conventional energy-integrating detector (EID) CT system under matched acquisition and reconstruction conditions. Image quality was evaluated sequentially by comparing background noise characteristics between detector types, assessing high-resolution photon-counting CT protocols for osseous structures, and analyzing soft-tissue image quality using SNR and CNR under both polychromatic and virtual mono-energetic reconstruction conditions. PCD CT demonstrated significantly lower background noise compared with EID CT ( p < 0.01). High-resolution PCD CT markedly improved visualization of fine osseous and pulmonary structures, while no consistent qualitative benefit for soft tissue was visually observed. Under matched polychromatic conditions, soft-tissue contrast improvements were modest and tissue-dependent. The most pronounced soft-tissue advantages were observed with spectral imaging, where virtual mono-energetic reconstructions showed a strong energy-dependent behavior. CNR improvements were organ-specific, with clear benefits for renal parenchyma but not for liver tissue. These findings indicate that the principal added value of PCD CT in post-mortem imaging is task-dependent. Detector-related noise reduction provides a robust baseline benefit, high-resolution imaging primarily enhances osseous assessment, and spectral reconstructions offer the greatest potential for soft-tissue optimization.