Synchrotron phase-contrast CT of a human lung from forensic autopsy: a single-case technical feasibility study

Background Postmortem CT is the principal cross-sectional imaging modality in forensic practice; however, postmortem CT-based pulmonary assessment is challenged by insufficient spatial resolution and density artifacts from postmortem lung collapse, atelectasis, and gravitational fluid redistribution, often preventing reliable distinction between true pathology and postmortem changes. Propagation-based synchrotron phase-contrast CT (PBI-CT) offers enhanced soft-tissue contrast and sub-0·1 mm spatial resolution, potentially overcoming these constraints. We aimed to investigate the feasibility of whole-organ PBI-CT of a human lung freshly obtained at forensic autopsy. Methods This single-case, technical feasibility study was conducted on a whole, unfixed lung from a male decedent (born in 1963) with fatal citalopram intoxication and no external trauma. Postmortem CT was conducted at Cattinara University Hospital, Trieste, Italy, on the intact cadaver 5 days postmortem to examine the lung before explantation. Forensic autopsy was conducted 9 days postmortem at the Department of Forensic Medicine, University of Trieste, Trieste, Italy. PBI-CT was subsequently conducted on the explanted lung within an anthropomorphic chest phantom under passive inflation at the Synchrotron Radiation for Medical Physics beamline of the Elettra synchrotron source, Trieste, Italy, using a photon-counting detector (100 μm nominal pixel size; 10·70 m sample-to-detector distance; and 67 μm effective isotropic voxel size). Findings PBI-CT preserved near-physiological lung geometry and lung aeration and showed less extensive high-density regions than postmortem CT. The dataset revealed sharply delineated bronchial trees, secondary pulmonary lobules, interlobular septa, peripheral bronchiolar walls, and small arterioles at submillimetre scale and enabled three-dimensional assessment of heterogeneous parenchymal alterations, including regions consistent with intra-alveolar oedema, vascular congestion, or microhaemorrhage in the PBI-CT image. Interpretation Whole-organ PBI-CT of an unfixed human lung from forensic autopsy, imaged within an anthropomorphic chest phantom, is technically feasible and showed less extensive postmortem density artifacts, greater soft-tissue contrast, and higher spatial resolution than postmortem CT. PBI-CT might serve as a non-destructive volumetric adjunct for forensic pulmonary imaging, particularly in contested cases with heterogeneous parenchymal pathology, such as drug-related pulmonary injury.