Beyond the limits of space and time: Can 4D imaging enhance postmortem investigation?

Postmortem imaging has become an integral component of modern forensic pathology, with postmortem computed tomography (PMCT) and magnetic resonance (PMMR) imaging now routinely supplementing or, in selected cases, partially replacing conventional autopsy. Despite these advances, postmortem imaging remains predominantly static, capturing anatomy and injuries at a single point in time after death. In contrast, clinical radiology has increasingly embraced four-dimensional (4D) imaging approaches that incorporate time as a diagnostic dimension, enabling the assessment of motion, functional change, and dynamic processes. This narrative review with a conceptual perspective explores whether and how 4D concepts can be meaningfully translated into postmortem forensic imaging. By reviewing simulated motion models, multiphase PMCT angiography, ventilated PMCT, serial documentation of postmortem biological and physical processes, fracture mechanics research, and PMMR spectroscopy, it can be argued that time is already an implicit diagnostic dimension in forensic radiology. Although true real-time 4D imaging of the deceased remains technically limited, existing studies demonstrate that temporal reconstruction through controlled simulation and serial acquisition is feasible and forensically relevant. Embracing 4D thinking may allow postmortem imaging to evolve from static documentation toward a more process-oriented tool for reconstructing events and mechanisms leading to death. KEY POINTS: Question Can postmortem imaging provide time-related information that is already present after death? Findings 4D PMMCT and PMMR introduce time as an explicit element, allowing postmortem imaging to capture dynamic and evolving processes. Relevance statement This review highlights the emerging role of time-resolved ("4D") approaches in postmortem imaging, demonstrating how integrating temporal information can enhance reconstruction of injury mechanisms, postmortem processes, and medicolegal interpretation, thereby expanding forensic radiology beyond static documentation toward process-oriented forensic investigation.