Re-defining Organ Weights in the Era of Virtopsy: Systematic Review of Postmortem Computed Tomography Volumetry versus Autopsy

Abstract Postmortem computed tomography (PMCT) has emerged as an important adjunct or alternative to conventional autopsy in forensic pathology, offering noninvasive visualization and quantitative assessment of internal organs. Accurate organ weight determination remains fundamental for diagnosing pathological conditions such as hypertrophy, edema, or atrophy; however, traditional autopsy weighing is invasive and resource intensive. This systematic review synthesized primary studies comparing PMCT-derived organ volumes with corresponding autopsy organ weights in adult decedents to evaluate correlation strength, agreement metrics, and pragmatic conversion factors. Following PRISMA 2020 and COSMIN guidance, eleven eligible studies published between 2014 and 2022 were included, encompassing liver, heart, lungs, and spleen volumetry. Across studies, liver and ex vivo heart measurements demonstrated strong correlations with autopsy weights ( r 0.90–0.95 and R 2 0.74–0.93) and near-unity density conversion factors around 1.0 g/mL with minimal systematic bias. In situ whole-heart models required lower calibration factors (approximately 0.45–0.50 g/mL) due to chamber air and intravascular blood. Lung volumetry showed substantial predictive performance ( R 2 0.84–0.91) when attenuation-stratified models were applied, though variability increased in cases of edema, congestion, or prolonged postmortem interval. Splenic volumetry demonstrated moderate correlation, with conversion factors around 1.05 g/mL but notable sensitivity to postmortem shrinkage and density changes. Overall, PMCT volumetry provides a reproducible and scientifically supported surrogate for autopsy organ weights, particularly for the liver and heart when imaging and segmentation protocols are standardized. While variability remains for lungs and spleen due to postmortem physiological changes, incorporation of calibrated PMCT-based mass estimation into virtopsy workflows represents a practical and minimally invasive advancement in contemporary forensic practice.