In this series of sudden natural deaths, MPMCTA showed a high degree of concordance with autopsy for major vascular lesions, particularly aortic rupture/dissection, coronary thrombosis, neoplastic vascular involvement, and pulmonary arterial filling defect consistent with pulmonary thromboembolism. Our findings are consistent with a broad and heterogeneous body of international literature indicating that post-mortem CT angiography (PMCTA) provides a substantial diagnostic advantage over non-contrast PMCT alone in the assessment of the vascular system. Studies conducted in different forensic contexts have consistently demonstrated that PMCTA improves visualization of the arterial tree, allowing identification and localization of vascular ruptures, occlusions, and hemorrhagic sources that may be difficult to recognize at conventional autopsy or on unenhanced PMCT alone [10,11,12,13].

In agreement with previous reports, non-contrast PMCT in our series proved to be an effective screening tool, particularly for the evaluation of cardiac size, gross cardiac morphology, and the presence of coronary artery calcifications. The ability of PMCT to document coronary and vascular calcifications has been widely described and confirms its value in identifying chronic atherosclerotic disease and vascular calcifications in post-mortem investigations [13,14,15]. Nevertheless, unenhanced PMCT remains intrinsically limited in the evaluation of non-calcified plaques, luminal narrowing, and intravascular thrombosis.

By contrast, MPMCTA enables direct visualization of the coronary lumen and vessel wall, improving the detection and localization of both calcified and non-calcified atherosclerotic lesions, luminal stenosis, and coronary thrombosis. Previous studies have shown that MPMCTA can accurately identify coronary filling defects, occlusions, and plaque-related luminal abnormalities, with good correlation with autopsy and histological findings, both in whole-body examinations and in targeted or isolated-organ approaches [4, 15,16,17,18,19,20]. In our series, these advantages were reflected by the high concordance observed for major vascular lesions. Nevertheless, our findings also highlight the limitations of the technique, as one coronary artery dissection causing acute myocardial infarction was not identified by MPMCTA and was detected only at autopsy and histological examination.

Histological examination therefore remained essential for definitive cause-of-death determination in cases of acute myocardial infarction in the present series. Although infarct-related coronary thrombosis was identified by MPMCTA in 2 of the 5 cases, the diagnosis of acute myocardial infarction ultimately relied on histological examination. Histology was also required for the diagnosis of previous myocardial infarction, myocardiosclerosis, and lymphocytic myocarditis.

Several authors have emphasized that, despite the ability of PMCTA to identify coronary stenosis and thrombosis, histological examination remains indispensable for confirming acute myocardial injury and timing of ischemic events [4]. These limitations have prompted interest in post-mortem magnetic resonance imaging as a complementary technique for myocardial tissue characterization in selected cases [19].

A relevant contribution of MPMCTA emerged in cases of cardiac tamponade due to hemopericardium. In all such cases, angiographic imaging allowed precise identification of the vascular source of bleeding and accurate delineation of aortic rupture or dissection prior to autopsy. This finding is consistent with previous reports demonstrating the superiority of PMCTA in localizing vascular ruptures and hemorrhagic sources that may be difficult to identify through conventional autopsy alone [10, 12]. Similar advantages have been described in venous and arterial ruptures, as well as in rare but fatal conditions such as bronchovascular fistulas, where PMCTA enables clear visualization of abnormal vascular communications before anatomical disruption [21, 22].

Pulmonary findings further confirmed the complementary roles of post-mortem imaging and histological examination. In the present series, one case of pneumonia could only be diagnosed microscopically, highlighting the role of histological analysis for the characterization of non-vascular pulmonary pathology. While non-contrast PMCT reliably demonstrated findings consistent with pulmonary edema and interstitial changes, MPMCTA proved useful in documenting the extent and precise localization of pulmonary arterial filling defects in one case subsequently diagnosed as pulmonary thromboembolism.

Previous studies have shown that PMCTA may provide useful clues for the identification of pulmonary thromboembolism, including the demonstration of intraluminal filling defects and their anatomical distribution within the pulmonary arterial tree [23, 24]. However, the distinction between antemortem pulmonary thromboembolism and postmortem clot formation remains challenging. Tian et al. reported that pulmonary PMCTA may demonstrate filling defects in both pulmonary thromboembolism and postmortem clotting, highlighting the limited specificity of imaging findings alone [23]. Similarly, recent reviews have emphasized that no universally accepted criteria currently exist for reliably differentiating antemortem thrombi, agonal thrombi, and postmortem clots on imaging [25]. Therefore, although MPMCTA may significantly improve visualization and localization of pulmonary arterial filling defects, definitive diagnosis still requires correlation with autopsy and histological findings.

In cases of neoplastic disease, PMCT accurately depicted the site and extent of solid organ lesions, whereas MPMCTA provided additional information regarding vascular involvement, including venous infiltration and abnormal vascular communications. These findings are consistent with previous reports in which PMCTA proved particularly valuable in complex oncological deaths characterized by hemorrhagic mechanisms or vascular erosion [12, 22].

Concerns have been raised regarding the potential impact of contrast agents used in PMCTA on histological interpretation. Recent studies have demonstrated that PMCTA does not significantly alter immunohistochemical biomarkers associated with coronary artery disease, supporting the safety of this technique from a histopathological perspective [26]. Furthermore, systematic analyses of histological artifacts induced by oily contrast agents have shown that such changes are recognizable and should be taken into account during microscopic evaluation, without compromising diagnostic accuracy [27, 28].

The practical value of MPMCTA in the present series extended beyond diagnostic correlation. In cases of aortic rupture/dissection, coronary thrombosis, and neoplastic vascular involvement, MPMCTA enables accurate pre-autopsy localization of major vascular lesions, including coronary thrombosis, aortic tears, and abnormal vascular communications. This information facilitated a more targeted autopsy approach, allowing focused examination of the affected vascular structures and more directed tissue sampling for histological confirmation.

Moreover, PMCTA offers the advantage of documenting vascular abnormalities before tissue manipulation. This aspect has also been emphasized in other forensic applications, where angiographic imaging enabled identification of vascular lesions that could be difficult to recognize or potentially altered during subsequent autopsy procedures [29].

From a practical perspective, the added value of MPMCTA should be balanced against the additional resources required for the examination. Our findings suggest that the technique is particularly valuable when a vascular mechanism of death is suspected, as MPMCTA provides detailed pre-autopsy anatomical information in these cases. Conversely, its contribution is more limited in pathological conditions whose diagnosis primarily relies on histological examination.

This interpretation is consistent with recent clinical experience showing that PMCTA may provide substantial additional diagnostic information in selected cases, while remaining most effective when integrated into a multidisciplinary post-mortem investigation rather than used as a standalone diagnostic tool [13].

Several limitations of the present study should be acknowledged. First, this was a monocentric study with a relatively small sample size, reflecting the limited number of cases meeting the inclusion criteria during the study period. Second, the study was primarily descriptive and was not designed to calculate diagnostic performance metrics such as sensitivity, specificity, or predictive values. Third, although coronary artery calcifications were assessed qualitatively, quantitative cardiovascular imaging parameters such as coronary artery calcium scoring (CACS) and epicardial fat volume (EFV) were not systematically evaluated. These parameters were intentionally excluded because they had already been investigated in dedicated analyses on subsets of the same forensic population [30, 31]. Finally, all cases originated from a single institutional and legal setting, which may limit the generalizability of the findings to other forensic systems and workflows.