Diagnostic tips for multi-phase post-mortem computed tomography angiography interpretation in upper gastro-intestinal bleeding.

In the past 10 years, the Multi-phase Post-mortem Computed Tomography Angiography (MPMCTA) has considerably improved the quality and precision of postmortem diagnoses, particularly in cases with vascular implication. MPMCTA is known to have higher sensitivity for detecting the source of a hemorrhage than autopsy. Death by upper gastro-intestinal (GI) bleeding is not so uncommon in forensic practice. MPMCTA, like any other diagnostic test, can produce artifacts that must be recognized. Radiologists at our center have previously encountered images suggestive of upper GI bleeding that were ultimately identified as artifacts during autopsy. This is why we believe it is essential to establish criteria to differentiate true bleeding from artifacts. The aim of our study was to compare the diagnostic value of MPMCTA and autopsy in detecting and localizing sources of upper GI bleeding, and to establish diagnostic criteria to aid in the interpretation of upper GI contrast extravasation on angiography. We conducted a retrospective cross-sectional study, analyzing MPMCTA and autopsy data from 326 human bodies. In the GI tract, contrast extravasation should not be immediately interpreted as a sign of active bleeding. In cases of true GI hemorrhage, MPMCTA reveals specific features suggestive of bleeding, such as hyperdense material within the GI tract on native CT, and a focal contrast leakage during the arterial or venous phase. This article offers tips that may help radiologists and forensic pathologists distinguish true bleeding from artifacts when interpreting MPMCTA findings in the upper GI tract.