Block-like and cast-like hyperdense areas in the right heart cavities on post-mortem CT strongly suggest the presence of intracardiac blood clots at autopsy

Objective: To classify the types of hyperdense areas in the heart cavities on post-mortem CT (PMCT) and compare them according to the presence of blood clots in the heart cavities at forensic autopsy. Methods: One hundred and twelve cases with CT images taken before forensic autopsy were evaluated. The presence and shape of hyperdense areas in the right or left heart cavities were retrospectively evaluated on PMCT images and were classified into four types (block-like, cast-like, fluid level-like, and unclear). The presence of blood clots was confirmed when there were clots in the heart cavities at forensic autopsy. Results: Of the 112 cases, 57 exhibited blood clots in the heart cavities at forensic autopsy. The hyperdense areas in the right heart cavities on PMCT in 57 cases exhibiting blood clots at forensic autopsy were classified as follows: block-like, 32; fluid level-like, 4; cast-like, 17; and unclear, 4. The sensitivity of block-like and cast-like hyperdense areas in the right heart cavities on PMCT for the presence of clots in the heart cavities at forensic autopsy was 86% (95% confidence interval [CI]: 74–94%); the corresponding specificity, PPV, and NPV were 95% (95% CI: 85–99%), 94% (95% CI: 84–99%), and 87% (95% CI: 75–94%), respectively. Conclusion: Block-like and cast-like hyperdense areas in the right heart cavities on PMCT predicted the presence of intracardiac blood clots at forensic autopsy. Key Points: • Clinical radiologists likely have no experience of interpreting findings of blood clots on post-mortem CT (PMCT). • The appearance of blood clots on PMCT provides important clues for diagnosing the cause and process of death. • The shapes of the hyperdense areas in the heart cavities were classified into four types, and two of these types could be used to predict the presence of blood clots in the heart cavities at forensic autopsy.