A Comparative Observational Study of Postmortem Computed Tomography and Traditional Forensic Autopsy Findings in Hanging Cases

Abstract

Background: The use of advanced radiological techniques is rising in the field of forensics to supplement and validate the evidence. Postmortem Computed Tomography (PMCT) is now used as a standard procedure in many institutions to augment traditional autopsy findings. The application of PMCT in hanging cases will greatly reduce the number of invasive traditional autopsies, as hanging is the most common method of suicide in Northern parts of India. Therefore this observational study was conducted to compare PMCT with traditional autopsy in fifty hanging cases. Result: Out of 50 cases, the age of the subjects ranged between 14 years and 70 years. PMCT with the help of 3D reconstruction was able to detect external ligature marks on the neck in 92% (N=46) of cases giving a sensitivity of 92% (CI = 80.77% to 97.78%). Skin and subcutaneous tissue desiccation were identifiable in 96% (N=48) by PMCT, giving a sensitivity of 96% (CI= 86.29% to 99.51%). The muscle hemorrhage was identified in 4% (N=2) of the cases in traditional autopsy while the authors found difficulty in interpreting the muscle hemorrhage in PMCT. In detecting thyroid cartilage fracture, the sensitivity of PMCT was found to be 100% (CI= 15.81% to 100.00%) and specificity of 100% (CI=92.60% to 100.00%). In detecting hyoid bone fracture, the sensitivity was 100% (CI= 2.50% to 100.00%), and specificity of 100% (CI=92.60% to 100.00%). In addition, there was a great degree of agreement between the two observers for these findings suggesting the reproducibility of the result. Conclusions: A consistency in findings of both the PMCT and traditional autopsy was found. However, CT was unable to detect muscle hemmorhages, compared to traditional autopsy. Authors suggest the use of CT angiography to overcome this shortcoming, till then CT can only augment invasive autopsy findings not replace it