Relevant findings on postmortem CT and postmortem MRI in hanging, ligature strangulation and manual strangulation and their additional value compared to autopsy – a systematic review

Abstract

Several articles have described the use of postmortem computed tomography (CT) and postmortem magnetic resonance imaging (MRI) in forensic medicine. Although access to CT scanners and, particularly, access to MRI scanners, is still limited for several institutes, both modalities are being applied with increasing frequency in the forensic setting. Certainly, postmortem imaging can provide crucial information prior to autopsy, and this method has even been considered a replacement to autopsy in selected cases by some forensic institutes. However, the role of postmortem imaging has to be assessed individually according to various injury categories and causes of death. Therefore, this systematic review focuses on the role of postmortem CT and MRI in cases of hanging and ligature and manual strangulation. We assessed the most common and relevant findings on CT and MRI in cases of strangulation and compared the detectability of these findings among CT, MRI and autopsy. According to the available literature, mainly fractures of the hyoid bone or thyroid cartilage were investigated using postmortem CT. Compared to autopsy, CT demonstrated equivalent results concerning the detection of these fractures. A currently described "gas bubble sign" may even facilitate the detection of laryngeal fractures on CT. Regarding the detection of hemorrhages in the soft tissue of the neck, postmortem MRI is more suitable for the detection of this "vital sign" in strangulation. Compared to autopsy, postmortem MRI is almost equally accurate for the detection of hemorrhages in the neck. Another "vital sign", gas within the soft tissue in hanging, which is hardly detectable by conventional autopsy, can be clearly depicted by CT and MRI. The number of cases of manual and ligature strangulation that were investigated by means of postmortem CT and MRI is much smaller than the number of cases of hanging that were investigated by CT and MRI. Likewise, judicial hanging and the hangman's fracture on postmortem imaging were described in only a few cases. Based on the results of this systematic review, we discuss the additional value of CT and MRI in fatal strangulation compared to autopsy, and we reflect on where the literature is currently lacking.

Postmortem Computed Tomography and Magnetic Resonance Imaging of Gunshot Wounds to the Neck

“…In the present case, postmortem MRI was not only able to visualize the soft tissue injuries better than CT, as frequently mentioned in the literature , but also enabled the visualization of the wound channel without obfuscation by metal artifacts, as was the case on CT. A gunshot wound with a lodged bullet may reduce the diagnostic value of CT. The radiologic assessment of gunshot injuries can be severely impeded on CT due to metal artifacts caused by the lodged bullet; thus, an MRI examination may be of particular value for such nonperforating gunshot wounds.…”

Postmortem Magnetic Resonance Imaging and Postmortem Computed Tomography in Ligature and Manual Strangulation

“…Intramuscular hemorrhages are the most prominent collateral injury in cases of ligature and manual strangulation Most data about injuries in strangulation are obtained from hanging. [1][2][3] Certain characteristic traumatic injuries have been described throughout the years. Laryngeal fractures are a common injury in addition to soft tissue lesions, such as subcutaneous, intramuscular, and lymph node, and glandular hemorrhages and swellings.…”

“…1,13,14 During the process of strangulation, neck injuries occur frequently, which can be visualized by computed tomography (CT), magnetic resonance imaging (MRI), or autopsy. 3,[15][16][17][18][19] According to these studies, intramuscular hemorrhages and subcutaneous bleeding are considered important indicators of severity. In those studies, MRI showed a significant value in detecting these injuries.…”

“…No studies can be found in the literature regarding ligature strangulation on MRI. 3 In our study, we describe 6 individuals who died of ligature and manual strangulation who underwent a whole-body CT, neck and head MRI, and an autopsy. In addition to CT, we analyzed all MRI examinations focusing on hemorrhages.…”

Conventional X-ray as an additional tool in the analysis of fatal neck trauma

“…We read with great interest the review article by Dominic Gascho et al [1] about relevant findings on post-mortem total body CT (TBCT)/MRI in cases of strangulation. The authors describe fracture patterns and hemorrhages in strangulation cases, but they admit that large-scale studies for relevant findings on CT and MRI related to strangulation are lacking.…”