Hypostasis (also called livor mortis) refers to the purplish discolouration of the superficial layers of dependent areas of the skin occurring soon after death. In reality the mechanisms causing hypostasis cause changes in every organ in the body.
In one study imaging evidence of hypostasis was seen in 52% of post-mortem CT scans 3.
Due to the stasis of blood occurring after death, blood separates into serum and erythrocytes 1. Erythrocytes being heavier undergo sedimentation and form a dependent layer (or haematocrit level) in the superficial tissues, internal organs and large blood vessels. Sedimentation occurs within 2 hours post mortem 2,3.
Hypostasis appears as a gradient of increasing hyperdensity when moving from non-dependent to dependent regions of organs, tissues or the great vessels. Subtle dermal thickening may also be present in dependent areas 1.
- T1: a gradient of increasing hyperintensity in dependent regions of the organ 1.
On CT imaging consider
- 1. Offiah CE, Dean J. Post-mortem CT and MRI: appropriate post-mortem imaging appearances and changes related to cardiopulmonary resuscitation. (2016) The British journal of radiology. 89 (1058): 20150851. doi:10.1259/bjr.20150851 - Pubmed
- 2. Shiotani S, Kohno M, Ohashi N, Yamazaki K, Itai Y. Postmortem intravascular high-density fluid level (hypostasis): CT findings. (2002) Journal of computer assisted tomography. 26 (6): 892-3. Pubmed
- 3. Levy AD, Harcke HT, Mallak CT. Postmortem imaging: MDCT features of postmortem change and decomposition. (2010) The American journal of forensic medicine and pathology. 31 (1): 12-7. doi:10.1097/PAF.0b013e3181c65e1a - Pubmed