Scientific article
Open access

Development and validation of a postmortem radiological alteration index: the RA-Index

Published inInternational journal of legal medicine, vol. 126, no. 4, p. 559-566
Publication date2012

This study aimed to derive an index quantifying the state of alteration of cadavers by quantifying the presence of gas in the body using postmortem multidetector computed tomography (MDCT) imaging, and to validate the index by defining its sensitivity and specificity. The RA (radiological alteration)-index was derived from postmortem MDCT data from 118 nontraumatically deceased people. To validate the index, 100 additional scanned bodies (50 % traumatically deceased) were retrospectively examined by two independent observers. Presence of gas at 82 sites was assessed by a radiologist, whereas a forensic pathologist only investigated the seven sites used for the RA-index. The RA-index was highly correlated to the overall presence of gas in all 82 sites (R(2) = 0.98 in the derivation set and 0.85 in the validation set). Semiquantitative evaluation of gas presence in each site showed moderate reliability (Cohen's kappa range, 0.41-0.78); nevertheless, the overall RA-index was very reliable (ICC(2,1) = 0.95; 95 % CI 0.92-0.96). Examiner using the RA-index detected heart cavities full of gas with a sensitivity of 100 % (95 % CI 51.7-100) and a specificity of 98.8 % (92.6-99.9). We conclude that determining the presence of gas at seven sites is a valid means to measure the distribution of gas due to cadaveric alteration in the entire body. The RA-index is rapid, easy-to-use, and reliable for nonexperienced users, and it is a valid method to suspect the normal presence of gas from cadaveric alteration. MDCT can be used to screen for gas embolism and to give indications for gas composition analysis (gas chromatography).

Citation (ISO format)
EGGER, Coraline et al. Development and validation of a postmortem radiological alteration index: the RA-Index. In: International journal of legal medicine, 2012, vol. 126, n° 4, p. 559–566. doi: 10.1007/s00414-012-0686-6
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Article (Published version)
ISSN of the journal0937-9827

Technical informations

Creation11/07/2012 12:03:00 AM
First validation11/07/2012 12:03:00 AM
Update time03/14/2023 7:54:40 PM
Status update03/14/2023 7:54:40 PM
Last indexation01/16/2024 12:49:21 AM
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