The radiodensity of cerebrospinal fluid and vitreous humor as indicator of the time since death.
OBJECTIVE
After death, a series of changes occur naturally in the human body in a fairly regular pattern. These postmortem changes are detectable on postmortem CT scans (PMCT) and may be useful in estimating the postmortem interval (PMI). The purpose of our study is to correlate the PMCT radiodensities of the cerebrospinal fluid (CSF) and vitreous humor (VH) to the PMI.


METHODS
Three patient groups were included: group A consisted of 5 donated cadavers, group B, 100 in-hospital deceased patients, and group C, 12 out-of-hospital forensic cadavers. Group A were scanned every hour for a maximum of 36 h postmortem, and the tympanic temperature was measured prior to each scan. Groups B and C were scanned once after death (PMI range 0.2-63.8 h). Radiodensities of the VH and CSF were measured in Hounsfield units. Correlation between density and PMI was determined using linear regression and the influence of temperature was assessed by a multivariate regression model. Results from group A were validated in groups B and C.


RESULTS
Group A showed increasing radiodensity of the CSF and VH over time (r (2) CSF, 0.65). PMI overruled the influence of temperature (r = 0.99 and p = 0.000). Groups B and C showed more diversity, with CSF and VH radiodensities below the mean regression line of Group A. The formula of this upper limit indicated the maximum PMI and was correct for >95 % of the cadavers.


CONCLUSIONS
The results of group A showed a significant correlation between CSF radiodensity and PMI. The radiodensities in groups B and C were higher than in group A, therefore the maximum PMI can be estimated with the upper 95 % confidence interval of the correlation line of group A.
Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 25, 6525 GA, Nijmegen, The Netherlands.
Desirée H J L M
DH
Koopmanschap
Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 25, 6525 GA, Nijmegen, The Netherlands.
Alireza R
AR
Bayat
Department of Pathology, Netherlands Forensic Institute, Laan van Ypenburg 6, 2497 GB, Den Haag, The Netherlands.|Department of Pathology, Maastricht University Medical Center, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.
Bela
B
Kubat
Department of Radiology, Groene Hart Ziekenhuis, Bleulandweg 10, 2803 HH, Gouda, The Netherlands.
Henri M
HM
de Bakker
Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 25, 6525 GA, Nijmegen, The Netherlands.
Mathias W M
MW
Prokop
Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 25, 6525 GA, Nijmegen, The Netherlands. willemijn.klein@radboudumc.nl.
Willemijn M
WM
Klein
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001831:Body Temperature; D002555:Cerebrospinal Fluid / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011180:Postmortem Changes; D014057:Tomography, X-Ray Computed; D014822:Vitreous Body / Q000000981:diagnostic imaging*; D055815:Young Adult
Cerebrospinal fluid; Postmortem computed tomography; Postmortem interval; Radiodensity; Vitreous humor