Diffusion-weighted perinatal postmortem magnetic resonance imaging as a marker of postmortem interval

Abstract

ObjectiveTo evaluate perinatal body organ apparent diffusion coefficient (ADC) values at postmortem magnetic resonance imaging (PMMR) in order to evaluate postmortem changes.MethodsPostmortem diffusion-weighted imaging (DWI) of the thorax and abdomen were performed with diffusion gradient values b = 0, 500, and 1000 s/mm2 on 15 foetal and childhood cases (mean 33.3 ± 7.8 weeks gestation) compared to 44 live infants (mean age 75.5 ± 53.4 days). Mean ADC values were calculated from regions of interest (ROIs) for the lungs, liver, spleen and renal cortex, compared to normative live infantile body ADC values of similar gestational age.ResultsMean ADC values were significantly lower in postmortem cases than in normal controls for liver (0.88 10-3 mm2/s ± SD 0.39 vs. 1.13 ± 0.13; p < 0.05) and renal cortex (0.85 ± 0.26 vs. 1.19 ± 0.13; p < 0.05) but not spleen or muscle. Mean lung ADC values were significantly higher than normal controls (1.06 ± 0.18 vs. 0 ± 0; p < 0.001), and there was a significant correlation between postmortem interval and lung ADC (R2 = 0.55).ConclusionLung PMMR ADC values are related to postmortem interval, making them a potential marker of time since death. Further research is needed to understand the organ-specific changes which occur in the postmortem period.Key Points• Liver and spleen PM ADC values were lower than controls.• Lung ADC changes correlate with PM interval.• These findings may be useful in medicolegal cases.

High resolution isotropic diffusion imaging in post-mortem neonates: a feasibility study

“…T-test results are shown in Figure 2.Average MD values were obtained from all organs in all cases and shown inFigures 3 respectively. Brain and solid organ MD values are comparable to those obtained in previous studies(6,7). Myocardium and psoas muscle were found to have the highest MD values(Figure 3).…”

“…We have demonstrated feasibility of using a multiband diffusion imaging sequence in the perinatal post mortem setting. This sequence allowed the acquisition of higher (isotropic) with gradient values of 0, 500, 1000 s/mm 3 (6,7,20). We also note that other published work often quotes ADC values, although it is frequently unclear whether a single direction or the average of three directions was measured.…”

“…Diffusion MRI is a non-invasive method that is exquisitely sensitive to water diffusion. Advanced diffusion image acquisition and processing aims to probe the cellular diffusion environment and may throw light on different processes occurring within the tissue (3)(4)(5), which in turn has the potential to be predictive of clinical factors relating to time from and cause of death (6)(7)(8).…”

The radiodensity of cerebrospinal fluid and vitreous humor as indicator of the time since death

“…Other radiological methods for the PMI estimation have been investigated, such as MRI spectroscopy or PMMR diffusion in perinatal death, however these are labor-intensive and contrary to PMCT, PMMRI is often not available for postmortem scanning [ 23 , 24 ].…”

Perinatal and paediatric post-mortem magnetic resonance imaging (PMMR): sequences and technique

“…We recently showed that liver and renal cortex ADC values were lower in PM cases than normal live infants, which may be related to different water content of different organs and their rate of autolysis or decomposition. 35 Lung ADC values were higher, likely to represent fluid accumulation in the lungs following death, since there is no signal obtained from normal aerated lung parenchyma in live infants. Interestingly, there was a significant correlation between lung ADC and post-mortem interval, which could be of interest in medicolegal cases.…”