Post‐mortem apparent resolution of fetal ventriculomegaly: evidence from magnetic resonance imaging

Abstract

Post-mortem examination, both by traditional neuropathological examination, and post-mortem MRI may fail to confirm prenatal ventriculomegaly in around half of cases. The post-mortem MRI findings indicate that this is due to resolution of ventriculomegaly rather than autopsy artefact, and is presumably a consequence of post-mortem fluid redistribution. Parents should be advised before termination of pregnancy that post-mortem confirmation of ventriculomegaly, especially in mild cases, may not be possible. Antenatal MRI may be a better approach for confirming prenatal ultrasound findings.

Diagnostic accuracy and limitations of post-mortem MRI for neurological abnormalities in fetuses and children

“…Such discrepancies between PMMRI and histological brain examination in fetuses has been reported previously, 20 particularly with ventriculomegaly. 21 It should be noted that accurate diagnosis of antemortem ischaemic injury was particularly difficult using PMMRI. Loss of grey and white matter differentiation, loss of the normal high signal intensity in posterior limb of internal capsulae, and white matter T2 prolongation are recognised imaging features of ante-mortem hypoxiceischaemic injury.…”

Is traditional perinatal autopsy needed after detailed fetal ultrasound and post‐mortem MRI?

“…Our study suggests that the main caveat to this statement is ventriculomegaly, where a prenatal diagnosis was neither confirmed by PMMR nor autopsy; this apparent "false positive" imaging finding has been shown to resolve by PMMR and may represent normal post-mortem change, unlikely to benefit from autopsy confirmation. 20 Overall, these data support a potential change in the clinical service, such that PMMR would be offered routinely following perinatal deaths, and autopsy reserved for those in whom there is discordance between prenatal and post-mortem imaging findings. This clearly has widespread economic and service delivery implications, as PMMR Another limitation is in the interpretation and reporting of PMMR and autopsy results.…”

“…We interpret this data to mean that where families wish to avoid invasive methods, the additional benefit of autopsy is likely to be most important where the prenatal US and PMMR findings are partially or completely discordant, and that this should be decided upon by a case‐by‐case basis, depending on likelihood of affecting future pregnancy management. Our study suggests that the main caveat to this statement is ventriculomegaly, where a prenatal diagnosis was neither confirmed by PMMR nor autopsy; this apparent “false positive” imaging finding has been shown to resolve by PMMR and may represent normal post‐mortem change, unlikely to benefit from autopsy confirmation …”

Post-mortem magnetic resonance (PMMR) imaging of the brain in fetuses and children with histopathological correlation

“…cortical malformations), genetic anomalies (mostly karyotype anomalies) or in the presence of intracranial infection and haemorrhage 63 , 64 . Interestingly, VM has been shown to resolve in 50% of cases between the antenatal and post mortem imaging period, although the exact mechanism is unclear, possibly secondary to fluid shifts following death 65 . Nevertheless, it is important to counsel both clinicians and parents prior to post-mortem examination to this fact, as the diagnostic yield may be variable and the purpose of further post-mortem investigation is in determining causes for the VM (and potential predictions for risks of recurrences in future pregnancies) rather than on determining whether VM was present or not 62 .…”