Postmortem fetal magnetic resonance imaging: where do we stand?

Abstract

Postmortem fetal magnetic resonance imaging (PMFMRI) is increasingly used thanks to its good overall concordance with histology paralleling the rising incidence of parental refusal of autopsy. The technique could become a routine clinical examination but it needs to be standardized and conducted by trained radiologists. Such radiologists should be aware of not only the (congenital and acquired) anomalies that can involve the fetus, but also of the "physiological" postmortem changes. In this article, we intend to focus on the contribution of PMFMRI based on the existing literature and on our own experience, as we presently perform the technique routinely in our clinical practice.

Key points: • Concordance rates between PMFMRI and autopsy are high for detecting fetal pathologies. • PMFMRI is more acceptable for parents than traditional autopsy. • PMFMRI is becoming widely used as a part of the postmortem investigations. • A dedicated radiologist needs to learn to interpret correctly a PMFMRI. • PMFMRI can be easily realized in daily clinical practice.

Keywords: Autopsy; Fetus; Magnetic resonance imaging; Perinatal; Postmortem.

Figures

Fig. 1

Coronal T1-weighted (W) image of a 24 weeks gestation fetus showing the normal T1 hypersignal of the meconium and thyroid. The fetal liver appears relatively hypersignal, probably due to high glycogen content

Fig. 2

Coronal T2-W image of a 25 weeks fetus in a case of intrauterine death. There is bilateral pleural effusion, subcutaneous edema, ascitis, distended bowel loops, and enlarged appearance of the normal fetal liver. All findings are physiological postmortem changes

Fig. 3

Axial T2-W image of the brain of a 20 weeks fetus showing bilateral intraventricular hemorrhage as a normal postmortem change

Fig. 4

Postmortem fetal magnetic resonance imaging (PMFMRI) in a term stillbirth. Physiological postmortem changes. a Coronal T2-W image showing dark appearance of the lungs containing air. b Axial T2-W image showing air in the hepatobiliary system

Fig. 5

Axial T2-W image of a 23 weeks fetus showing air and blood clots in the heart as a physiological postmortem change. It also shows the normal gray appearance of fetal lungs that have not been aerated

Fig. 6

PMFMRI of a 21 weeks gestation fetus who died in utero. Axial T2-W image shows indirect signs of corpus callosum agenesis. Note that there is a subcutaneous edema that has to be considered as a normal postmortem change

Fig. 7

PMFMRI of a 22 weeks gestation fetus, for which the pregnancy was interrupted for extensive spinal dysraphism. a Axial T2-W image shows bilateral ventriculomegaly. There is a small hemorrhage in the occipital horns that is considered as a postmortem change. b Sagittal T2-W image shows a close spinal dysraphism (asterisk)

Fig. 8

PMFMRI of a 25 weeks gestation fetus in a case of late miscarriage. Sagittal T2-W image shows an occipital encephalocele

Fig. 9

PMFMRI of an 18 weeks gestation fetus in a case of termination of pregnancy. a Sagittal T2-W image shows a megabladder and dilated posterior urethra above the posterior urethral valves (arrow). b Coronal T2-W image shows a right multicystic dysplastic kidney and left hydronephrosis

Fig. 10

Sagittal T2-W image of a 25 weeks gestation fetus with an abdominal wall defect and a large hepatocele

Fig. 11

Coronal T2-W image of a 25 weeks gestation fetus with a left congenial diaphragmatic hernia