Visualisation of fetal meconium on post-mortem magnetic resonance imaging scans: a retrospective observational study.

BACKGROUND: Less invasive techniques for fetal post-mortems are increasingly used to correlate with parental wishes. With the use of post-mortem magnetic resonance imaging (MRI), normal appearance of the organs must be established. PURPOSE: To investigate the after death appearance of the fetal meconium throughout gestation using the hyperintense appearance of meconium on T1 weighted MRI. MATERIAL AND METHODS: This was a retrospective study that took place in a tertiary referral centre radiology department. Sixty-two fetal body post-mortem MRI scans (January 2014 to May 2018) between 12 and 41 weeks gestation were reviewed. Signal intensity of meconium at the rectum, sigmoid colon, splenic flexure and hepatic flexure was evaluated and correlated with gestational age. Interrater reliability was calculated. RESULTS: Meconium did not consistently have high signal intensity on T1 scans and was not always obvious. Rectal meconium had the highest intensity, and the more proximal the bowel the lower the intensity. The meconium had higher intensity at earlier gestations. Interrater reliability for rectal meconium gradings was excellent. CONCLUSION: This study provides the first published primary research on the appearance of fetal meconium on post-mortem MRI. Overall, results were variable and suggest an alteration of bowel contents after death, but further investigation is needed to effectively inform practice.

Biometric analysis of the foetal meconium pattern using T1 weighted 2D gradient echo MRI.

OBJECTIVES: Foetal MRI is used to assess abnormalities after ultrasonography. Bowel anomalies are a significant cause of neonatal morbidity, however there are little data concerning its normal appearance on antenatal MRI. This study aims to investigate the pattern of meconium accumulation throughout gestation using its hyperintense appearance on T 1 weighted scans and add to the current published data. METHODS: This was a retrospective cohort study in a tertiary referral clinical MRI centre. Foetal body MRI scans of varying gestational ages were obtained dating between October 2011 and March 2018. The bowel was visualised on T 1 weighted images. The length of the meconium and the width of the meconium at the rectum, sigmoid colon, splenic flexure and hepatic flexure was measured. Presence or absence of meconium in the small bowel was noted. Inter- and intrarater reliability was assessed. RESULTS: 181 foetal body scans were reviewed. 52 were excluded and 129 analysed. Visualisation of the meconium in the large bowel became increasingly proximal with later gestations, and small bowel visualisation was greater at earlier gestations. There was statistically significant strong (r = 0.6-0.8) or very strong (r = 0.8-1.0) positive correlation of length and width with increasing gestation. Interrater reliability was moderate to excellent (r = 0.4-1.0). CONCLUSION: This study provides new information regarding the pattern of meconium accumulation throughout gestation. With care, the results can be used in clinical practice to aid diagnosis of bowel pathology. ADVANCES IN KNOWLEDGE: The findings of this study provide further information concerning the normal accumulation of foetal meconium on MR imaging, an area where current research is limited.

Benefits and Limitations of the Minimally Invasive Postmortem: A Review of an Innovative Service Development.

INTRODUCTION: Pediatric postmortem (PM) rates have significantly declined, creating a need for effective minimally invasive alternatives to correlate with parental wishes. We review the use of a minimally invasive fetal and neonatal PM service further to preliminary findings published in 2015. MATERIALS AND METHODS: Cases taken from the mortuary electronic database from 2012 to 2017 are analyzed. The minimally invasive service consisted primarily of external examination, magnetic resonance imaging (MRI), and placental examination. Any significant conditions found noted. All pathology reports include a Relevant Condition at Death (ReCoDe) obstetric classification. Reports analyzed to determine which aspects of the service provided positive information. RESULTS: Of 1498 perinatal postmortems, 105 (7%) were PM MRI, of which 75.24% were intrauterine fetal deaths. Relevant conditions were identified in 94 cases (89.52%), and ReCoDe categories in 80 cases (76.19%). Moreover, 90% of cases had a ReCoDe condition, with 10% unclassified. Seven cases had more than 1 ReCoDe. Main conditions related to placenta (32.5%) and umbilical cord (27.5%). The most informative elements were placental examination and MRI. CONCLUSION: Minimally invasive PMs are a viable alternative to traditional autopsy when this option is refused. However, further case analysis is needed to determine potential bias toward certain classification codes.