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Postmortem fetal organ volumetry using magnetic resonance imaging and comparison to organ weights at conventional autopsy
Author(s) -
Breeze A. C. G.,
Gallagher F. A.,
Lomas D. J.,
Smith G. C. S.,
Lees C. C.
Publication year - 2008
Publication title -
ultrasound in obstetrics and gynecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.202
H-Index - 141
eISSN - 1469-0705
pISSN - 0960-7692
DOI - 10.1002/uog.5199
Subject(s) - autopsy , medicine , magnetic resonance imaging , gestational age , fetus , lung , lung volumes , pulmonary hypoplasia , hypoplasia , brain size , receiver operating characteristic , pathology , radiology , nuclear medicine , anatomy , pregnancy , biology , genetics
Objectives Following perinatal death, organ weights at autopsy may provide evidence of growth restriction and pulmonary hypoplasia. Whilst postmortem magnetic resonance imaging (MRI) may provide comparable information to autopsy about structural abnormalities, its ability to provide reproducible data about organ size has yet to be determined. We examined the feasibility of using postmortem MRI to provide estimates of organ size and weight. Methods Twenty‐five fetuses of gestational age from 16 to 40 weeks underwent postmortem MRI prior to autopsy. Fetal lung, brain and liver volume estimations were performed by two observers using the stereology technique on postmortem MRI slices. Fetal lung, brain and liver weights were recorded at autopsy. Organ volume estimates and autopsy organ weights were compared using regression analysis, and estimates of fetal organ densities made. Interobserver variability was assessed using a Bland–Altman plot. Receiver–operating characteristics curve (ROC) analysis compared MRI brain : liver volume ratios to autopsy brain : liver weight ratios. Results A linear relationship between organ volume estimates and organ weight was observed. Estimated densities for the fetal brain, liver and lung were 1.08 g/cm 3 , 1.15 g/cm 3 and 1.15 g/cm 3 , respectively. Interobserver 5 th and 95 th percentile limits of agreement for fetal brain, liver and lung were − 5.4% to + 7.9%, − 11.8% to + 8.3% and − 14.3% to + 8.7%, respectively. For MRI organ volumes to detect a brain weight : liver weight ratio ≥ 4, ROC analysis demonstrated an area under the curve of 0.61, with an optimal cut‐off of 4.1. Conclusion Postmortem MRI organ volumetry can be used to estimate weights of major fetal organs. This may increase the information obtained from a minimally‐invasive perinatal autopsy, particularly in the context of pulmonary hypoplasia and intrauterine growth restriction, where differential organ growth plays a major part in assessment of the underlying pathology. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.