Virtual autopsy by computed tomographic angiography of the fetal heart: a feasibility study

Abstract

Objective: To determine the feasibility of postmortem computed tomographic (pm-CT) angiography for fetal heart evaluation.

Methods: Following termination of pregnancy (TOP) or intrauterine fetal death (IUFD) beyond 18 weeks' gestation, 33 fetuses were examined by pm-CT; in eight contrast medium was injected through the umbilical cord and in 25 contrast medium was injected directly into the heart. Logistic regression analysis was used to investigate the effect on the ability to visualize cardiac structures on pm-CT angiography of gestational age at TOP or delivery following IUFD, the time delay between fetal death and examination, the technique used for contrast-medium injection, the presence of cardiac abnormalities and whether or not there was IUFD. The diagnostic accuracy of pm-CT angiography for the evaluation of fetal cardiac structures was also evaluated.

Results: Cardiac anatomy including heart situs, the four-chamber view and great vessels could be visualized on pm-CT angiography in 29 out of 33 fetuses (87.9%). Logistic regression analysis showed that the ability to visualize cardiac structures on pm-CT angiography was positively correlated only with contrast medium injected directly into the heart. Twenty-five out of the 33 fetuses underwent conventional autopsy. There were five cases with suspected major cardiac abnormality at prenatal ultrasound and one with a minor cardiac abnormality. In one of these cases, severe leakage into the pleural cavity did not allow for visualization of any heart structure on pm-CT angiography and in another invasive autopsy was declined. In two of the remaining four cases, the findings on pm-CT angiography and invasive autopsy were in agreement, while in two a ventricular septal defect was found on invasive autopsy but not on pm-CT. None of the 27 cases with normal hearts was falsely classified as abnormal using pm-CT angiography.

Conclusion: Pm-CT angiography by direct injection into the heart seems to be a feasible method for its evaluation. The extent to which such a technique could be used for the evaluation of congenital heart disease as an alternative to classical postmortem autopsy remains to be determined.