Fetal postmortem imaging: an overview of current techniques and future perspectives

Area of Science:

• Medical Imaging
• Pathology
• Perinatal Medicine

Background:

• Fetal death investigations are crucial for parental counseling and understanding recurrence risks.
• Conventional autopsy, while the gold standard, faces challenges including parental consent issues (50-60% acceptance) and autolysis affecting central nervous system examination.
• Noninvasive perinatal virtual autopsy using imaging techniques has emerged as a vital alternative.

Purpose of the Study:

• To evaluate the diagnostic accuracy and limitations of various noninvasive imaging techniques for postmortem fetal examination.
• To propose a novel, stepwise diagnostic approach integrating these imaging modalities.
• To discuss the clinical application of these techniques to reduce parental distress and pathologist workload.

Main Methods:

• Review and analysis of postmortem magnetic resonance imaging (MRI), ultrasound, and computed tomography (CT) techniques.
• Comparison of imaging findings with conventional autopsy results.
• Assessment of parental acceptance rates and diagnostic yields for each imaging modality.

Main Results:

• Postmortem MRI (1.5T) shows 77%-94% diagnostic accuracy for fetuses >20 weeks gestation, with low non-diagnostic rates (<10%).
• Postmortem ultrasound offers 67%-77% sensitivity and 74%-90% specificity but has higher non-diagnostic rates (17-30%).
• Microfocus CT demonstrates near 100% agreement with autopsy for fetuses ≤20 weeks gestation.

Conclusions:

• Noninvasive perinatal imaging techniques, particularly MRI and microfocus CT, provide valuable diagnostic information in fetal death investigations.
• These methods achieve high parental acceptance and can serve as alternatives or adjuncts to conventional autopsy.
• Overcoming hurdles like specialized training and funding is essential for the widespread adoption of these advanced techniques.