Assessing the clinical value of foetal MRI for non-CNS abnormalities

Objectives: The purpose of this study was to assess the value of fMRI in addition to prenatal USS in evaluating foetal non-CNS abnormalities and whether information available from the fMRI would change diagnoses or alter patient management and/or counselling thus impacting on clinical care. In addition, the diagnostic accuracy and postnatal impact of both imaging methods was also assessed.
Methods: Both prospective and retrospective assessment of all foetuses in second and third trimesters with suspected non-CNS abnormalities referred to Sheffield Teaching Hospitals for fMRI between November 2011 and February 2020. Two expert panel assessments were performed. The first expert panel analysed scans in an antenatal perspective in order to determine the value of fMRI in shaping patients’ care pathways. The second expert panel analysed scans results in comparison to final postnatal outcome diagnoses for diagnostic accuracy and impact on postnatal care.
Results: Four-hundreds eighty-one foetuses with suspected non-CNS abnormalities were included. Study cohort was divided according to foetal body region involved into six groups. Chest (n=132), GUS (n=142), abdomen (n=128), skeletal (n=43), neck (n=13) and miscellaneous (n=23). Final comparison with postnatal outcome was achieved in 204 foetuses (69 chest, 58 GUS, 52 abdomen, 13 skeletal, 6 neck and 6 miscellaneous cases. Overall (second panel assessment) fMRI had a diagnostic accuracy of 87.7% compared to 69.6% of prenatal USS and it added information in 21.5% that was deemed to have changed diagnoses, management and/or counselling in 7.8% of the foetuses. Both scans diagnostic accuracies varied according to foetal body region with 100% accuracy for both in the neck cohort, chest (fMRI=95.6%, USS=81%), skeletal (fMRI=92%, USS=69%), abdomen (fMRI=88%, USS=69%), miscellaneous (fMRI=83%, USS=66.6%) and GUS (fMRI=75.8%, USS=53%). First expert panel assessment found that fMRI provided additional information in over 60% of the cases and that could have changed the diagnoses, management and/or counselling in 40% of cases.
Conclusion: fMRI provides high diagnostic accuracy in detecting foetal non-CNS pathologies especially foetal chest, abdomen and skeletal abnormalities. It also provides additional useful information to prenatal USS that is useful for clinical management both before and after delivery in all foetal body abnormalities.