Ultrasound versus MRI in the diagnosis of fetal head and trunk anomalies.

OBJECTIVE

To compare antenatal sonography and magnetic resonance (MR) imaging (MRI) in the diagnosis of fetal head and trunk anomalies.

METHODS

Forty pregnant women with fetal anomalies on ultrasound (US) examination underwent MRI. The MR examination was done by a radiologist who was provided with the US data. The MR images were then read by one of the two radiologists who were blinded to the US data. They were however told that the region of interest was (1) head-neck or (2) trunk or (3) both. Antenatal US and MRI findings were compared with postnatal diagnosis. Postnatal evaluation included plain radiograph, US, computed tomography, MRI, surgery, physical evaluation and autopsy.

RESULTS

Sixty anomalies were detected in the 40 women studied. This included 36 central nervous system (CNS), 7 thoracic, 7 gastrointestinal, 8 genitourinary and 2 face-neck anomalies. In the evaluation of CNS and thoracic anomalies, more number of confident diagnoses could be obtained by MRI when compared with that by US. In the detection of gastrointestinal and genitourinary anomalies, there was no significant difference between the two modalities.

CONCLUSION

More number of confident diagnoses could be obtained by MRI when compared with that by US, in the evaluation of fetal CNS and thoracic anomalies. MRI can be used in complex fetal anomalies as a supplementary tool following US.