The usefulness of fetal MRI for prenatal diagnosis

Fast MRI has provided detailed and reproducible fetal anatomy. This study was performed to evaluate the usefulness of fetal MRI for prenatal diagnosis.

Fifty-six fetuses with congenital abnormalities on ultrasonography were evaluated by fetal MRI from 2001 to 2004 in Severance Hospital. Final diagnosis was made by postnatal pathology, postnatal MRI, and other modalities (such as ultrasound, retrograde pyelogram). A 1.5-Tesla superconductive MR imaging unit was used to obtain half-Fourier acquisition single-shot turbo spin images.

Of the 56 fetuses, intracranial abnormalities were found in 26 fetuses, intraabdominal abnormalities in 17 fetuses, intrathoracic in 6 fetuses, head and neck in 5 fetuses, and other sites in 2 fetuses. There were six cases in which the diagnoses of fetal MRI and ultrasonography differed. In such cases, fetal MRI provided more exact diagnosis than ultrasonography (5 vs. 0). Three fetuses with intracranial abnormalities on ultrasonography were diagnosed as normal by fetal MRI and in postnatal diagnosis.

Although ultrasonography is known as a screening modality of choice in the evaluation of fetus because of the cost-effectiveness and safety, the sonographic findings are occasionally inconclusive or insufficient for choosing the proper management. Thus, in this study, we suggest that fetal MRI is more useful than ultrasonography for the evaluation of intracranial abnormalities in some instances. For prenatal counseling and postnatal treatment planning, fetal MRI can be informative when prenatal ultrasonography is inadequate and doubtful.