To explore the value of ultrasonography combined with magnetic resonance imaging (MRI) in the clinical diagnosis of fetal cerebral cortex development malformation (MCD).

Retrospectively analyzing the MRI findings of 207 fetuses with brain dysplasia indicated by ultrasonography in Women′s Hospital of Nanjing Medical University from August 2015 to November 2019, and analyzing the causes of missed diagnosis of ultrasonography.

In 207 fetuses, 11 cases were diagnosed with MCD. Nine cases of MCD were indicated by ultrasonography and then confirmed by MRI, including 2 cases of hemimegyria, 1 case of polymicrogyria (PMG), 1 case of anencephaly, 3 cases of microcephaly and 2 cases of fissures. Two cases of MCD were not detected by prenatal ultrasonography, both of which were diagnosed as tuberous sclerosis under the test-tube membrane by MRI due to lateral ventriculomegaly. There were 2 cases with two concurrent MCD, 1 case of hemimegalencephaly, and MRI increased the diagnosis of right parietal lobe fissure. Another case of anencephaly, and MRI increased the diagnosis of gray matter ectopic.

Ultrasonography is an important means to detect fetal MCD. MRI can further confirm the results of ultrasonography and it is an important supplement to ultrasonography. Ultrasonography combined with MRI is of great value in the diagnosis of fetal MCD.