Magnetic resonance imaging of the fetus: initial experience.

Magnetic resonance imaging (MRI) examinations were made on 9 high-risk fetuses (poor fetal growth, 3; maternal manic-depressive psychosis, 1; maternal systemic lupus erythematosus, 1; habitual intrauterine fetal death, 1; twin pregnancy with 1 fetus in distress, 1; fetal hydrocephalus, 1), ranging from 29 to 36 weeks of gestation. T1 weighting sequences were better than T2 weighting sequences for in utero fetal imaging. Fetal movement significantly degraded the imaging quality. In all fetuses, cerebrum, cerebellum, heart, lung, liver, stomach, bladder and extremities were identified and in 1 fetus, even the cochlea was seen. In 2, the four-chamber view of the heart was evident. The signal intensity of the lung was lower than that of the liver in T1 weighting imaging. In the case of maternal lupus erythematosus, a cavum veli interpositi was noted. In the fetus with hydrocephalus, clear images of the intracranial structure were obtained. Similarly, location of the placenta was clearly depicted. MRI is currently less than satisfactory to determine the fetal anatomy, however, it does provide unique and characteristic information that complements the superior anatomic imaging by ultrasonography.