Three-dimensional volume-rendered imaging of normal and abnormal fetal fluid-filled structures using inversion mode.

A total of six normal and eight abnormal fetuses at 16-38 weeks of gestation were studied using transabdominal three-dimensional sonography with an inversion mode. In normal fetuses, the stomach, gallbladder and bladder could be depicted. In particular, peristalsis of the stomach was noted. In the case of holoprosencephaly, fused hemispheres were evident. In the case of hydrocephalus, the enlargement of ventricular cavities was noted. In the case of bilateral pleural effusion, the spatial relationship and size of the effusions were depicted. In the case of meconium peritonitis, the spatial relationship between the dilated intestines and ascites was depicted. In two cases of hydronephrosis, the dilated renal pelvis and calyces were clearly shown. In the case of multicystic dysplastic kidney, the number and size of cysts were clearly identified. In the case of left ovarian cyst, the anatomical relationships among the ovarian cyst, kidney, stomach and bladder could be easily understood.