Value of 3-dimensional sonography for prenatal diagnosis of vertebral formation failure

Objectives - The purposes of this study were to explore the value of 3-dimensional sonography for diagnosis of vertebral formation failure in the developing fetus and to formulate antenatal sonographic diagnostic criteria for suspected vertebral formation failure based on a comparison of sonographic characteristics of the disorder with normal sonographic findings and other imaging data. Methods - This study included sonographic data from 30 healthy fetuses and 13 fetuses suspected to have vertebral formation failure. Three-dimensional reconstruction of sagittal sections of the physiologic curves of the cervicothoracic and lumbosacral regions of the healthy fetuses was performed, and reconstruction was also performed on selected areas of interest when vertebral malformation was suspected. Stored data were analyzed, and a comparison with other image data was performed using various methods. Results - Three-dimensional reconstruction was more suitable for fetal spinal sonography among the 30 healthy fetuses, and it was particularly superior in detecting the positions of spines with evident physiologic curvature. The images revealed suspected vertebral formation failure in 13 cases, and the confirmed findings included 7 cases of hemivertebrae, 2 cases of butterfly vertebrae, 2 cases of mixed malformations (butterfly vertebra and hemivertebra), and 1 case of a coronal cleft vertebra. One case was lost to follow-up. The sonographic characteristics were definite, and there were evident differences from the sonograms of spina bifida. Conclusions - Three-dimensional sonography is helpful for detection of vertebral formation failure in the developing fetus and might provide prognostic information with the potential to ameliorate the progressive spinal deformities that can result from embryonic vertebral formation failure.