Mueller G M, Weiner C P, Yankowitz J
Department of Obstetrics and Gynecology, University of Iowa College of Medicine, Iowa City, USA.
Obstet Gynecol. 1996 Sep;88(3):372-8. doi: 10.1016/0029-7844(96)00207-4.
To test the application of three-dimensional (3-D) ultrasound for the antenatal diagnosis of fetal head and spinal anomalies.
Twenty-five fetuses with head or spinal anomalies and ranging in gestational age from 16 to 33 weeks were studied prospectively: 11 with a control nervous system anomaly (neural tube defect [n = 4], encephalocele [n = 2], hydrocephalus [n = 4], and anencephaly [n = 1]), 13 fetuses with a family history or suspicion of cleft lip or palate, and one with a cloverleaf skull malformation. A volume scan was performed after the two-dimensional examination was complete. The mechanical transducer scans up to 40 degrees in less than 4 seconds, acquiring the data for a pyramid-shaped tissue volume. Three matched and dynamically linked images representing the X, Y, and Z planes are displayed simultaneously. When one image is manipulated, the remaining images are updated automatically to maintain a 90 degrees difference. After the ideal three orthogonal planes are identified, a 3-D image can be reconstructed. A variable number of scan images are possible, depending on the volume size and the data acquisition time. Processing time for the reconstruction depends on volume size, the number of scan images included, and the degrees of rotation of the final image.
The three orthogonal planes proved most helpful delineating the exact nature and anatomic level of the defect. No examination was delayed or required repetition because of suboptimal fetal positioning. The enhanced confidence achieved by our being able to delineate the precise anatomic level and extent of the defect improved patient counseling. The 3-D reconstructions clarified and documented the true magnitude of the defects and on occasion allowed a diagnosis not possible by either two-dimensional or nonreconstructed 3-D imaging.
Our experience with 3-D ultrasound suggests that it is an advance in high-quality ultrasound. Its greatest advantage is that it allows the user to view simultaneously the three orthogonal planes.
测试三维（3-D）超声在胎儿头部和脊柱异常产前诊断中的应用。
对25例孕周为16至33周、患有头部或脊柱异常的胎儿进行前瞻性研究：11例患有对照神经系统异常（神经管缺陷[n = 4]、脑膨出[n = 2]、脑积水[n = 4]和无脑儿[n = 1]），13例胎儿有唇腭裂家族史或疑似唇腭裂，1例患有三叶形颅骨畸形。在二维检查完成后进行容积扫描。机械换能器在不到4秒的时间内扫描达40度，获取金字塔形组织容积的数据。同时显示代表X、Y和Z平面的三个匹配且动态链接的图像。当操作其中一幅图像时，其余图像会自动更新以保持90度的差异。在确定理想的三个正交平面后，即可重建三维图像。根据容积大小和数据采集时间，可以获取不同数量的扫描图像。重建的处理时间取决于容积大小、所包含的扫描图像数量以及最终图像的旋转角度。
三个正交平面在明确缺陷的确切性质和解剖层面方面最有帮助。没有因为胎儿体位不佳而导致检查延迟或需要重复检查。能够明确缺陷的精确解剖层面和范围所带来的信心增强改善了对患者的咨询。三维重建清晰显示并记录了缺陷的真实严重程度，有时还能做出二维或未重建的三维成像无法做出的诊断。
我们在三维超声方面的经验表明，它是高质量超声的一项进步。其最大优势在于允许用户同时查看三个正交平面。
