McGahan J P, Phillips H E, Ellis W G
Radiology. 1983 Apr;147(1):201-3. doi: 10.1148/radiology.147.1.6828729.
A well-demarcated hypoechoic region was seen just lateral to the collicular plate during measurement of the fetal biparietal diameter (BPD) in 101 (70%) of 144 ultrasound examinations and confirmed on postmortem sonographic water-bath studies of fetal brains. This structure was found to represent the hippocampus, with its lateral border formed by the trigone of the lateral ventricle. It should not be confused with an abnormal entity such as a ventricular cyst. Recognition of this hypoechoic region in conjunction with previously described structures is a useful method of obtaining consistent BPD measurements.
在144次超声检查中的101次（70%）测量胎儿双顶径（BPD）时，在丘板外侧可见一个边界清晰的低回声区，并在胎儿脑死后超声水浴研究中得到证实。发现该结构代表海马体，其外侧边界由侧脑室三角区形成。不应将其与异常实体如脑室囊肿相混淆。识别这个低回声区并结合先前描述的结构是获得一致BPD测量值的有用方法。
