医生安排了一次脑部扫描以调查她头痛的原因。

The doctor ordered a brain ___scan to investigate the cause of her headaches.

约翰陪苏菲去做了一次产前扫描以确定婴儿的性别。

John accompanied Sophie for a prenatal ___scan to determine the baby's sex.

一次常规CT扫描检测出了肺病的早期迹象。

A routine CT ___scan detected early signs of lung disease.