Final answer:
The medical imaging technique that involves an X-ray of the cerebral arteries after contrast injection is known as an angiogram.
Step-by-step explanation:
An X-ray of the cerebral arteries, including the internal carotids, taken after the injection of a contrast medium is called an angiogram. This imaging study is specifically designed to visualize the vasculature of a particular area, most often to detect blockages or abnormalities within the blood vessels. The injection of a contrast medium helps to enhance the image quality, allowing for a clearer depiction of the cerebral arteries.