Narrowing of the internal carotid artery at the base of the brain, shown by two different techniques.
- Digital subtraction angiography (DSA), a type of x-ray technique used to clearly visualize blood vessels.
- Transcranial color-coded sonography (TCCS), a test that uses ultrasound to measure blood flow in the blood vessels of the brain.
Note: Images are shown for illustrative purposes. Do not attempt to draw conclusions or make diagnoses by
comparing these images to other medical images, particularly your own. Only qualified physicians should interpret images;
the radiologist is the physician expert trained in