What it is
A low-frequency probe placed on the temples and at the base of the skull measures blood velocity in the cerebral arteries through the areas where the bone is thinnest.
At the practice the test is performed without microbubble contrast and therefore does not include screening for a patent foramen ovale.
What it is used for
It detects narrowing of the intracranial arteries, assesses collateral circulation in significant carotid stenosis and completes the vascular work-up after a TIA or stroke.
How it is performed
The patient lies or sits; the probe is placed with gel on the temples and at the base of the skull.
Preparation
- No preparation.
- Take your usual medicines.
Report
The report is written by the doctor who performs the test.
Frequently asked questions
Does it work for everyone?
In some people, especially older adults, the temporal bone is too thick for ultrasound to pass and the test may be incomplete.
What is the microbubble study?
It is a variant used to look for a patent foramen ovale, a communication between the atria of the heart; it is not performed at the practice.
Does it replace an MRI?
No: it measures blood flow, whereas MRI and CT angiography show the anatomy of the vessels and brain.