It is the build-up of fat, cholesterol, and other substances, called plaque, in and on the artery walls. If there is a lot of buildup, blood flow can be compromised resulting in heart disease and strokes. Sometimes a piece of plaque can rupture off and block off an artery, stopping blood flow to critical organs.
There are two non-invasive tests, still somewhat controversial, that detect the amount of plaque in certain arteries. The first is a Carotid- Intima Media Thickness Test (CIMT) and the other is a cat scan called Coronary Artery Calcium Scan (CAC).

What is a CIMT?

The carotid intima-media thickness test (CIMT) measures the thickness of the inner two layers of the carotid artery and detects plaque on artery walls. It measures your own individual risk.  Sometimes looking at actual evidence of disease and dysfunction and reconciling it with traditional cardiovascular risk markers can be helpful in tailoring and personalizing treatment plans to your individual risk.
PROS:   ~Noninvasive-
~No risk of radiation exposure (uses ultrasound).
~Quick, less than 10 min.
~Can follow results over time to see if treatments are effective.
CONS:  ~Operator dependent- meaning results depend on the technician doing the scan
and the radiologist reading it. There can be discrepancies between providers.
~ May lead to additional (unnecessary) testing, ie if something else that is incidental is
found (like thyroid nodules). Further imaging is often needed.
~What to do with results is still uncertain in many cases.
~Typically not covered by insurance

Who should get a CIMT?

While it is still controversial on how/if to apply this test to the general population, this test is most appropriate for people with no known heart disease, but have risk factors such as: family history of heart disease, cholesterol disorders, high blood pressure, diabetes, and obesity.
A CIMT test is not as helpful for individuals who already have known heart disease or those with very low risk.

What if there is Carotid Plaque?

The presence of plaque in your carotids portends an increased likelihood of a cardiovascular event during the next 10 years compared with those who have no carotid plaque.  The good news is that this can be treated and with aggressive treatment, one can see regression (decrease) of plaque.
Aggressive intervention with life style changes (optimal exercise, nutrition, weight control, and stress management) and/or medication can slow or reverse plaque & carotid thickening.
These interventions CAN DECREASE your risk of having a stroke (and heart disease).

Talk to your health care provider to discuss if a CIMT test is right for you