Fear of radiation exposure keeps some people from getting a calcium score done for their coronary arteries.

The calcium score is a strong predictor of likelihood of a future heart attack. The equipment used for calcium scoring is the CAT scanner, also known as “CT.”

The amount of radiation delivered during most CT calcium score tests is 2-3 millisieverts up to 8 millisieverts (msvs).

A millisievert is a unit of radiation emission. We are exposed to radiation all around us, and a year’s worth of radiation, in general, amounts to around 3 millisieverts.

You may have heard about a recent study that concludes that the risk of getting cancer from a CT scan is “one in 1,000.”

However, this study leaves several questions, such as how many CT scans would it take to produce this result?

And what about the length of time in between each CT scan? What about age of the patient? What about type of CT scanner (msvs delivered)?

Regarding the one in 1,000 conclusion, “There is no reliable statistic for this and I believe the fear is well-overblown,” says Dr. Larry Santora, MD, cardiologist, medical director of cardiac CT, and medical director of the Vascular and Wellness Center, Saint Joseph Hospital, Orange, CA, and author of “OC Cure for Heart Disease.”

He explains, “That being said, it is wise to adhere to the lowest radiation dose possible. There are various types of CT scanners.

“The premier and fastest scanner for coronary calcium screening is the EBCT ( also called ULTRAFAST CT).”

EBCT stands for electron beam computed tomography.

Dr. Santora continues, “This is the gold standard for coronary calcium screening, the fastest and most accurate, and the lowest radiation dose, about the equivalent of two chest X-rays.

“The standard CT scanners are called a spiral or multi-detector CT scanner, like the ‘64 slice CT,’ which can also be used for calcium screening, but are less accurate and much higher radiation, about 15 to 30 chest X-rays of radiation.”

Dr. Santora’s group at the Orange County Heart Institute has been using only EBCT scanners for coronary calcium scoring for 15+ years.

The Institute, however, uses the 64 slice for CT angiography for the coronary arteries, to measure for possible narrowing and levels of “soft” plaque.

“The cancer risk from an EBCT heart scan is infinitesimally small,” he continues.

How many millisieverts of radiation does an EBCT calcium scoring emit? Six-tenths of a millisievert.

This is less than one dental X-ray, says Dr. Santora, or the equivalent of one abdominal X-ray.

A much lower radiation dose isn’t the only benefit with EBCT.

Dr. Santora explains, “The X-ray beam comes only through the patient from behind throughout the back, whereas regular CT spirals (multi-detector CT like 64 slice) go around.

“The thyroid and breast tissue are the most sensitive organs to radiation, so with EBCT they get very little radiation, while they get a lot with other CT.

“So EBCT is overall less radiation, and the most sensitive organs get a lot less.”

Dr. Santora’s areas of interest include interventional cardiology – coronary stenting, cardiac CT – CT angiography, and coronary calcium screening with EBCT.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  


Top image: Shutterstock/Brian A Jackson