My Chest CT Scan FAQ

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1) Do I need to have a chest CT every year for asbestos follow-up?

Chest CT scans give some information on progression of asbestosis, although pulmonary function tests are better. The real value of CT scans is detecting early lung cancers. Asbestos can cause the same kinds of lung cancer as cigarette smoking. Here are the statistics: Compared to a nonsmoker without asbestos exposure, a non-smoker who is heavily exposed to asbestos is at 5 times the risk of getting lung cancer. Compared to a nonsmoker without asbestos exposure, a smoker is at 20 times the risk of getting lung cancer. Compared to a nonsmoker without asbestos exposure, a smoker who is heavily exposed to asbestos is at 90 times the risk of getting lung cancer.

Cigarette smoking does not cause mesothelioma. Mesotheliomas occur in 0.7 per 100,000 people. The risk in workers exposed to asbestos is 2.7 per 100,000 people, over four times as high. I personally believe that the number of mesotheliomas is higher. For one thing, most of my asbestosis patients know someone affected by this disease. In addition, I can name seven celebrities with mesothelioma (football player and actor Merlin Olsen, actor Steve McQueen, Olympic Gold Medalist Terry McCann, former White House Chief of Staff Hamilton Jordan, musician Warren Zevon, actor Paul Gleason and actor Ed Lauter) and I certainly could not list one million celebrities.

2) Isn't radiation from CT scans dangerous?

I believe that the benefits outweigh the risks. The news media has done a disservice to the public. Much of the estimated risk from CT scans rely on cancer rates among the long-term survivors of the atomic bomb blasts in World War II. This is like comparing apples to oranges.

Still, doctors should be concerned about the potential dangers of radiation. The FDA does not regulate how CT scanners are used or set dose limits. So, the medical profession polices itself. Our CT facility receives accreditation from the American College of Radiology, which sets limits for radiation doses and evaluates image quality. In addition, I follow the Fleischner Society Recommendations, which has greatly decreased the number of CT scans done to follow pulmonary nodules (spots on the lung).

A chest CT scan exposes a person to 1.5 to 7 mSv of radiation. We are exposed to that amount of radiation from just living in this world for 6 to 24 months. Radiation is believed to be a more significant risk factor in children.

3) Can I get a chest x-ray instead of a chest CT scan?

Yes. The amount of radiation is less (0.1 mSv) and the cost is less. However, a CT scan is so much better at detecting early cancers than chest X-rays. There is increasing evidence that chest CT scans save lives in patients at risk of lung cancer.

4) What is the significance of coronary artery calcification on a routine CT scan?

This CT finding is of limited usefulness. First, everyone has some buildup of material in the arteries of the heart. Second, a CT scan may or may not detect it. Third, a CT scan cannot really determine how severe the process is.

5) What is the significance of a "ground-glass appearance" on a CT scan?

This simply means an area of haziness. There are a number of possible reasons for this finding. When I encounter this, I make sure the patient does not have symptoms of pneumonia. If not, the ground-glass appearance usually goes away on its own. There is a very slight chance that this could represent an early cancer. I have only seen this happen once since I started practicing in 1989. I usually follow up on this finding with another CT scan of the chest three months.

6) What is the significance of fatty infiltration of the liver on a CT scan?

There are a number of possible reasons for fatty infiltration of the liver including consumption of alcohol, certain drugs, diabetes mellitus and obesity. In and of itself, fatty infiltration of the liver does not cause severe, progressive or lasting liver damage. Usually, this is followed with liver blood tests.

7) What is the significance of kidney cysts on a CT scan?

Kidney cysts are benign fluid-filled spaces. They are found in 27% to 41% of people over the age of 50. Sometimes, an additional test called a renal ultrasound is recommended, but often, no further follow-up is needed.

8) What is the significance of liver cysts on a CT scan?

Liver cysts are benign fluid-filled spaces. They are found in 18% people. Sometimes, an additional test called an abdominal ultrasound is recommended, but often, no further follow-up is needed.

9) What is the significance of kidney stones on a CT scan?

Generally, if kidney stones are causing no symptoms or blockage, treatment is often unnecessary. I tell patients if kidney stones are present since they can cause pain at a later time.

10) What is the significance of gallstones on a CT scan?

Generally, if gallstones are causing no symptoms, treatment is often unnecessary. I was previously told that removal of a gallbladder is sometimes recommended in an asymptomatic diabetic, although is rarely done. I tell patients if gallstones are present since they can cause pain at a later time.