ct scan/lung nodules

What is the difference between a ct scan w/dye and a PET scan?  Lung nodule found in right lower lobe measuring 1cm.  Don't know what this could be.  Have been a smoker for years.  Quit 4 months ago.  Found out about nodule 2 months ago.  Does anyone have any idea what this could be.

[National Jewish]

A nodule is usually a small, round shadow seen on chest x-ray anywhere in the lungs.  Nodules are due to infections, inflammation, or tumors.  Since the nodule is 1 centimeter in size it is very unlikely to be cancer.  You will need to have more testing done to know what this could be.  A chest CT scan is usually the next test that is done because it is more sensitive and shows more detail than a chest x-ray.  The shape, smoothness, and density of the nodule will be seen on the CT scan.  This will help in determining what this could be.

If you have had previous chest x-rays or CT scans it would be helpful to locate them.  Then your doctor could compare them with your most recent chest x-ray and CT scan.  The comparison could help your doctor to interpret these findings and the significance of the nodule.

In addition to an image that is similar to a CT scan, a positron emission tomography (PET) scan shows biologic activity.  A PET scan is a very accurate test to tell if a nodule is or is not cancer.  However it is not perfect.  This test is less reliable when the nodule is smaller than 1.5 centimeters in size.

The nodule in the right lower lobe of your lung may or may not be related to smoking.  Congratulations on quitting smoking.  Whatever the outcome, you should look upon this as a sign that you should never smoke again.  At this time quitting smoking is the most important thing that you can do for yourself!  Congratulations, you have made a wise decision to stop smoking!  You may want to look at our Quit Smoking Topic Center at http://www.nationaljewish.org/topic/smoking_cessation.html for ways to help you stick with your wise decision to smoke no more.  Also check with your doctor for other quit smoking resources in your area.