Under What Circumstances Is a CT Scan of the Lungs Necessary?

A computed tomography, or CT, scan of the chest can help doctors to investigate abnormalities found on an X-ray, reports the National Heart, Lung, and Blood Institute. It often helps to identify and evaluate tumors and diagnose the cause of symptoms such as coughing or chest pain.

CT scans are noninvasive tests that provide more detailed information than traditional X-rays, explains the National Heart, Lung, and Blood Institute. They can show the size, shape and condition of the lungs in multiple layers or in a three-dimensional image.

CT scans are powerful diagnostic tools, states the Radiological Society of North America. CT scans of the lungs often help to diagnose lung cancer, tuberculosis, pneumonia and emphysema. The detailed images allow doctors to detect tumors at their smallest, earliest stages. Early detection is one of the greatest weapons in the fight against cancer.

A CT angiogram is a procedure that allows doctors to evaluate veins and arteries in the chest. Technicians take a series of CT images while rapidly injecting a contrast material into the bloodstream, usually an iodine-containing liquid, notes the Radiological Society of North America. This procedure can help to identify blocked areas of a blood vessel or an aneurysm, according to WebMD.

CT scans pose a small amount of risk, notes Mayo Clinic. The radiation can be harmful, especially to pregnant mothers, and some people have reactions to the contrast material. Overall, however, a CT scan is an important tool with low risk involved.