CT Scan of the Chest

A CT scan is medical test that assists physicians in diagnosing and treating a variety of medical conditions. The test is noninvasive, and the entire process of getting the scan only takes about half an hour.

A CT scan uses a combination of high-tech computers and specialized X-ray equipment. This technology is able to produce multiple photos or images of the body's interior, including the bones, internal organs, blood vessels and soft tissue. This scan offers higher clarity and can include more specific details than a standard X-ray.

A variety of techniques allow the radiation amount required for a chest CT scan to be reduced significantly, including new software technology options. The dose can also be altered to reflect the patient's size. A chest CT with a low dose will provide images that can reveal a number of lung diseases and abnormalities. These scans use 65 percent or less ionizing radiation than standard chest CT scans.

Other conditions, such as interstitial lung disease or pulmonary embolism, may not be detected with such a low-dose chest CT. It is up to your radiologist to determine what scan settings should be used for your particular medical problems and the information that needs to be obtained from the CT scan.

Common uses of chest CT results

Chest CT scans are most frequently used for the following:

• Further examination of abnormalities that have been detected through standard chest X-rays or fetal ultrasound examinations
• Diagnosing the cause of symptoms or signs of chest disease, such as a severe cough, chest pain, shortness of breath or fever
• Detection and evaluation of tumors in the chest or determining if tumors have spread to the chest from other body parts
• Assessment of whether tumors are responding to a treatment
• Planning radiation therapy
• Evaluating chest injury, which includes the lungs, ribs, blood vessels and spine

Chest CT scans are also used to identify a number of lung disorders, including the following:

• Bronchietasis
• Old or new pneumonia
• Lung cancer
• Diffuse interstitial lung disease
• Emphysema and other types of obstructive lung disease or COPD
• Tuberculosis
• Inflammation or additional pleura diseases that can cover the lungs
• Abnormalities of a congenital nature

Finally, a CT angiogram (CTA) may be used to assess the chest's blood vessels (also known as the arteries and veins). This process consists of a rapid injection of a fluid that includes an iodine-containing substance into a vein while simultaneously getting CT images.

Preparing for a chest CT scan

When you are preparing for a chest CT scan, you should take the following steps:

• Wear loose, comfortable clothing.
• Leave all metal objects, including glasses, jewelry/piercings, hair pins and dentures, at home or remove them before you begin the scan. If you have removable dental work or hearing aids that contain metal, you will be asked to remove them. Women must take off bras that have metal underwire components.
• Let your technician know if you have a pacemaker.
• Follow all instructions from your physician about how long you must refrain from eating and drinking before the scan.
• Inform your physician of all medications that you currently take; any allergies that you have; any recent medical conditions or illnesses that you've had or currently have; and whether you have any history of asthma, diabetes, heart disease, kidney disease or thyroid problems.
• Inform your physician if there is any possibility of pregnancy.