What should you know about a lung cancer scan?

A scan can support a diagnosis, but an image alone does not usually confirm cancer. Your care team may combine the scan with your symptoms, examination, medical history, and sometimes a biopsy.

A chest CT is commonly used because it provides detailed cross-sectional views of the lungs and nearby structures. It may show a nodule, mass, enlarged lymph nodes, fluid around the lung, or another cause for a breathing symptom. Some scans use contrast material to make blood vessels and selected tissues easier to distinguish; the radiology team will check whether this is suitable for you.

Further imaging may examine other parts of the body when clinicians need to understand the extent of disease. A finding outside the lung is not automatically a metastasis, so it needs clinical interpretation and, when appropriate, additional testing. Brain metastases are cancer deposits that have travelled to the brain; symptoms and scan findings are assessed together.

The report may describe the location and appearance of an abnormality and recommend comparison with earlier images or follow-up. Words such as nodule, opacity, or lymph node describe an imaging finding; they do not, by themselves, name its cause. Read more about [Lung Cancer](/conditions/lung-cancer/).

Before the appointment, tell the imaging team about pregnancy or possible pregnancy, allergies or previous reactions to contrast, kidney problems, and medicines you take. Follow the instructions about eating, drinking, or arriving early. Wear clothing that allows easy access to the chest and remove metal items when asked.

During a CT scan, you lie still while the scanner takes images. You may briefly be asked to hold your breath. If contrast is used, you may notice a short-lived warm or unusual taste. Afterward, ask when and how you will receive the report, who will explain it, and whether another test such as a biopsy, PET scan, or genomic tumour profiling is needed.

A scan result guides decisions; it does not decide treatment by itself. Depending on the findings, a team may discuss surgery such as lung lobectomy, radiotherapy, chemotherapy, or other options.

Contact your clinical team promptly if a new or worsening symptom follows the scan or contrast, especially a widespread rash, swelling of the face or throat, wheezing, or difficulty breathing. Seek emergency help for severe breathlessness, blue or grey lips, sudden confusion, fainting, or chest pain that is severe or does not settle.

Do not wait for a routine scan appointment if you are coughing up a large amount of blood, are struggling to breathe at rest, or have sudden weakness, difficulty speaking, or a seizure. A persistent hoarse voice should also be assessed, particularly when it is new or worsening; see [Hoarse Voice](/symptoms/hoarse-voice/) for related information.

Ask what type of scan you are having and what question it is intended to answer. Ask whether contrast is planned, how the result will be reported, and whether an earlier image should be compared. You can also ask what the next step would be if the scan shows a nodule, enlarged lymph nodes, or a change outside the lung.

If cancer is confirmed or strongly suspected, ask how the scan affects staging, whether tissue testing is needed, and whether genomic tumour profiling could guide treatment choices. Ask who will coordinate your results and when you should contact the team.