29 Apr, 2024

Lung Cancer X Ray: What Does a Chest X-Ray Show for Lung Cancer?

What is a lung cancer x-ray?

An X-ray is a painless, non-invasive imaging test that uses low-dose radiation to generate two-dimensional detailed images of the body’s internal organs, particularly dense structures such as bones. A lung cancer chest x-ray visualises the lungs, heart, bones of the chest (i.e., rib cage and spinal bones), and blood vessels, revealing any signs of cancer or other lung diseases.

A doctor may order a lung cancer x-ray to evaluate your lung health if you have smoked for a long time or if you are experiencing symptoms such as wheezing, breathlessness, clubbing (widening) of the nails, chest pain, persistent cough or coughing up blood. 

So, how is a chest x-ray for lung cancer done? Depending on the specific view(s) needed, a radiographer (trained X-ray technician) will direct you to sit, stand, or lie down. For standing or sitting images, you will point your shoulder outwards, join your hands and raise them slightly above your head. If lying down on your back, your arms may be placed by your sides or raised above your head. In any case, you will be positioned in front of an X-ray machine. If an extra side-angle image is needed, you will be asked to turn to your side and raise your arms above your head.

During the scan, the machine will send a beam of radiation through your chest to an X-ray detector on the opposite side, which captures an image reflecting the densities of different tissues. Dense tissues absorb a significant amount of radiation and appear solid white or shades of grey, while less dense materials that allow radiation to pass through appear black on X-ray images. Therefore, the bones of your chest will appear white, air in the lungs will appear black, and fluids and soft tissues (e.g., blood vessels, fat, and muscles) will appear in shades of grey.

The entire process is quick, typically taking around 15 minutes, during which the radiographer may instruct you to take a deep breath and hold it for a few seconds to ensure the images are clear and detailed.

What does a chest x-ray show for lung cancer?

To suggest the presence of lung cancer, abnormal chest x-ray images might show an area or growth that differs in density compared to surrounding healthy tissues. But, the details provided by the imaging are usually not sufficient to allow the level of characterization—including analysis of its shape, margin, vascular network (i.e., how it gets blood supply), and cellular activity—that'll determine whether the growth is benign (non-cancerous) or malignant (cancerous). So, on a lung cancer chest x-ray report, an abnormality suspected to be cancerous may be described using any of the following terms:

  • Lung nodule: A small, round or oval-shaped spot on the lung that's under 3 centimetres (approximately 1.2 inches) in diameter.

  • Lung mass: A growth greater than 3 centimetres in diameter.

  • Lung neoplasm: Any new, abnormal growth, be it a lung nodule or mass.

  • Lung lesion: Any type of abnormal tissue in the lung, which can include inflammatory changes, infections, or tumours.

  • Shadow on the lung: An area of increased darkness on the lung, indicating a tumour or simple overlap of normal chest structures.

What does lung cancer look like on x-ray images?

If you’re wondering: ‘How does lung cancer show up on x-ray images?’ The answer is simple. Recall we mentioned how images formed by an X-ray reflect the densities of the different tissues inside the chest. Well, on X-ray images, normal lungs appear dark due to the air filling them, which lets radiation pass through. On the other hand, abnormalities such as fluid, scarring, and tumours (which may or may not be cancerous) are dense and absorb a significant amount of radiation, so they stand out as a light grey or white-coloured mass against the dark background of the air-filled lungs. 

Early lung cancer xray images may show a small, solitary white shadow or spot (nodule). While this shadow could also be due to non-cancerous conditions like cysts or infections, their detection is a crucial first step in diagnosis. In contrast, stage 4 lung cancer xray images may show a more pronounced, hard-to-miss bright mass, as well as multiple irregularities or complications such as spread to different regions within the chest, pleural effusion (fluid buildup around the lungs), blood clots or infections like pneumonia.

Chest x-ray: normal vs abnormal lung cancer results

We asked our Chief Medical Officer, Dr Khalid Latief, who is a consultant radiologist with over 25 years of experience, about the differences between a normal chest x-ray and one that is abnormal and shows lung cancer. He summarised :

‘A normal CXR (chest x-ray) shows lungs as dark because they contain air and no solid tissue. When lung cancer is present you see a ‘shadow’ which is white in appearance on the background of black lungs.‘

While not all shadows on lung x-rays will be cancer, having a shadow in your x-ray images could be a sign that you need further tests or investigations as lung cancer could be present.

How accurate is chest x-ray for lung cancer?

A chest x-ray is highly effective for spotting abnormalities, so it is often the first port of call when lung cancer is suspected. However, it can’t definitively distinguish between cancer and benign masses such as lung abscesses. Therefore, it is used as a preliminary test to determine whether more detailed tests are necessary for further investigation. 

Sometimes, very early lung cancer x-ray images may not reveal any abnormalities at all, creating a false sense of calm—or psychological distress when symptoms persist—and potentially delaying necessary intervention. This missed detection often occurs because early-stage cancer can be smaller than 1.5cm, hide behind bony structures (e.g., the collarbone) or manifest as a small mass or nodule inside the blood vessel and cystic airspaces, which may be missed by X-rays but detected through more sensitive diagnostic tests. Other times, lung cancer may be masked by conditions with similar appearances, such as bronchitis or pneumonia. These commonly occurring situations further emphasise the importance of additional testing. 

What’s the link between pneumonia and early lung cancer x-ray results?

Aside from the fact that lung cancer shares overlapping symptoms with pneumonia, a chest infection which causes inflammation in the lungs, they also appear the same way on X-ray images. Pneumonia often shows up as a white or light grey spot against the black background of the air-filled lungs, similar to early or first-stage lung cancer. Therefore, if pneumonia is diagnosed but does not respond to treatment, further investigation with more advanced imaging tests might be necessary to rule out cancer.

What other tests are there for lung cancer?

A lung cancer xray is only a helpful starting point for what should be a comprehensive diagnostic process. Other detailed tests for lung cancer include:

  • Computed tomography (CT) scan. It is the gold-standard test for diagnosing and staging lung cancer in symptomatic patients and comes highly recommended as an annual screening tool for people at higher risk of the disease.

  • Ultrasound.

  • Magnetic resonance imaging (MRI).

  • Biopsy.

If you are unsure about which scan will be most valuable for identifying the cause of your symptoms and providing information you can trust, consider booking a consultation for £50. You'll match with an expert clinician who will call to discuss your medical history and unique health experience, educate you on the use cases, benefits and risks of the available test options, and offer a no-obligation referral to the scan that's right for your specific needs. If you do decide to book a scan with us, you’ll get a £50 discount on your fee. 

The bottom line

In conclusion, the answer to the question ‘does lung cancer show up on xray?’ is yes. Although, follow-up tests may be required for a definitive diagnosis.

If you're concerned about your lung health, don't wait. Booking a chest X ray today will set you on the fastest track to finding out what’s happening inside your chest and receiving effective treatment. Scan.com is the UK’s largest imaging network. With us, you can browse over 150+ scanning centres nationwide, compare prices, and book the earliest time at a location near you, all in a matter of minutes. No GP referral needed. No long waiting lists. No hidden costs. 



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