A normal chest X-ray result does not completely rule out disease, and the decision for a computed tomography (CT) scan should be carefully considered based on your specific clinical context.

Chest X-rays are widely used for rapid assessment of lung and chest conditions. This method can detect large lesions such as pleural effusion, lung consolidation, and tumors 1-2 cm or larger.

However, X-rays have significant limitations, especially in lung cancer screening. They often miss small nodules or lesions under 1 cm, or those located deep within the lungs. X-ray images also do not provide detailed information about the internal structure of lesions, the lung apex, or the mediastinum.

Somatom Force VB30 CT machine performing a low-dose lung CT scan for lung cancer screening. *Photo: Tam Anh General Hospital*

If you have no respiratory symptoms, no risk factors, and a clinical examination reveals no abnormalities, an additional lung CT scan is not yet necessary.

Conversely, if you belong to a high-risk group – such as long-term smokers, individuals with a family history of lung cancer, those regularly exposed to secondhand smoke, or people working in hazardous environments (asbestos, radiation) – your doctor may recommend a low-dose computed tomography (LDCT) scan for lung cancer screening. This method helps detect lung cancer at a very early stage, when tumors are small and asymptomatic, capable of identifying lesions just a few millimeters in size.

The LDCT technique uses lower X-ray levels compared to conventional CT, is quick to perform, and is non-invasive. Therefore, the risk of harm from radiation exposure during LDCT screening is very low.

If a low-dose CT scan reveals abnormalities, your doctor will recommend further necessary diagnostic tests to reach an accurate conclusion. The decision to undergo a CT scan for lung cancer screening depends on a comprehensive assessment of clinical symptoms, risk factors, and your doctor's recommendation.

Master, Doctor Nguyen Xuan Phong

Imaging Diagnostics Unit

Tam Anh Cau Giay General Clinic