How Can a Chest X-ray Help in Diagnosing Tuberculosis?

Typically, a chest X-ray can identify latent tuberculosis (TB) but not active TB. To confirm a diagnosis in any scenario, a sputum test is required.

Chest X-rays are routinely used by medical professionals to diagnose active tuberculosis (TB).

Mycobacterium tuberculosis (TB) is a dangerous bacterial infection of the respiratory system that can produce a wide range of severe symptoms, including:
  • a long-lasting cough
  • fever
  • chills
  • coughing up blood
On sections of your chest X-ray that are normally clear or translucent, the growth and dissemination of tuberculosis germs can result in observably dense, white patches.

Continue reading to find out more about the use of chest X-rays in the diagnosis of tuberculosis.

Do doctors use X-rays to diagnose tuberculosis?

Depending on whether you have an active or latent (inactive) TB infection, doctors can diagnose you using a variety of tests, including X-rays.

Active TB infection

A physician can identify tuberculosis (TB) by combining several tests, such as a skin test, blood test, and chest X-ray.

To help a doctor identify places in your lungs where TB germs are growing, you will receive a chest X-ray if you have symptoms of tuberculosis (TB) or a positive skin or blood test suggesting a TB infection.

On X-ray scans, areas of TB bacterial infection can appear as white patches called nodules or masses in your lungs, particularly in the upper regions of one or both lungs.

Latent TB infection

On a chest X-ray, tuberculosis (TB) might be hard to find in its latent or early phases.

You might still have tuberculosis bacteria in your body even if your X-ray shows nothing unusual and you don't have any symptoms. It can only be found by a blood or skin test.

To check for any new nodules, a doctor may advise you to have multiple X-rays taken over a predetermined amount of time.

How effective are X-rays in detecting tuberculosis?

Studies indicate that X-rays of the chest can be useful in the diagnosis of pulmonary tuberculosis.

The World Health Organization's 2021 guidelines state that the accuracy of a positive test result for chest X-rays is 85–95% depending on the sensitivity of the scan. Additionally, they have an accuracy percentage of 89–96% for negative test results, or specificity.

When a patient exhibits no symptoms, a TB infection may still be detected by a doctor using blood and skin testing. However, these can occasionally lead to false positives, particularly if you've recently received a TB vaccination. X-ray pictures can give you a better idea of what's happening in your lungs and where a tuberculosis infection might be.

However, a chest X-ray is insufficient to verify a tuberculosis diagnosis. Similar X-ray findings may be the result of other illnesses. Additional testing is required to verify the existence of tuberculosis bacteria.

Other tests for tuberculosis

To verify if TB bacteria are present, medical professionals may employ the following tests:
  • PCR test for polymerase chain reaction
  • sputum smear
  • sputum culture

What do X-ray findings tell us about tuberculosis?

A clinician can identify nodules, lumps, or lesions on a chest X-ray that point to TB bacterial colonies and tissue damage from pathogenic bacteria. Usually, these appear as whiter, brighter areas on your lungs.

A TB infection's dimensions, shape, and density can also be seen with X-rays. A TB infection is typically more progressed in areas with higher white population densities.

Additional signs that a doctor can look for are enlarged hilar lymph nodes. These are lymph nodes close to the wedge-shaped region in the middle of your lung called the hilum.

Miliary TB, a particularly severe form of tuberculosis in which the infection has migrated to other organs, can be identified by several tiny nodules.

Pleural effusion, or an accumulation of fluid surrounding the lungs, is one of the problems that tuberculosis can potentially reveal.

What is the procedure for a chest X-ray for tuberculosis?

The stages involved in a chest X-ray for tuberculosis usually are as follows:
  • You'll walk into a chamber where a big metal arm holds a camera. You will be positioned close to a plate that aids in the capturing of X-ray images by medical staff.
  • To shield you from potentially dangerous radiation, you will put on a lead apron.
  • To take pictures, you will remain motionless and hold your breath as radiation travels through the plate.
An X-ray of the chest typically takes 20 minutes to complete.


One method that can assist in TB detection is a chest X-ray. To screen for tuberculosis infection, doctors can utilise the results of a skin or blood test in addition to the findings from X-rays. Still, a sputum test is required for a precise diagnosis.

If you experience symptoms, especially if you're worried that you may have a tuberculosis infection, consult a physician.


How does a chest x-ray detect tuberculosis?

TB disease in the lungs, also known as pulmonary TB, is the most common form of TB disease

Can X-ray detect pulmonary tuberculosis?

X-ray photofluorography is a relatively expensive way to detect pulmonary tuberculosis

Can you have TB with a negative chest X-ray?

A person has a latent TB infection if they have a positive TB skin test and a normal (negative) chest x-ray.

How do I know if my TB is negative?

If there is no bump (or only a very small bump) at the spot where the fluid was injected.

Post a Comment