DIAGNOSIS

Tuberculosis diagnosis usually occurs after a combination of skin, blood and imaging tests. The most common diagnostic test is a simple skin test called the Mantoux test.

-The Mantoux test consists of a small amount of purified protein derivative (PPD) tuberculin that is injected into the forearm. After 48 to 72 hours, a doctor or nurse looks for a reaction at the injection site; a hard, raised red bump usually indicates a positive test for TB. Blood tests may also be used to determine whether TB is active or latent (inactive), and a microscopic sputum analyses or cultures can find TB bacteria in the sputum.



This picture shows a person that is tested to be positive for TB. A swell or bump develops at point in which the PPD is injected into the forearm.








While in this picture, this person underwent the mantoux test and was tested negative for TB. As shown, the bump is not so obvious.




-Chest X-rays and computer tomography (CT) scans are also used to diagnose TB. If the immune system traps the TB bacteria and creates scar tissue, this tissue and the lymph nodes may harden like stone in a calcification process. This results in granuloma (rounded marble-like scars) that often appears on x-rays and CT scans. However, if these scars do not show any evidence of calcium on an x-ray, they can be difficult to distinguish from cancer.



These two pictures above shows X-ray scans of the ribcage at different stages of tuberculosis.

The one on the top shows tuberculosis at an early stage while the one on the bottom shows tuberculosis at a late stage.