Main methods for diagnosing tuberculosis

Lung diseases such as tuberculosis are actually very harmful to the health of the lungs. If tuberculosis is not detected and treated in time, it can easily lead to gradual loss of lung function. The main methods for diagnosing pulmonary tuberculosis can be carried out from multiple dimensions, such as sputum tuberculosis examination, chest X-ray examination, immunological diagnosis of pulmonary tuberculosis, etc.

1. Sputum tuberculosis examination:

(1) Sputum smear examination. The sputum tuberculosis test is simple and easy, with high accuracy. If tuberculosis bacteria are found in the sputum, tuberculosis can be confirmed. Generally, three sputum specimens are examined during the first visit to the doctor, namely night sputum, early morning sputum and immediate sputum. Although it is the "golden indicator" for diagnosing pulmonary tuberculosis, its low positive rate is a drawback.

(2) Sputum tuberculosis culture has highly reliable results and can be used for tuberculosis drug sensitivity testing, but it takes 6-8 weeks and its application is limited.

2. X-ray examination Chest X-ray examination can not only detect tuberculosis at an early stage, but also determine the location, nature, and range of the lesions, understand the onset of the disease and judge the effectiveness of treatment. It is easy to carry out and patients are happy to accept it. Chest CT can detect smaller or hidden lesions and make up for the shortcomings of general X-ray examinations.

3. Immunological diagnosis of pulmonary tuberculosis:

1. The commonly used test is the tuberculin purified protein derivative (PPD) test. A positive test is one of the evidences of infection with tuberculosis.

2. Positive tuberculosis antibody test in blood and sputum can also help with diagnosis.

3. Patients with severe pulmonary tuberculosis may have abnormal endocrine examinations.

4. The BACTEC method is used to measure the metabolites of Mycobacterium tuberculosis. Generally, mycobacteria can be isolated within two weeks, but the amount of bacteria can affect the number of days for a positive result to appear.

5. Polymerase chain reaction (PCR) has poor specificity, but its advantage is that its sensitivity can reach 98% to 100%.

IV. Other examinations

1. Fiberoptic bronchoscopy: It can directly observe or indirectly determine bronchial and pulmonary lesions, and has functions such as biopsy, lavage, video recording, and taking photos of the trachea. It is particularly useful for diagnosis and differential diagnosis.

2. Thoracoscopic and mediastinoscopy: Both can be used to observe enlarged lymph nodes in the chest cavity and mediastinum, and biopsies can be taken out to facilitate diagnosis and differential diagnosis.

3. Ultrasonic examination: mainly used for the diagnosis and differential diagnosis of pleural effusion.