Types of Pulmonary Tuberculosis Radiology
Tuberculosis (TB) is a contagious bacterial infection that primarily affects the lungs. It is caused by the bacterium Mycobacterium tuberculosis. While many people are aware of the existence of TB, many are not aware of how it manifests in the body. X-rays are an important tool for diagnosing TB and monitoring its progression.
Radiological findings of TB are diverse and can be classified based on their location and appearance:
1. Primary Pulmonary Tuberculosis:
This is the initial infection, often occurring in previously unexposed individuals.
a. Ghon Complex: The most common radiological finding in primary TB. It consists of two components:
- Ghon focus: a small, well-defined, round or oval lesion in the lung parenchyma, usually in the lower lobe.
- Hilar lymph node enlargement: enlarged lymph nodes in the hilum of the lung.
b. Primary Tuberculous Pneumonia: This is a more severe form of primary TB, characterized by consolidation in the lung parenchyma, usually involving the upper lobe. It may also show pleural effusion.
2. Post-Primary Pulmonary Tuberculosis:
This refers to reactivation of a previous TB infection, usually in individuals with a weakened immune system.
a. Cavitary Lesions: The hallmark of post-primary TB. These are well-defined, air-filled cavities in the lung parenchyma, typically located in the upper lobes.
b. Infiltrates: These are areas of increased density in the lung parenchyma, often seen in the upper lobes, indicating inflammation.
c. Tuberculomas: These are well-defined, rounded lesions that are often calcified.
d. Fibrocaseous: This is a form of TB that leads to fibrosis and scarring in the lung.
e. Miliary Tuberculosis: This is a rare form of TB where small, scattered nodules, resembling millet seeds, are present throughout the lungs and other organs.
3. Other Radiological Findings:
- Pleural Effusion: Accumulation of fluid in the space between the lung and the chest wall, often seen in TB.
- Lymph Node Enlargement: Enlarged lymph nodes, particularly in the hilar region and mediastinum.
- Tuberculosis Granulomas: Microscopic, inflammatory nodules that are a characteristic feature of TB infection.
Imaging Techniques:
- Chest X-ray: The most common imaging technique used to diagnose TB. It can reveal various radiological findings.
- Computed Tomography (CT) Scan: Provides more detailed images of the lungs, particularly in identifying cavitary lesions, bronchiectasis, and lymph node involvement.
- Magnetic Resonance Imaging (MRI): Occasionally used for evaluating the extent of TB involvement in the brain or spinal cord.
Limitations of Radiological Findings:
- Radiological findings can be subtle or atypical, especially in early stages of TB.
- Other conditions can mimic TB on radiographs.
- Confirmation of TB requires further investigations, such as sputum culture or molecular tests.
It is important to note that this is a general overview of radiological findings in TB. The specific findings may vary depending on the individual and the stage of infection.
If you suspect TB, seek medical attention immediately for accurate diagnosis and appropriate treatment.
