Tuberculosis radiology

Radiology (X-rays) is used in the diagnosis of tuberculosis. Abnormalities on chest radiographs may be suggestive of, but are never diagnostic of TB, but can be used to rule out pulmonary TB.

Chest X-ray

thumb|Tuberculosis creates cavities visible in [[x-rays like this one in the patient's right upper lobe.]]

A posterior-anterior (PA) chest X-ray is the standard view used; other views (lateral or lordotic) or CT scans may be necessary.

In active pulmonary TB, infiltrates or consolidations and/or cavities are often seen in the upper lungs with or without mediastinal or hilar lymphadenopathy. However, lesions may appear anywhere in the lungs. In HIV and other immunosuppressed persons, any abnormality may indicate TB or the chest X-ray may even appear entirely normal.

Normal findings

These are films that are completely normal, with no identifiable cardiothoracic or musculoskeletal abnormality.

Abnormal findings

Chest X-ray findings that can suggest active TB

This category comprises all findings typically associated with active pulmonary TB.). The surrounding haziness can be either subtle or readily apparent and suggests coexisting airspace consolidation.

File:Chest X-ray and CT of tree-in-bud sign post-primary pulmonary tuberculosis.jpg|Chest x-ray showing nodule with margins that are indistinct or poorly defined (tree-in-bud sign) in post-primary pulmonary TB.

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<br />4. Pleural effusion - Presence of a significant amount of fluid within the pleural space. This finding must be distinguished from blunting of the costophrenic angle, which may or may not represent a small amount of fluid within the pleural space (except in children when even minor blunting must be considered a finding that can suggest active TB).

File:Pleural effusion of primary pulmonary tuberculosis.jpg|Chest x-ray showing dense opacity pleural effusion in the lower left lung of primary pulmonary TB.

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5. Hilar or mediastinal lymphadenopathy (bihilar lymphadenopathy) - Enlargement of lymph nodes in one or both hila or within the mediastinum, with or without associated atelectasis or consolidation.

File:Chest x-ray of bilateral hilar adenopathy of primary pulmonary tuberculosis.jpg|Chest x-ray showing bilateral hilar adenopathy of primary pulmonary TB

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6. Linear, interstitial disease (in children only) - Prominence of linear, interstitial (septal) markings.

File:Kerley B lines of primary tuberculosis.jpg|Chest x-ray showing Kerley B line due to interstitial oedema (in children only) of primary pulmonary tuberculosis.

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7. Other - Any other finding suggestive of active TB, such as miliary TB. Miliary findings are nodules of millet size (1 to 2 millimeters) distributed throughout the parenchyma.

File:PulmonaryTBCXR.png|Miliary tuberculosis

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Chest X-ray findings that can suggest inactive TB

This category includes findings that are suggestive of prior TB, that is inactive. Assessments of the activity of TB cannot be made accurately on the basis of a single radiograph alone. If there is any question of active TB, sputum smears must be obtained. Therefore, any applicant might have findings grouped in this category, but still have active TB as suggested by the presence of signs or symptoms of TB, or sputum smears positive for AFB.]]

Peritoneal tuberculosis may mimic peritoneal carcinomatosis on CT scan.

References

External links

Additional X-ray images

Chest X-ray Atlas - Select Diseases|Tuberculosis for TB CXR case studies (X-ray pictures showing cavities, infiltrates, scarring, pleural effusion, interstitial nodules of military TB, and TB spine) - from Loyola University Chicago Stritch School of Medicine ©
Teaching File Radiology of Tuberculosis