Tuberculosis radiology

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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.

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Chest X-ray

Tuberculosis creates cavities visible in x-rays like this one in the patient's right upper lobe. TB CXR.jpg
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.[ citation needed ]

In active pulmonary TB, infiltrates or consolidations and/or cavities are often seen in the upper lungs with or without mediastinal or hilar lymphadenopathy. [1] 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. [1]

Old healed tuberculosis usually presents as pulmonary nodules in the hilar area or upper lobes, with or without fibrotic scars and volume loss. [1] Bronchiectasis and pleural scarring may be present.[ citation needed ]

Nodules and fibrotic scars may contain slowly multiplying tubercle bacilli with the potential for future progression to active tuberculosis. [1] Persons with these findings, if they have a positive tuberculin skin test reaction, should be considered high-priority candidates for treatment of latent infection regardless of age. Conversely, calcified nodular lesions (calcified granuloma) pose a very low risk for future progression to active tuberculosis.[ citation needed ]

Abnormalities on chest radiographs may be suggestive of, but are never diagnostic of, TB. [1] However, if a person has a positive response to the tuberculin skin test and no symptoms of the disease, chest radiographs can be used to rule out the possibility of pulmonary TB.[ citation needed ]

CDC guidelines for evaluating CXR

The chest X-ray and classification worksheet by the Centers for Disease Control and Prevention (CDC) of the United States is designed to group findings into categories based on their likelihood of being related to TB or non-TB conditions needing medical follow-up. [2]

Normal findings

These are films that are completely normal, with no identifiable cardiothoracic or musculoskeletal abnormality.[ citation needed ]

Abnormal findings

Chest X-ray findings that can suggest active TB

This category comprises all findings typically associated with active pulmonary TB. [2] In the US, refugees or immigration applicants with any of the following findings must submit sputum specimens for examination. [2]

1. Infiltrate or consolidation - Opacification of airspaces within the lung parenchyma. Consolidation or infiltrate can be dense or patchy and might have irregular, ill-defined, or hazy borders.

2. Any cavitary lesion - Lucency (darkened area) within the lung parenchyma, with or without irregular margins that might be surrounded by an area of airspace consolidation or infiltrates, or by nodular or fibrotic (reticular) densities, or both. The walls surrounding the lucent area can be thick or thin. Calcification can exist around a cavity.

3. Nodule with poorly defined margins - Round density within the lung parenchyma, also called a tuberculoma. Nodules included in this category are those with margins that are indistinct or poorly defined (tree-in-bud sign [3] ). The surrounding haziness can be either subtle or readily apparent and suggests coexisting airspace consolidation.


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).

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.

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

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.

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. [2]

The main chest X-ray findings that can suggest inactive TB are: [2]

1. Discrete fibrotic scar or linear opacity—Discrete linear or reticular densities within the lung. The edges of these densities should be distinct and there should be no suggestion of airspace opacification or haziness between or surrounding these densities. Calcification can be present within the lesion and then the lesion is called a "fibrocalcific" scar.

2. Discrete nodule(s) without calcification—One or more nodular densities with distinct borders and without any surrounding airspace opacification. Nodules are generally round or have rounded edges. These features allow them to be distinguished from infiltrates or airspace opacities. To be included here, these nodules must be noncalcified. Nodules that are calcified are included in the category "OTHER X-ray findings, No follow-up needed".

3. Discrete fibrotic scar with volume loss or retraction—Discrete linear densities with reduction in the space occupied by the upper lobe. Associated signs include upward deviation of the fissure or hilum on the corresponding side with asymmetry of the volumes of the two thoracic cavities.

4. Discrete nodule(s) with volume loss or retraction—One or more nodular densities with distinct borders and no surrounding airspace opacification with reduction in the space occupied by the upper lobe. Nodules are generally round or have rounded edges.

5. Other—Any other finding suggestive of prior TB, such as upper lobe bronchiectasis. Bronchiectasis is bronchial dilation with bronchial wall thickening.

Other chest X-ray findings

Follow-up needed

This category includes findings that suggest the need for a follow-up evaluation for non-TB conditions. [2]

  1. Musculoskeletal abnormalities - New bony fractures or radiographically apparent bony abnormalities that need follow-up.
  2. Cardiac abnormalities - Cardiac enlargement or anomalies, vascular abnormalities, or any other radiographically apparent cardiovascular abnormality of significant nature to require follow-up.
  3. Pulmonary abnormalities - Pulmonary finding of a non-TB nature, such as a mass, that needs follow-up.
  4. Other - Any other finding that the panel physician believes needs follow-up, but is not one of the above.

No follow-up needed

This category includes findings that are minor and not suggestive of TB disease. These findings require no follow-up evaluation. [2]

Chest x-ray of pleural thickening post-primary tuberculosis Chest x-ray of pleural thickening post-primary tuberculosis.jpg
Chest x-ray of pleural thickening post-primary tuberculosis
  1. Pleural thickening - Irregularity or abnormal prominence of the pleural margin, including apical capping (thickening of the pleura in the apical region). Pleural thickening can be calcified.
  2. Diaphragmatic tenting - A localized accentuation of the normal convexity of the hemidiaphragm as if "pulled upwards by a string."
  3. Blunting of costophrenic angle (in adults)—Loss of sharpness of one or both costophrenic angles. Blunting can be related to a small amount of fluid in the pleural space or to pleural thickening and, by itself, is a non-specific finding (except in children, when even minor blunting may suggest active TB). In contrast a large pleural effusion, or the presence of a significant amount of fluid in the pleural space, may be a sign of active TB at any age.
  4. Solitary calcified nodules or granuloma - Discrete calcified nodule or granuloma, or calcified lymph node. The calcified nodule can be within the lung, hila, or mediastinum. The borders must be sharp, distinct, and well defined. This was considered a Class B3 TB in the past; however, Class B3 has been omitted from the classification scheme because it has not been found to be associated with active TB.
  5. Minor musculoskeletal findings - Minor findings needing no follow-up.
  6. Minor cardiac findings - Minor findings needing no follow-up.

Extrapulmonary tuberculosis

CT scan of peritoneal tuberculosis, a form of extrapulmonary tuberculosis. The omentum and peritoneal surfaces are thickened (arrows). CT of peritoneal tuberculosis.jpg
CT scan of peritoneal tuberculosis, a form of extrapulmonary tuberculosis. The omentum and peritoneal surfaces are thickened (arrows).

Peritoneal tuberculosis may mimic peritoneal carcinomatosis on CT scan. [4]

There is low-quality evidence that abdominal ultrasound has 63% sensitivity and 68% specificity in diagnosing abdominal tuberculosis when tuberculosis is bacteriologically confirmed in HIV-positive individuals. Therefore, a negative abdominal ultrasound finding does not rule out the disease due to its low sensitivity. [5]

Related Research Articles

<span class="mw-page-title-main">Pleural effusion</span> Accumulation of excess fluid in the pleural cavity

A pleural effusion is accumulation of excessive fluid in the pleural space, the potential space that surrounds each lung. Under normal conditions, pleural fluid is secreted by the parietal pleural capillaries at a rate of 0.6 millilitre per kilogram weight per hour, and is cleared by lymphatic absorption leaving behind only 5–15 millilitres of fluid, which helps to maintain a functional vacuum between the parietal and visceral pleurae. Excess fluid within the pleural space can impair inspiration by upsetting the functional vacuum and hydrostatically increasing the resistance against lung expansion, resulting in a fully or partially collapsed lung.

<span class="mw-page-title-main">Silicosis</span> Pneumoconiosis caused by inhalation of silica, quartz or slate particles

Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. It is marked by inflammation and scarring in the form of nodular lesions in the upper lobes of the lungs. It is a type of pneumoconiosis. Silicosis is characterized by shortness of breath, cough, fever, and cyanosis. It may often be misdiagnosed as pulmonary edema, pneumonia, or tuberculosis. Using workplace controls, silicosis is almost always a preventable disease.

<span class="mw-page-title-main">Atelectasis</span> Collapse or closure of a lung resulting in reduced or absent gas exchange

Atelectasis is the collapse or closure of a lung resulting in reduced or absent gas exchange. It is usually unilateral, affecting part or all of one lung. It is a condition where the alveoli are deflated down to little or no volume, as distinct from pulmonary consolidation, in which they are filled with liquid. It is often called a collapsed lung, although that term may also refer to pneumothorax.

<span class="mw-page-title-main">Tuberculosis diagnosis</span>

Tuberculosis is diagnosed by finding Mycobacterium tuberculosis bacteria in a clinical specimen taken from the patient. While other investigations may strongly suggest tuberculosis as the diagnosis, they cannot confirm it.

<span class="mw-page-title-main">Chest radiograph</span> Projection X-ray of the chest

A chest radiograph, called a chest X-ray (CXR), or chest film, is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common film taken in medicine.

<span class="mw-page-title-main">Miliary tuberculosis</span> Medical condition

Miliary tuberculosis is a form of tuberculosis that is characterized by a wide dissemination into the human body and by the tiny size of the lesions (1–5 mm). Its name comes from a distinctive pattern seen on a chest radiograph of many tiny spots distributed throughout the lung fields with the appearance similar to millet seeds—thus the term "miliary" tuberculosis. Miliary TB may infect any number of organs, including the lungs, liver, and spleen. Miliary tuberculosis is present in about 2% of all reported cases of tuberculosis and accounts for up to 20% of all extra-pulmonary tuberculosis cases.

<span class="mw-page-title-main">Hypersensitivity pneumonitis</span> Medical condition

Hypersensitivity pneumonitis (HP) or extrinsic allergic alveolitis (EAA) is a syndrome caused by the repetitive inhalation of antigens from the environment in susceptible or sensitized people. Common antigens include molds, bacteria, bird droppings, bird feathers, agricultural dusts, bioaerosols and chemicals from paints or plastics. People affected by this type of lung inflammation (pneumonitis) are commonly exposed to the antigens by their occupations, hobbies, the environment and animals. The inhaled antigens produce a hypersensitivity immune reaction causing inflammation of the airspaces (alveoli) and small airways (bronchioles) within the lung. Hypersensitivity pneumonitis may eventually lead to interstitial lung disease.

Caplan's syndrome is a combination of rheumatoid arthritis (RA) and pneumoconiosis that manifests as intrapulmonary nodules, which appear homogeneous and well-defined on chest X-ray.

<span class="mw-page-title-main">Root of the lung</span>

The root of the lung is a group of structures that emerge at the hilum of each lung, just above the middle of the mediastinal surface and behind the cardiac impression of the lung. It is nearer to the back than the front. The root of the lung is connected by the structures that form it to the heart and the trachea. The rib cage is separated from the lung by a two-layered membranous coating, the pleura. The hilum is the large triangular depression where the connection between the parietal pleura and the visceral pleura is made, and this marks the meeting point between the mediastinum and the pleural cavities.

<span class="mw-page-title-main">Usual interstitial pneumonia</span> Medical condition

Usual interstitial pneumonia (UIP) is a form of lung disease characterized by progressive scarring of both lungs. The scarring (fibrosis) involves the pulmonary interstitium. UIP is thus classified as a form of interstitial lung disease.

<span class="mw-page-title-main">High-resolution computed tomography</span> Diagnostic imaging test

High-resolution computed tomography (HRCT) is a type of computed tomography (CT) with specific techniques to enhance image resolution. It is used in the diagnosis of various health problems, though most commonly for lung disease, by assessing the lung parenchyma. On the other hand, HRCT of the temporal bone is used to diagnose various middle ear diseases such as otitis media, cholesteatoma, and evaluations after ear operations.

<span class="mw-page-title-main">Pulmonary laceration</span> Medical condition

A pulmonary laceration is a chest injury in which lung tissue is torn or cut. An injury that is potentially more serious than pulmonary contusion, pulmonary laceration involves disruption of the architecture of the lung, while pulmonary contusion does not. Pulmonary laceration is commonly caused by penetrating trauma but may also result from forces involved in blunt trauma such as shear stress. A cavity filled with blood, air, or both can form. The injury is diagnosed when collections of air or fluid are found on a CT scan of the chest. Surgery may be required to stitch the laceration, to drain blood, or even to remove injured parts of the lung. The injury commonly heals quickly with few problems if it is given proper treatment; however it may be associated with scarring of the lung or other complications.

<span class="mw-page-title-main">Lung nodule</span> Medical condition

A lung nodule or pulmonary nodule is a relatively small focal density in the lung. A solitary pulmonary nodule (SPN) or coin lesion, is a mass in the lung smaller than three centimeters in diameter. A pulmonary micronodule has a diameter of less than three millimetres. There may also be multiple nodules.

<span class="mw-page-title-main">Fibrothorax</span> Medical condition involving fibrosis of the pleural space

Fibrothorax is a medical condition characterised by severe scarring (fibrosis) and fusion of the layers of the pleural space surrounding the lungs resulting in decreased movement of the lung and ribcage. The main symptom of fibrothorax is shortness of breath. There also may be recurrent fluid collections surrounding the lungs. Fibrothorax may occur as a complication of many diseases, including infection of the pleural space known as an empyema or bleeding into the pleural space known as a haemothorax.

The ILO International Classification of Radiographs of Pneumoconioses is a system of classifying chest radiographs (X-rays) for persons with a form of pneumoconiosis. The intent is to provide a standardized, uniform method of interpreting and describing abnormalities in chest x-rays that are thought to be caused by prolonged dust inhalation. In use, it provides a system for both epidemiological comparisons of many individuals exposed to dust and evaluation of an individual's potential disease relative to established standards.

Rheumatoid lung disease is a disease of the lung associated with RA, rheumatoid arthritis. Rheumatoid lung disease is characterized by pleural effusion, pulmonary fibrosis, lung nodules and pulmonary hypertension. Common symptoms associated with the disease include shortness of breath, cough, chest pain and fever. It is estimated that about one quarter of people with rheumatoid arthritis develop this disease, which are more likely to develop among elderly men with a history of smoking.

<span class="mw-page-title-main">Ground-glass opacity</span> Radiologic sign on radiographs and computed tomography scans

Ground-glass opacity (GGO) is a finding seen on chest x-ray (radiograph) or computed tomography (CT) imaging of the lungs. It is typically defined as an area of hazy opacification (x-ray) or increased attenuation (CT) due to air displacement by fluid, airway collapse, fibrosis, or a neoplastic process. When a substance other than air fills an area of the lung it increases that area's density. On both x-ray and CT, this appears more grey or hazy as opposed to the normally dark-appearing lungs. Although it can sometimes be seen in normal lungs, common pathologic causes include infections, interstitial lung disease, and pulmonary edema.

<span class="mw-page-title-main">Asbestos-related diseases</span> Medical condition

Asbestos-related diseases are disorders of the lung and pleura caused by the inhalation of asbestos fibres. Asbestos-related diseases include non-malignant disorders such as asbestosis, diffuse pleural thickening, pleural plaques, pleural effusion, rounded atelectasis and malignancies such as lung cancer and malignant mesothelioma.

Equine multinodular pulmonary fibrosis is a chronic lung disease of horses. There is evidence that the disease is caused by infection with a gammaherpesvirus, equine herpesvirus 5. The disease affects usually adult horses reducing the ability to exercise as a result of the formation of nodular lesions in the lungs.

Thoracic endometriosis is a rare form of endometriosis where endometrial-like tissue is found in the lung parenchyma and/or the pleura. It can be classified as either pulmonary, or pleural, respectively. Endometriosis is characterized by the presence of tissue similar to the lining of the uterus forming abnormal growths elsewhere in the body. Usually these growths are found in the pelvis, between the rectum and the uterus, the ligaments of the pelvis, the bladder, the ovaries, and the sigmoid colon. The cause is not known. The most common symptom of thoracic endometriosis is chest pain occurring right before or during menstruation. Diagnosis is based on clinical history and examination, augmented with X-ray, CT scan, and magnetic resonance imaging of the chest. Treatment options include surgery and hormones.

References

  1. 1 2 3 4 5 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; & Mitchell, Richard N. (2007). Robbins Basic Pathology (8th ed.). Saunders Elsevier. pp. 516-522 ISBN   978-1-4160-2973-1
  2. 1 2 3 4 5 6 7 "Instructions to Panel Physicians for Completing New U.S. Department of State MEDICAL EXAMINATION FOR IMMIGRANT OR REFUGEE APPLICANT (DS-2053) and Associated WORKSHEETS (DS-3024, DS-3025, and DS-3026)" (PDF). visa-21.com. Centers for Disease Control and Prevention.
  3. ↑ Rossi, S. E.; Franquet, T.; Volpacchio, M.; Gimenez, A.; Aguilar, G. (1 May 2005). "Tree-in-Bud Pattern at Thin-Section CT of the Lungs: Radiologic-Pathologic Overview". Radiographics. 25 (3): 789–801. doi:10.1148/rg.253045115. PMID   15888626 . Retrieved 28 May 2012.
  4. 1 2 Akce, Mehmet; Bonner, Sarah; Liu, Eugene; Daniel, Rebecca (2014). "Peritoneal Tuberculosis Mimicking Peritoneal Carcinomatosis". Case Reports in Medicine. 2014: 1–3. doi: 10.1155/2014/436568 . ISSN   1687-9627. PMC   3970461 . PMID   24715911. CC-BY 3.0
  5. ↑ Van Hoving DJ, Griesel R, Meintjes G, Takwoingi Y, Maartens G, Ochodo EA (30 September 2019). "Abdominal ultrasound for diagnosing abdominal tuberculosis or disseminated tuberculosis with abdominal involvement in HIV-positive individuals". Cochrane Database of Systematic Reviews. 2019 (9): CD012777. doi:10.1002/14651858.CD012777.pub2. PMC   6766789 . PMID   31565799.

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