Pneumonia - Diagnosis

Chest X-Rays and Other Imaging Techniques

X-Rays. A chest x-ray is nearly always taken to confirm a diagnosis of pneumonia.

X-rays are a form of electromagnetic radiation (like light). They are of higher energy, however, and can penetrate the body to form an image on film. Structures that are dense (such as bone) will appear white, air will be black, and other structures will be shades of gray depending on density. X-rays can provide information about obstructions, tumors, and other diseases, especially when coupled with the use of barium and air contrast within the bowel.

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A chest x-ray may reveal the following:

White areas in the lung called infiltrates, which indicate infection
Complications of pneumonia, including pleural effusions and abscesses

Other Imaging Tests. Computed tomography (CT) scans or magnetic resonance imaging (MRI) scans may be useful in some circumstances, especially when:

X-ray results are unclear
Patients do not respond to antibiotics
Complications occur
Patients have other serious health problems

Click the icon to see an image of a CT scan.

CT and MRI can help detect the presence of tissue damage, abscesses, and enlarged lymph nodes. They can also detect some tumors that block bronchial tubes. No imaging technique can determine the actual organism causing the infection.

Invasive Diagnostic Procedures

Invasive diagnostic procedures may be required when:

Patients have life-threatening complications
Standard treatments have failed for no known reason
AIDS or other immune problems are present

Invasive procedures include:

Thoracentesis. If a doctor detects pleural effusion during the physical exam or on an imaging study, and suspects that empyema (pus) is present, a thoracentesis is performed.

Fluid in the pleura is withdrawn using a long thin needle inserted between the ribs.
The fluid is then sent to the lab for multiple tests.

Complications of this procedure are rare, but include collapsed lung, bleeding, and introduction of infection.

Bronchoscopy. A bronchoscopy is done in the following way:

The patient is given a local anesthetic, supplementary oxygen, and sedatives.
The physician inserts a fiberoptic tube into the lower respiratory tract through the nose or mouth.
The tube acts like a telescope into the body, allowing the physician to view the windpipe and major airways and look for pus, abnormal mucus, or other problems.
The doctor removes specimens for analysis and can also treat the patient by removing any foreign bodies or infected tissue encountered during the process.