Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android

A 78-year-old previously healthy man presented with two days of cough productive of thick purulent sputum, fever and dyspnea on exertion.

On examination, he was an elderly man who appeared acutely ill.

Vital signs—blood pressure 96/60 mm Hg, pulse 116 beats/ min, respiratory rate 24 breaths/min, temperature 103.5°F rectal.

Lung examination revealed scattered ronchi, which were greater on the right than the left.

Blood tests and a chest radiograph were obtained and intravenous antibiotics were administered.

  • What do the chest radiographs show (Figure 1)?

One of the primary roles of chest radiography in emergency department patients is to diagnose pneumonia. Although the chest radiograph is abnormal in nearly all cases, early in its course or with milder cases, the radiograph may be normal. Pneumonia is, therefore, a diagnosis based on clinical, not radiographic, findings. Radiography serves to confirm the diagnosis, to assess prognosis (e.g., poorer outcome with multilobar pneumonia), and to detect an underlying lesion such as a bronchogenic carcinoma causing postobstructive pneumonia.

Pathological Patterns of Pneumonia

There are three pathological patterns of pneumonia: lobar pneumonia, bronchopneumonia (lobular), and interstitial pneumonia. This classification is based on the pathogenesis of the infection and the histological appearance of infected lung tissue. Each pattern is associated with specific infecting organisms (Table 1).

Table 1 Pathological Patterns of Pneumonia

Although these terms are often used to describe the radiographic appearance of pneumonia, there is only limited correlation between the infecting organism and radiographic pattern. For example, pneumococcal pneumonia can have a patchy radiographic appearance simulating bronchopneumonia; staphylococcal pneumonia can cause a relatively uniform segmental consolidation; and viral pneumonia often spreads to the airspaces and has an airspace-filling appearance. Radiographic findings are therefore not used to predict the infecting organism or to choose antibiotic therapy. Antibiotic therapy is based instead on clinical parameters such as severity of illness, host factors such as immunologic status, and clinical setting (community versus hospital acquired).


Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.