Chest X-ray is a sensitive diagnostic test for inhalation anthrax. Chest X-ray abnormalities associated with inhalation anthrax include mediastinal widening, paratracheal fullness, pleural effusions, parenchymal infiltrates, and mediastinal lymphadenopathy.

• The earliest detectable specific finding indicative of inhalational anthrax is mediastinal widening on posteroanterior chest X-rays. However, mediastinal widening is common in patients presenting at the emergency department.^[1]

• Lymphatic stasis resulting from the damaged lymph nodes leads to dilatation of pulmonary lymphatics which originate in the pleura and drain towards the hilum, following interlobular septa in association with blood vessels. The lymphatic stasis manifests as an early onset pleural effusion and peripheral infiltrates, representing thickened bronchovascular bundles, detectable on chest X-ray. These findings mark fully developed initial stage illness.^[2]

• 
  This right-lateral chest x-ray revealed evidence of a pulmonic infection 4 days after this patient had been exposed to the bacillus, Bacillus anthracis, the cause of the disease known as anthrax. Adapted from Public Health Image Library (PHIL), Centers for Disease Control and Prevention.^[3]
• 
  This right-lateral chest x-ray revealed evidence of a pulmonic infection 13 days after this patient had been exposed to the bacillus, Bacillus anthracis, the cause of the disease known as anthrax. Adapted from Public Health Image Library (PHIL), Centers for Disease Control and Prevention.^[3]
• 
  PA chest radiograph of anthrax, 13th day of illness. Adapted from Public Health Image Library (PHIL), Centers for Disease Control and Prevention.^[3]
• 
  PA chest radiograph of anthrax, 4th day of illness. Adapted from Public Health Image Library (PHIL), Centers for Disease Control and Prevention.^[3]
• 
  This anteroposterior (AP) chest radiograph showed a widened mediastinum due to inhalation anthrax, and was taken 22 hours before death. Adapted from Public Health Image Library (PHIL), Centers for Disease Control and Prevention.^[3]