Pulmonary Aspiration= Acute Alveolar Edema

Aspiration pneumonia. Lateral radiograph in an 84-year-old patient confirms the location of the abnormality in the left lower lobe.

Aspiration pneumonia. CT scan through the lower-lobe bronchi demonstrates a metallic object in the left lower-lobe bronchus. The patient had aspirated a filling, which had fallen out of one of his teeth. The patient underwent bronchoscopy, and the foreign body was removed. The patient was treated with antibiotics for the pneumonia, which eventually resolved. Incidentally, a small pleural effusion on the right side was due to minimal congestive heart failure (CHF).

Aspiration is defined as entry of a foreign substance, solid or liquid, into the respiratory tract or inhalation of fumes and vapors. Aspiration pneumonia is an infectious process caused by aspirated oropharyngeal flora. Aspiration pneumonitis, which is caused by a direct chemical insult due to the aspirated material, is technically a different entity, but is often referred to as aspiration pneumonia.
The most common predisposing factors for aspiration in adults are alcoholism, stroke and other neuromuscular disorders, seizures, and loss of consciousness.

Chest radiography is readily available and inexpensive and is by far the most commonly used imaging test to evaluate aspiration pneumonia. Traditionally, posteroanterior (PA) and lateral chest radiographs have been recommended for imaging aspiration pneumonia and its complications. However, because many patients are not able to cooperate for PA and lateral imaging, anteroposterior (AP) portable images have been more commonly used for diagnosis.
CT scanning is the best method for diagnosing aspiration pneumonia, an abscess, or an empyema. CT precisely delineates the location of the lobar or segmental opacity. A foreign body in the tracheobronchial tree and associated atelectasis or consolidation can be defined with relative ease on CT scans. Aspiration of specific material such as fat or contrast material can sometimes be determined by measuring the tissue attenuation on CT scans. Esophageal abnormalities may also be seen on CT images without the need for contrast material. Necrosis, cavity formation, and empyema are all complications of aspiration pneumonia that are seen better and earlier with CT than with plain radiography.