Aspiration is defined as entrance of solid or liquid material into the airways or the lungs. It is actually a fairly common phenomenon in which up to 45% of the general healthy population aspirate a small amount of gastric or oral secretion without clinical significance.1 However, in the debilitated population and in people with clinical conditions that predispose them to aspirate frequently and significantly, there can be serious consequences, sometimes life-threatening.
Many risk factors predispose individuals to have large-quantity and/or frequent aspirations. Conditions that impair swallowing and coughing mechanisms include head trauma, stroke, head and neck cancers, seizure, postoperative state, and neuromuscular disorders (i.e., Parkinson disease). Alcoholism is by far the most important factor for aspiration. General anesthesia in nonfasting patients and difficult/emergent intubation may induce gastroesophageal reflux, gagging, or vomiting, which in turn lead to aspiration. Structural and functional abnormalities of the esophagus and pharynx including esophageal stenosis, mass, achalasia, hiatal hernia, gastroesophageal reflux, and tracheoesophageal fistula are all predisposing factors to aspiration.1,2
Diagnosis of aspiration can be difficult because the radiologic manifestations are usually nonspecific and can be confused with several imaging mimickers such as lung cancer, pulmonary edema, pulmonary alveolar proteinosis, and tuberculosis. Therefore, obtaining a good patient history including recent aspiration events and risk factors is a good start on arriving at the correct diagnosis. In this article, we will present a spectrum of radiologic manifestations of aspiration to increase the radiologist's familiarity with this subject, and thus in turn its prompt and accurate diagnosis.