A pulmonary infiltrate is a substance denser than air, such as pus, blood, or protein, which lingers within the parenchyma of the lungs. Pulmonary infiltrates are associated with pneumonia, tuberculosis, and nocardiosis.
Pulmonary infiltrates in ICU
Xray Interpretation - Infiltrates
[Wikipedia] Pulmonary infiltrate
Pulmonary infiltration of CLL: implications for treatment