The term "pulmonary infiltrate" is considered a context-dependent, non-specific and imprecise descriptive term when used in radiology reports (plain film or CT).
From a pathophysiological perspective, the term "infiltrate" refers to “an abnormal substance that accumulates gradually within cells or body tissues” or “any substance or type of cell that occurs within or spreads as through the interstices (interstitium and/or alveoli) of the lung, that is foreign to the lung, or that accumulates in greater than normal quantity within it” ref
While when used with a better anatomic reference, such as alveolar, air space, interstitial, or nodular, it may occasionally be helpful in suggesting an underlying pathologic basis for the findings on the radiograph, the use of the term in general is discouraged.
According to a study by Patterson et.al, the use of the term "infiltrate" on its own was not shown to be very meaningful for the clinician or very beneficial to the patient 1.
According to Fleischner Society recommendations, use of the term "infiltrate" remains controversial and is no longer recommended 3.
- 1. Patterson HS, Sponaugle DN. Is infiltrate a useful term in the interpretation of chest radiographs? Physician survey results. Radiology. 2005;235 (1): 5-8. Radiology (full text) - doi:10.1148/radiol.2351020759 - Pubmed citation
- 2. Tuddenham WJ. Glossary of terms for thoracic radiology: recommendations of the Nomenclature Committee of the Fleischner Society. AJR Am J Roentgenol. 1984;143 (3): 509-17. doi:10.2214/ajr.143.3.509 - Pubmed citation
- 3. Hall FM. Fleischner Society glossary of terms: infiltrates. Radiology. 2008;248 (3): 1083. doi:10.1148/radiol.2483080610 - Pubmed citation
- 4. Irwin GA, Motroni B, Gold B. The term infiltrate can be used in reports, if. Radiology. 2005;237 (3): 1122-3. Radiology (full text) - doi:10.1148/radiol.2373050799 - Pubmed citation
- 5. Censullo ML. The "I" word in chest radiography. why is it such a dirty word?. Radiology. 2005;237 (3): 1121. Radiology (full text) - doi:10.1148/radiol.2373050555 - Pubmed citation
- 6. Austin JH, Müller NL, Friedman PJ et-al. Glossary of terms for CT of the lungs: recommendations of the Nomenclature Committee of the Fleischner Society. Radiology. 1996;200 (2): 327-31. Pubmed citation
- 7. Patterson H, Sponaugle D. Drs Patterson and Sponaugle respond:. Radiology. 2005;237 (3): 1124-1124. Radiology (full text) - doi:10.1148/radiol.2373051267