[Classical patterns of interstitial lung diseases].

BACKGROUND: High resolution computed tomography (HRCT) is the most important non-invasive tool in the diagnostics and follow-up of patients with interstitial lung disease (ILD).
OBJECTIVES: A systematic review of the HRCT patterns of ILD was carried out and the most relevant differential diagnoses are discussed in order to provide a road map for the general radiologist to successfully navigate the complex field of ILD.
RESULTS: Using HRCT four basic patterns of ILD can be identified: linear and reticular patterns, the nodular pattern, the high attenuation and low attenuation patterns. These patterns can be further differentiated according to their localization within the secondary pulmonary lobule (SPL), e.g. centrilobular or perilymphatic and their distribution within the lungs (e.g. upper or lower lobe predominance). Relevant clinical data, such as smoking history and course of the disease provide useful additional information in the diagnosis of ILD.
CONCLUSION: On the basis of the pattern and anatomical distribution on HRCT, an accurate diagnosis can be achieved in some cases of ILD; however, due to morphological and clinical overlap the final diagnosis of many ILDs requires close cooperation between clinicians, radiologists and pathologists.