[High-resolution CT in the differential diagnosis of consolidative processes (I. Acute processes)]

Consolidations are usually result of the replacement of the alveolar air by fluid, cells or tissue but these can also be seen with extensive interstitial processes. These diseases cannot be clearly categorized into the classic classification scheme of airspace and interstitial disease since there are features of both categories seen in the imaging and histologic findings. Because this definition includes wide variety of diseases with overlapping HRCT-findings it is difficult to distinguish among these entities with imaging criteria alone. However, integration of HRCT-findings and clinical findings may enable a narrower differential diagnosis. This review describes the most common types of lung diseases associated with acute appearance of consolidation and discuss the differential diagnosis.