MOSAIC ATTENUATION PATTERN ON THIN-SECTION CT SCANS OF THE LUNG - DIFFERENTIATION AMONG INFILTRATIVE LUNG, AIRWAY, AND VASCULAR DISEASES ASA CAUSE

PURPOSE: To determine whether infiltrative lung, airway, or vascular d isease can be differentiated as the cause of mosaic attenuation on thi n-section computed tomographic (CT) scans of the lung. MATERIALS AND M ETHODS: Thin-section CT scans were reviewed in 70 patients examined at three institutions. A mosaic attenuation pattern and pathologic or cl inical proof of a specific type of disease were demonstrated. Causes o f the mosaic pattern included infiltrative lung disease (n = 37), airw ay disease (n = 22), and vascular disease (n = 11). Thin-section CT fi ndings were assessed independently by two observers blinded to clinica l findings. RESULTS: The type of disease was identified correctly at C T in 58 (83%) of 70 patients by observer 1 and 57 (81%) of 70 patients by observer 2. Infiltrative lung disease was diagnosed correctly by b oth observers in 34 (92%) of 37 cases. Observer 1 identified 21 (95%) of 22 cases of airway disease and three (27%) of 11 cases of vascular disease. Observer 2 identified 19 (86%) of 22 cases of airway disease and four (36%) of 11 cases of vascular disease. CONCLUSION: Infiltrati ve lung disease and airway disease may be differentiated reliably as t he cause of mosaic attenuation on lung CT scans, whereas vascular dise ase is often misinterpreted as infiltrative lung disease or airway dis ease.