CT imaging of rapid progression stage. A 50 years old female with anorexia, fatigue, muscle soreness, nasal congestion and runny nose for 1 week, sore and itching throat for 2 days. Laboratory test: increased erythrocyte sedimentation rate (25 mm/h), normal white blood cells (4.08 × 109/L), decreased lymphocytes (0.96 × 109/ L), increased C-reaction protein (60.8 mg/L). Imaging examination: a (thin layer CT) and b (high-resolution CT) showed multiplepatchy and light consolidation in both lungs and grid-like thickness of interlobular septa