Multiple, patchy, sub-segmental or segmental ground-glass density shadows in both lungs. They were classified as “paving stone-like” changes by fine-grid or small honeycomb-like thickening of interlobular septa. The thinner the CT scan layers, the clearer the ground-glass opacity and thickening of interlobular septa were displayed. A slightly high-density and ground-glass change with fuzzy edge in the fine-grid or small honeycomb-like thickening of interlobular septa were presented by the high-resolution computed tomography (HRCT), (Fig. 1: 45 cases, 54.2% in a total of 83 cases). The resolution of X-ray was worse lower than that of CT in the resolution, which was basically manifested as ground-glass opacities with fuzzy edge (Fig. 2: 9 cases, 10.8% in a total of 83 cases).
Fig. 1 Typical CT imaging manifestation (case 1). A 38 years old male with fever without obvious inducement (39.3 ℃), dry cough and shortness of breath for 3 days. Laboratory test: normal white blood cells (6.35 × 109/L), decreased lymphocytes percentage (4.1%), decreased lymphocytes count (0.31 × 109/L), decreased eosinophil count (0 × 109/L)), increased C-reaction protein (170.91 mg/L), increased procalcitonin (0.45 ng/ml). Imaging examination: multiple patches, grid-like lobule and thickening of interlobular septa, typical “paving stone-like” signs. a SL(Slice): 6 mm; b high-resolution computed tomography(HRCT). HRCT. high-resolution computed tomography
Fig. 2 Typical CT / X-ray imaging manifestation (case 2). A 51 years old male with general muscle ache and fatigue for 1 week, fever for 1 day (39.1 ℃), anemia. Laboratory test: normal white blood cells (9.24 × 109/L), lymphocytes percentage (5.1%), decreased lymphocytes (0.47 × 109/ L), decreased eosinophil count (0 × 109/L), increased C-reaction protein (170.91 mg/L), increased procalcitonin (0.45 ng/ml), increased erythrocyte sedimentation rate (48 mm/h). Imaging examination: a shows patchy shadows in the outer region of the left lower lobe, b shows large ground-glass opacity in the left lower lobe, and c shows subpleural patchy ground-glass opacity in posterior part of right upper lobe and lower tongue of left upper lobe, d shows large ground-glass opacity in the basal segment of the left lower lobe