COVID-19 versus H1N1

COVID-19

versus H1N1: challenges in radiological diagnosis—comparative study on 130 patients using chest HRCT. Mixed parenchymal/alveolar and airway abnormalities seen with H1N1: 47-year-old male H1N1 patient. a Axial HRCT chest lung window with “MIP” reconstruction demonstrating tree in bud nodules (blue arrows) and small ground-glass opacities. b Axial HRCT lung window showing mild bronchiectatic changes with “signet ring sign” (red arrows), patchy areas of mild air trapping (yellow arrows), and tiny few right lower sub-pleural tree in bud nodules (green arrow)

COVID-19

versus H1N1: challenges in radiological diagnosis—comparative study on 130 patients using chest HRCT. Mixed parenchymal/alveolar and airway abnormalities seen with H1N1: 37-year-old male H1N1 patient. a Axial HRCT chest lung window showing right sided mild alveolar ground glass nodular opacities (yellow square). b Axial HRCT lung window showing left lingular zone and to lesser extent right middle lobar air trapping with bronchiectatic changes (blue arrow) and mucous plugging (red arrow)

COVID-19

versus H1N1: challenges in radiological diagnosis—comparative study on 130 patients using chest HRCT. Pure parenchymal/alveolar pattern which cannot differentiate COVID19 from H1N1. a, b 44-year-old-male COVID-19 patient with axial HRCT chest lung window showing bilateral upper and lower lobar peripheral sub-pleural pure ground glass opacities. They shows smooth septal thickening on the right side “Crazy paving pattern” (red arrows). c, d 54-year-old male H1N1 patient with axial HRCT chest lung window showing bilateral upper and lower lobar mainly peripheral and sub-pleural dense ground glass patches

COVID-19

versus H1N1: challenges in radiological diagnosis—comparative study on 130 patients using chest HRCT. Mixed GGOs and “curvilinear organizing pattern of consolidation” seen with COVID-19. a, b 43-year-old female COVID-19 patient with axial HRCT chest lung window showing right sided upper lobar sub-pleural ground glass patchy showing “crazy paving pattern” (orange arrow) and lower lobar sub-pleural curvilinear pattern of organizing consolidation parallel to the pleural lining (yellow arrow)

COVID-19

versus H1N1: challenges in radiological diagnosis—comparative study on 130 patients using chest HRCT. Severe cases complicated by diffuse alveolar damage (DAD), which cannot differentiate COVID19 from H1N1. a, b 52-year-old male COVID-19 patient with axial HRCT chest lung window showing bilateral ground glass opacities, more extensive and dense on the left side showing “crazy paving pattern” and mixed with mild air filled cystic changes denoting “early DAD.” c, d 58-year-old male H1N1 patient with axial and coronal HRCT chest lung window showing bilateral, predominantly upper lobar, ground glass opacity showing “crazy paving pattern” and mixed with air dilled cystic changes denoting “DAD”