Epidemiological and clinical characteristics of fifty-six cases of COVID-19 in Liaoning Province, China

Figure 1 Comparison of lung computed tomography images of a serious case and a mild case. A: Multiple indistinct patchy opacities in both lungs; large areas of ground-glass opacity and consolidative opacity; large areas of consolidative opacity in the basal segments of the lower lobes of both lungs, with air bronchogram visible inside. Lesions are serious in the middle and outer zones [26-year-old male patient, computed tomography (CT) taken on February 2, 2020, the 7^th d after disease onset]; B: A few indistinct patchy opacities in the upper lobe of the left lung, middle lobe and lower lobe of the right lung (47-year-old male patient, CT taken on February 4, 2020, the 5^th d after disease onset).

Figure 2 Progression of pneumonia as observed in the lung computed tomography images of a serious case (51-year-old male patient). A: Multiple small patchy opacities and large areas of ground-glass opacity in both lungs, particularly in the outer zones and under the pulmonary pleurae; larger area of lesion in the basal segment of the lower right lobe, with air bronchogram and vascular thickening visible inside [computed tomography (CT) taken on February 3, 2020, the 7^th d after disease onset]; B: Multiple small patchy opacities and large areas of ground-glass opacity in both lungs, particularly in the middle and outer zones of bilateral lung fields and under the pulmonary pleurae; the lesions have slightly increased in number and size (CT taken on February 5, 2020, the 9^th d after disease onset); C: Multiple small patchy opacities and large areas of ground-glass opacity in both lungs, particularly in the middle and outer zones and under the pulmonary pleurae; new patchy opacities and large areas of ground-glass opacity can be observed in the bilateral lower lobes and the right middle lobe (CT taken on February 10, 2020, the 14^th d after disease onset); D: Multiple small patchy opacities and large areas of ground-glass opacity in both lungs, particularly in the middle and outer zones and under the pulmonary pleurae; the scope of the lesions shows a clear reduction (CT taken on February 17, 2020, the 21^st d after disease onset).

Figure 3 Development of pneumonia as observed on the lung computed tomography images of a mild case (39-year-old male patient). A: Multiple indistinct patchy opacities, ground-glass opacities, and stripe-like opacities in both lungs, particularly in the right lung [computed tomography (CT) taken on February 4, 2020, the 8^th d after disease onset]; B: Multiple indistinct patchy opacities, ground-glass opacities, and stripe-like opacities in both lungs, particularly in the right lung; the lesions show a reduction in size (CT taken on February 7, 2020, the 11^th d after disease onset); C: A few light patchy opacities are scattered in the middle and outer zones of the right upper lobe and bilateral lower lobes; the lesions show a clear reduction in size (CT taken on February 15, 2020, the 19^th d after disease onset).