Association of radiologic findings with mortality of patients infected with 2019 novel coronavirus in Wuhan, China

Abstract

Radiologic characteristics of 2019 novel coronavirus (2019-nCoV) infected pneumonia (NCIP) which had not been fully understood are especially important for diagnosing and predicting prognosis. We retrospective studied 27 consecutive patients who were confirmed NCIP, the clinical characteristics and CT image findings were collected, and the association of radiologic findings with mortality of patients was evaluated. 27 patients included 12 men and 15 women, with median age of 60 years (IQR 47-69). 17 patients discharged in recovered condition and 10 patients died in hospital. The median age of mortality group was higher compared to survival group (68 (IQR 63-73) vs 55 (IQR 35-60), P = 0.003). The comorbidity rate in mortality group was significantly higher than in survival group (80% vs 29%, P = 0.018). The predominant CT characteristics consisted of ground glass opacity (67%), bilateral sides involved (86%), both peripheral and central distribution (74%), and lower zone involvement (96%). The median CT score of mortality group was higher compared to survival group (30 (IQR 7-13) vs 12 (IQR 11-43), P = 0.021), with more frequency of consolidation (40% vs 6%, P = 0.047) and air bronchogram (60% vs 12%, P = 0.025). An optimal cutoff value of a CT score of 24.5 had a sensitivity of 85.6% and a specificity of 84.5% for the prediction of mortality. 2019-nCoV was more likely to infect elderly people with chronic comorbidities. CT findings of NCIP were featured by predominant ground glass opacities mixed with consolidations, mainly peripheral or combined peripheral and central distributions, bilateral and lower lung zones being mostly involved. A simple CT scoring method was capable to predict mortality.

Fig 1. A sample scoring on CT images of a 63-year-old woman from mortality group demonstrated a total score of 63.

It was calculated as: for upper zone (A), 3 (consolidation) × 3 (50–75% distribution) × 2 (both right and left lungs) + 2 (ground glass opacity) ×1 (< 25% distribution) × 2 (both right and left lungs); for middle zone (B), 3 (consolidation) × 2 (25–50% distribution) × 2 (both right and left lungs) + 2 (ground glass opacity) × 2 (25–50% distribution) × 2 (both right and left lungs); for lower zone (C), 3 (consolidation) × (2 (25–50% distribution of the right lung) + 3 (50–75% distribution of the left lung)) + 2 (ground glass opacity) × (2 (25–50% distribution of the right lung) + 1 (< 25% distribution of the left lung)).

Fig 2. Comparison of CT images between survival group and mortality group.

CT images of a 76-year-old woman from survival group showed pure ground glass opacities with predominant peripheral distribution in middle and lower lung zones (A-C). Air bronchogram, together with extensive of consolidations and ground glass opacities were found in the CT images of a 72–year-old woman from mortality group (D-F).

Fig 3. ROC analysis of the CT score for prediction of mortality.

N = 27; AUC = 0.901.

Fig 4. Two cases of CT images from survival group showed ground glass nodular opacities on admission and progressed to multiple patchy ground glass opacities on reexamination.

The CT images of a 60-year-old woman on admission showed peripherally distributed focal ground glass nodular opacities in only right lung (A) and rechecked CT images showed expanded area of patchy ground glass opacities in both right and left lungs with reticular and interlobular septal thickening on 7 days later (B). Unilateral ground glass nodular opacity was found on CT images of a 64-year-old man from survival group (C) and progressed patchy ground glass opacities as well as interlobular septal thickening were seen after 4 days (D).