Predictive value of CT imaging findings in COVID-19 pneumonia at the time of first-screen regarding the need for hospitalization or intensive care unit

Abstract

Purpose: In this study, we aimed to reveal the relationship between initial lung parenchymal involvement patterns and the subsequent need for hospitalization and/or intensive care unit admission in coronavirus disease 2019 (COVID-19) positive cases.

Methods: Overall, 231 patients diagnosed with COVID-19 as proven by PCR were included in this study. Based on the duration of hospitalization, patients were divided into three groups as follows: Group 1, patients receiving outpatient treatment or requiring hospitalization <7 days; Group 2, requiring hospitalization ≥7 days; Group 3, patients requiring at least 1 day of intensive care at any time. Chest CT findings at first admission were evaluated for the following features: typical/atypical involvement of the disease, infiltration patterns (ground-glass opacities, crazy-paving pattern, consolidation), distribution and the largest diameters of the lesions, total lesion numbers, number of affected lung lobes, and affected total lung parenchyma percentages. The variability of all these findings according to the groups was analyzed statistically.

Results: In this study, 172 patients were in Group 1, 39 patients in Group 2, and 20 patients in Group 3. The findings obtained in this study indicated that there was no statistically significant difference in ground-glass opacity rates among the groups (p = 0.344). The rates of crazy-paving and consolidation patterns were significantly higher in Groups 2 and 3 than in Group 1 (p = 0.001, p = 0.002, respectively). The rate of right upper, left upper lobe, and right middle lobe involvements as consolidation pattern was significantly higher in Group 3 than in Group 1 (p = 0.148, p = 0.935, p = 0.143, respectively). A statistically significant difference was also found between the affected lobe numbers, total lesion numbers, the diameter of the largest lesion, and the affected lung parenchyma percentages between the groups (p = 0.001). The average number of impacted lobes in Group 1 was 2; 4 in Group 2 and Group 3. The mean percentage of affected lung parenchyma percentage was 25% in Group 1 and Group 2, and 50% in Group 3.

Conclusion: In case of infiltration dominated by right middle or upper lobe involvement with a consolidation pattern, there is a higher risk of future intensive care need. Also, the need for intensive care increases as the number of affected lobes and percentage of affected parenchymal involvement increase.

Figure 1

Diagram shows the total number of patients and the mean duration of hospitalization by groups.

Figure 2. a–d

Demonstration of the normal evolution of the disease during a one-month course in a 46-year-old immunocompetent patient by volume-rendered 3D reconstruction in CT images (RadiAnt DICOM Viewer 5.5.1; Medixant). Chest CT image (a) at initial acquisition shows peripheral and central lesions affecting both lower and upper lobes. Control CT image (b) 5 days later shows diffuse infiltration affecting all lobes, especially on the left. CT image (c) 13 days after admission shows bilateral diffuse lung involvement with sparing of apical segments (white lung). CT image (d) at one-month follow-up shows interval marked regression of parenchymal findings.

Figure 3. a–f

CT imaging features of 3 male cases in the same age range (80–90 years old) who were treated as an outpatient (a, b), inpatient (c, d), and in the intensive care unit (e, f). GGOs are limited to subpleural areas in the lower lobe bases in Group 1 case, GGOs are affecting all lobes showing peripheral dominance in Group 2 case. Group 3 case shows diffuse GGOs infiltration up to both upper lobe apicals dominated by crazy-paving pattern. Note that both lower lobes are infiltrated by consolidations accompannied by pleural effusion. As involvement in form of widespread crazy-paving pattern ± consolidation, and/or affected lung parenchyma areas increase towards the upper lobes, a worse prognosis may be anticipated.

Figure 4. a–f

Coronal and axial CT images of 3 male patients of the same age (40-year-old), who were treated as outpatient (a, b), inpatient (c, d) and in the intensive care unit (e, f). They have similar diameters and infiltration patterns in the form of consolidation and ground-glass opacities in the right upper and middle lobe, distributed centrally and peripherally in the chest CT images. Estimating the prognosis with only CT imaging features may be misleading.