Clinical and CT findings of COVID-19: differences among three age groups

Abstract

Background: The novel coronavirus pneumonia (coronavirus disease 2019, COVID-19) has spread around the world. We aimed to recapitulate the clinical and CT imaging features of COVID-19 and their differences in three age groups.

Methods: The clinical and CT data of patients with COVID-19 (n = 307) that had been divided into three groups (Group 1: < 40 years old; Group 2: 40 ≤ age < 60 years old; Group 3: ≥ 60 years old) according to age were analyzed retrospectively.

Results: Of all patients, 114 (37.1%) had histories of epidemiological exposure, 48 (15.6%) were severe/critical cases, 31 had hypertension (10.1%), 15 had diabetes mellitus (4.9%), 3 had chronic obstructive pulmonary disease (COPD, 1%). Among the three groups, severe/critical type, hypertension and diabetes occurred more commonly in the elderly group compared with Group 1&2 (P < 0.05, respectively). Cough and chest tightness/pain were more commonly appeared in Group 2&3 compared with Group 1 (P < 0.05, respectively). Compared with Group 1 and 2, there were more abnormal laboratory examination indexes (including CRP increase, abnormal percentage of lymphocytes, neutrophils and monocytes) in Group 3 (P < 0.05, respectively). CT images revealed that more lobes were affected and more subpleural lesions were involved in the elderly group, besides, crazy paving sign, bronchodilatation and pleural thickening were more commonly seen in the elderly group, with significant difference between Group 1&2, Group 2&3 (P < 0.05, respectively).

Conclusions: COVID-19 presented representative clinical manifestations, laboratory examinations and CT findings, but three age groups possessed their own specific characteristics. Grasping the clinical and CT features stratified by age will be helpful for early definite diagnosis of COVID-19.

Keywords: Age; COVID-19; Pulmonary infection; X-ray computed tomography.

Fig. 1

Flow diagram of enrolled patients

Fig. 2

Stacked bars (green) show the age and number distribution of the heavy/critical type of COVID-19. The curve (red) represents the number distribution trend of the heavy/critical type according to the levels of age

Fig. 3

Atypical case a: Mild type patient. CT showed a small pGGO in the right middle lobe (arrow), and no abnormality in the remaining lobes. Atypical case b: Mild type patient. Only a small pGGO was detected in the left upper lobe with hale sign (arrow). Typical case c: Moderate type patient. CT showed multiple GGOs in the bilateral lobes with vascular dilatation and halo sign (arrow). Typical case d: Heavy type patient. CT showed diffused GGOs in the bilateral lobes

Fig. 4

Typical pGGO case a: Moderate type patient. CT showed multiple pGGOs in the bilateral lung lobes with halo sign (arrow). Some of the lesions were located under the pleura. Typical mGGO case b: Moderate type patient. CT showed a subpleural mGGO within a solitary nodule (arrow)

Fig. 5

Typical CT signs. Halo sign a: Moderate type patient. CT showed a pGGO with halo sign in the left low lobe (arrow). reversed halo sign b: Moderate type patient. CT showed a mGGO with reversed halo sign (arrow). Crazy paving sign c: Moderate type patient. CT showed two pGGOs with crazy paving sign in the left low lobe (arrow). Cavity sign d: Moderate type patient. CT showed a pGGO with a small cavity (arrow)

Fig. 6

Stacked bars show the distribution of number of lesions on CT images for three age groups. Patients were grouped by age: (Group 1: < 40 years old; n = 104), (Group 2:40 ≤ age < 60 years old; n = 137), (Group 3: ≥ 60 years old; n = 66)