dcyphr | Early Clinical and CT Manifestations of Coronavirus Disease 2019 (COVID-19) Pneumonia


The researchers aimed to study early clinical and CT developments of COVID-19 pneumonia. These signs can provide clues for early diagnosis, prevention, and treatment.


The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the coronavirus disease (COVID-19). The virus has an envelope and granules. It originated from Wuhan, Hubei, China. Symptoms are acute, onset, and severe. The disease is very infectious. The virus is spread through respiratory droplets, contact, and fecal-oral route. The World Health Organization (WHO) has declared COVID-19 a global public health emergency. To diagnose this disease, doctors use epidemiological factors, clinical signs, CT findings, and nucleic acid detection of SARS-CoV-2. There is a recent change in diagnosis. If a patient has a combination of clinical signs and CT findings of pneumonia, they can be diagnosed as a confirmed case. 


The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid test using reverse transcription polymerase chain reaction (RT-PCR) confirmed COVID-19 pneumonia in patients. Doctors looked at symptoms, lab results, and CT scans.


This study included 108 patients with mild COVID-19 pneumonia. 1-3 days were allowed between onset of symptoms and CT examination. 87 percent of patients had a fever. Table 1 shows the different clinical symptoms. Table 2 shows the laboratory findings. All patients had a normal or decreased white blood cell count. 60 percent of patients had decreased lymphocyte count, and 40 percent of patients had normal levels. 99 percent of patients had increased high-sensitivity C-reactive protein levels. Table 3 shows CT findings. 65 percent of patients had multiple affected lung lobes. In patients where multiple lobes were affected, 97 percent of lesions were in the peripheral zone of the lung. If a single lobe was affected, 79 percent of cases involved the right lower lobe. Patchy ground-glass opacification (GGO)(86 percent) and GGO (80 percent) with consolidation are the most common CT features (Figures 1 and 2). Vascular thickening was seen in 80 percent of patients (Figure 3 and 4). The crazy paving pattern was seen in 40 percent of patients (Figure 4). 48 percent of patients had the air bronchogram sign (Figures 3 and 5), and 64 percent of patients have the halo sign (Figures 2 and 5). 63 percent of lesions were larger than 1 cm. No one had lymph node enlargement, pleural effusion, or pleural thickening.


Early detection and immediate treatment of COVID-19 is essential to stopping the spread. As of February 13, 2020, there are more than 60,000 cases in China. The SARS-CoV-2 nucleic acid detection is the reference standard. But, there is a high false-negative due to errors in nasopharyngeal swabbing. Multiple samples are often needed. Many patients delay treatment, contributing to spread. High-resolution CT that can detect millimeter-size lesions are important for early diagnosis of COVID-19 pneumonia. COVID-19 pneumonia is common in adults (mean age, 45), but rare in children and infants.  The right lower lobe may be most commonly affected due to its anatomy. The virus can easily infect the lobe because the bronchus is short and thick. COVID-19 may be similar to other coronaviruses, such as SARS-CoV and MERS-CoV, where an inflammatory cytokine storm causes pneumonia. There is diffuse alveolar damage. Exudation and edema in the alveoli are not obvious, possibly causing GGO, because the hyaline membrane is between the alveolar walls. Fibrosis and developments outside the lungs, such as lymph node enlargement are not seen in early lesions of COVID-19, but may be seen in later and more severe stages. One limitation was the lack of follow-up CT scans to investigate treatment efficacy and lack of lung biopsies to compare to CT data.


The early symptoms include low to midgrade fever, dry cough, and fatigue. Clinical manifestations include normal white blood cell (WBC) count, reduced lymphocyte count, and increased high-sensitivity C-reactive protein level. In the CT scans, doctors found patchy ground-glass opacification (GGO) either in one lobe or multiple lobes, mainly in the peripheral zone. Halo sign, vascular thickening, crazy paving pattern, or air bronchogram sign accompanies the GGO.