COVID-19 pneumonia: Relationship between initial chest X-rays and laboratory findings

To analyze the initial findings in chest X-rays of patients with RT-PCR positive for SARS-CoV-2, and to determine whether there is a relationship between the severity of these findings and the clinical and laboratory findings.

This retrospective study analyzed the relationship between initial chest X-rays and initial laboratory tests in symptomatic adults with nasopharyngeal RT-PCR results positive for SARS-CoV-2 seen at our center between February 29 and March 23, 2020. Among other radiologic findings, we analyzed ground-glass opacities, consolidations, linear opacities, and pleural effusion. We also used a scale of radiologic severity to assess the distribution and extent of these findings. Among initial laboratory findings, we analyzed leukocytes, lymphocytes, platelets, neutrophil-to-lymphocyte ratio, and C-reactive protein.

Of 761 symptomatic patients, 639 (84%) required hospitalization and 122 were discharged to their homes. The need for admission increased with increasing scores on the scale of radiologic severity. The extent of initial lung involvement was significantly associated with the laboratory parameters analyzed (P<.05 for platelets, P<.01 for lymphocytes, and P<.001 for the remaining parameters), as well as with the time from the onset of symptoms (P<.001).

It can be useful to use a scale of radiologic severity to classify chest X-ray findings in diagnosing patients with COVID-19, because the greater the radiologic severity, the greater the need for hospitalization and the greater the alteration in laboratory parameters.