Imaging findings in COVID-19 pneumonia

Abstract

The coronavirus disease , caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in Wuhan city and was declared a pandemic in March 2020. Although the virus is not restricted to the lung parenchyma, the use of chest imaging in COVID-19 can be especially useful for patients with moderate to severe symptoms or comorbidities. This article aimed to demonstrate the chest imaging findings of COVID-19 on different modalities: chest radiography, computed tomography, and ultrasonography. In addition, it intended to review recommendations on imaging assessment of COVID-19 and to discuss the use of a structured chest computed tomography report. Chest radiography, despite being a low-cost and easily available method, has low sensitivity for screening patients. It can be useful in monitoring hospitalized patients, especially for the evaluation of complications such as pneumothorax and pleural effusion. Chest computed tomography, despite being highly sensitive, has a low specificity, and hence cannot replace the reference diagnostic test (reverse transcription polymerase chain reaction). To facilitate the confection and reduce the variability of radiological reports, some standardizations with structured reports have been proposed. Among the available classifications, it is possible to divide the radiological findings into typical, indeterminate, atypical, and negative findings. The structured report can also contain an estimate of the extent of lung involvement (e.g., more or less than 50% of the lung parenchyma). Pulmonary ultrasonography can also be an auxiliary method, especially for monitoring hospitalized patients in intensive care units, where transfer to a tomography scanner is difficult.

Reply to: Temporal evolution of tomographic findings of pulmonary infection in COVID-19

“…Besides greater incidence of venous and arterial thromboses (5) described in these patients, we have also observed coinfection and superinfection, which are sometimes dramatic cases, generating imaging patterns that challenge the most classic aspects, as illustrated by us, (3) and also by other Brazilian authors. (4) Yet, we believe it is worth mentioning the higher incidence of barotrauma in these patients, (6) another factor that may contribute to pulmonary damage. All these complications can also influence in the progressive imaging changes of COVID-19 and have the potential to leave residual findings in the parenchyma.…”

“…On the other hand, we have seen ground-glass opacities persisting for a long time in some patients. Although the progressive imaging behavior in COVID-19 is relatively predictable, (3,4) there are still cases that challenge this pattern.…”

“…Também temos observado casos de lesões extensas, por vezes com características similares às relatadas pelos autores, que apresentam melhora substancial dos achados durante a evolução. Por outro lado, vemos alguns pacientes que persistem com achados de vidro fosco por bastante tempo, de forma que, muito embora o comportamento evolutivo por imagem da COVID-19 seja relativamente previsível, ( 3 , 4 ) ainda há casos que desafiam esse padrão.…”

“…Além da maior incidência de tromboses venosas e arteriais ( 5 ) que vem sendo descrita nesses pacientes, também temos observado quadros de coinfecção e superinfecção, algumas vezes de aspecto dramático, gerando padrões de imagem que desafiam os aspectos mais clássicos, como ilustrados não somente por nós, ( 3 ) mas também por outros autores na realidade nacional. ( 4 ) Não obstante, acreditamos que mereça também destaque a maior incidência de barotrauma nesses pacientes, ( 6 ) outro fator que pode contribuir para o dano pulmonar. Todas essas complicações também podem influenciar na evolução por imagem das alterações de base da COVID-19 e têm potencial para deixar achados residuais no parênquima.…”

Rational use of chest ultrasound to confront COVID-19

“…The first reports of pulmonary presentations, analyzed by computed tomography (CT) in this disease, show peripheral ground-glass opacities, predominating in the posterior segments of the lung, centrilobular consolidation, and mosaic paving pattern, which can be examined with ultrasound, due to the peripheral location of the lesions ( 9 , 10 ) .…”