Correlation between chest computed tomography findings and pulmonary function test results in the post-recovery phase of COVID-19

ABSTRACT Objective The radiological and functional lung sequelae in COVID-19 survivors remain unclear. We compared the chest computed tomography findings of COVID-19 patients with normal and abnormal pulmonary function test results in the post-recovery phase. Methods The data of consecutive patients who underwent pulmonary function tests and chest computed tomography within 14 days after recovery from COVID-19 at two medical centers between May and October 2020 were collected retrospectively. Two thoracic radiologists who were blinded to the clinical information and pulmonary function test results classified the patients according to the computed tomography features, evidence of fibrotic-like changes, and semi-quantitative quantification of the extent of pulmonary abnormalities. The clinical characteristics and computed tomography findings of patients with normal pulmonary function test results were compared with those of patients with abnormal results. Results A total of 101 COVID-19 survivors, comprising 48 ambulatory and 53 hospitalized patients, were included at a median of 95 days from initial symptom onset. Computed tomography revealed fibrotic-like changes in 10.9% of patients. A reduction in the diffusion capacity of carbon monoxide was the most common lung function abnormality (19.8%). Abnormal diffusion capacity of carbon monoxide was associated with the presence and extension of lung opacities on chest computed tomography scans and fibrotic pulmonary abnormalities. The sensitivity, specificity, and accuracy of reduced diffusion capacity of carbon monoxide for detecting fibrotic-like pulmonary changes on chest computed tomography scans were 72.7%, 87.8%, and 86.1%, respectively. Conclusion Our study suggests that the presence of an abnormal diffusion capacity of carbon monoxide in the post-recovery phase of COVID-19 is associated with a greater risk of long-term parenchymal lung disease, as evidenced by the presence of fibrotic-like changes on chest computed tomography scans, such as traction bronchiectasis and architectural distortion.

Differential diagnoses of acute ground-glass opacity in chest computed tomography: pictorial essay / Diagnósticos diferenciais de opacidade em vidro fosco aguda na tomografia computadorizada de tórax: ensaio pictórico

ABSTRACT Ground-glass opacity is a very frequent and unspecified finding in chest computed tomography. Therefore, it admits a wide range of differential diagnoses in the acute context, from viral pneumonias such as influenza virus, coronavirus disease 2019 and cytomegalovirus and even non-infectious lesions, such as vaping, pulmonary infarction, alveolar hemorrhage and pulmonary edema. For this diagnostic differentiation, ground glass must be correlated with other findings in imaging tests, with laboratory tests and with the patients' clinical condition. In the context of a pandemic, it is extremely important to remember the other pathologies with similar findings to coronavirus disease 2019 in the imaging exams.

RESUMO A opacidade em vidro fosco é uma alteração muito frequente e pouco específica na tomografia computadorizada de tórax. Ela admite grande leque de diagnósticos diferenciais no contexto agudo, desde pneumonias virais, como as causadas pelo vírus influenza, pela doença do coronavírus 2019 e pelo citomegalovírus, até mesmo lesões de origem não infecciosa, como vaping , infarto pulmonar, hemorragia alveolar e edema pulmonar. Para essa diferenciação diagnóstica, deve-se correlacionar o vidro fosco com os demais achados nos exames de imagem, exames laboratoriais e quadro clínico do paciente. É de suma importância, no contexto de pandemia, recordar as demais patologias com os achados semelhantes aos da doença do coronavírus 2019 nos exames de imagem.

Anatomical variations and congenital anomalies of the ribs revisited by multidetector computed tomography / Variantes anatômicas e anomalias congênitas dos arcos costais revisitadas por meio da tomografia computadorizada de multidetectores

Abstract As they are asymptomatic or have a nonspecific, anatomical variations of the ribs are usually detected as incidental findings on imaging studies. They may be isolated changes or can be related to anomalies or clinical syndromes. Such variations are easily overlooked on conventional radiography and computed tomography if they are not actively investigated, mainly because most indications for a chest X-ray studies aim to evaluate the lung parenchyma and mediastinal structures. The objective of this pictorial essay was to use multislice computed tomography images to illustrate the imaging aspects of the main anatomical variations and congenital anomalies of the ribs.

Resumo As variantes anatômicas dos arcos costais são, geralmente, achados incidentais nos exames de imagem, em razão do seu comportamento assintomático ou quadro inespecífico, podendo constituir alterações isoladas ou relacionadas a anomalias e síndromes clínicas. Essas alterações são facilmente negligenciadas na radiografia convencional e na tomografia computadorizada se não forem investigadas ativamente, principalmente quando a maioria das indicações do estudo radiológico do tórax tem como objetivo a avaliação do parênquima pulmonar e das estruturas mediastinais. O objetivo deste artigo é demonstrar, por meio da tomografia computadorizada multidetectores, os aspectos de imagem das principais variantes anatômicas e anomalias congênitas dos arcos costais.

COVID-19 findings identified in chest computed tomography: a pictorial essay / Achados da COVID-19 identificados na tomografia computadorizada de tórax: ensaio pictórico

ABSTRACT The disease caused by the new coronavirus, or COVID-19, has been recently described and became a health issue worldwide. Its diagnosis of certainty is given by polymerase chain reaction. High-resolution computed tomography, however, is useful in the current context of pandemic, especially for the most severe cases, in assessing disease extent, possible differential diagnoses and searching complications. In patients with suspected clinical symptoms and typical imaging findings, in which there is still no laboratory test result, or polymerase chain reaction is not available, the role of this test is still discussed. In addition, it is important to note that part of the patients present false-negative laboratory tests, especially in initial cases, which can delay isolation, favoring the spread of the disease. Thus, knowledge about the COVID-19 and its imaging manifestations is extremely relevant for all physicians involved in the patient care, clinicians or radiologists.

RESUMO A doença causada pelo novo coronavírus, ou COVID-19, foi descrita recentemente e tornou-se uma questão de saúde mundial. Seu diagnóstico de certeza é dado pela reação em cadeia da polimerase. A tomografia computadorizada de alta resolução, entretanto, mostra-se útil no contexto atual de pandemia, especialmente nos casos mais graves, na avaliação da extensão da doença, em possíveis diagnósticos diferenciais e na pesquisa de complicações. Em pacientes com quadro clínico suspeito e achados de imagem típicos, nos quais ainda não há resultado laboratorial ou a reação em cadeia da polimerase não se encontra disponível, ainda se discute o papel desse exame. Importante ressaltar que parte dos pacientes apresenta exames laboratoriais falsos-negativos, notadamente em casos iniciais, o que pode retardar medidas de isolamento, favorecendo a propagação da doença. Dessa forma, o conhecimento da COVID-19 e de suas manifestações nos exames de imagem é de extrema importância para os médicos envolvidos no atendimento, sejam clínicos ou radiologistas.

Angiotomografia computadorizada de coronárias com tomógrafo com 320 fileiras de detectores e utilizando o AIDR-3D: experiência inicial / Coronary computed tomography angiography with 320-row detector and using the AIDR-3D: initial experience

A angiotomografia computadorizada de coronárias (angioTC de coronárias) é um excelente método de imagem não invasivo para avaliar a doença arterial coronariana. Atualmente, a dose de radiação efetiva estimada da angioTC de coronárias pode ser reduzida em tomógrafos de última geração com múltiplos detectores, como o tomógrafo com 320 fileiras de detectores (320-CT), sem prejuízo na acurácia diagnóstica da angioTC de coronárias. Para reduzir ainda mais a dose de radiação, novos algoritmos de reconstrução iterativa foram recentemente introduzidos por vários fabricantes de tomógrafos, que atualmente são utilizados rotineiramente nesse exame. Neste trabalho, apresentamos nossa experiência inicial na angioTC de coronárias utilizando o 320-CT e o Adaptive Iterative Dose Reduction 3D (AIDR-3D). Apresentamos ainda as indicações mais comuns desse exame na rotina da instituição bem como os protocolos de aquisição da, angioTC de coronárias com as atualizações relacionadas a essa nova técnica para reduzir a dose de radiação. Concluímos que a dose de radiação da angioTC de coronárias pode ser reduzida seguindo o princípio as low as reasonable achievable (tão baixo quanto razoavelmente exequível), combinando a indicação de exame com técnicas bem documentadas para a diminuição da dose de radiação, como o uso de betabloqueadores e a redução do kV, com os mais recentes aplicativos de reconstrução iterativa para redução da dose de radiação, como o AIDR-3D.

Coronary computed tomography angiography (coronary CTA) is a powerful non-invasive imaging method to evaluate coronary artery disease. Nowadays, coronary CTA estimated effective radiation dose can be dramatically reduced using state-of-the-art scanners, such as 320-row detector CT (320-CT), without changing coronary CTA diagnostic accuracy. To optimize and further reduce the radiation dose, new iterative reconstruction algorithms were released recently by several CT manufacturers, and now they are used routinely in coronary CTA. This paper presents our first experience using coronary CTA with 320-CT and the Adaptive Iterative Dose Reduction 3D (AIDR-3D). In addition, we describe the current indications for coronary CTA in our practice as well as the acquisition standard protocols and protocols related to CT application for radiation dose reduction. In conclusion, coronary CTA radiation dose can be dramatically reduced following the "as low as reasonable achievable" principle by combination of exam indication and well-documented technics for radiation dose reduction, such as beta blockers, low-kV, and also the newest iterative dose reduction software as AIDR-3D.