Differential diagnoses of acute ground-glass opacity in chest computed tomography: pictorial essay.

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.

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.

COVID-19 findings identified in chest computed tomography: a pictorial essay.

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.

Presentation of pulmonary infection on CT in COVID-19: initial experience in Brazil.

The disease caused by the new coronavirus (SARS-CoV-2), designated COVID-19, emerged in late 2019 in China, in the city of Wuhan (Hubei province), and showed exponential growth in that country. It subsequently spread to all continents, and infection with SARS-CoV-2 is now classified as a pandemic. Given the magnitude achieved, scientific interest in COVID-19 has also grown in the international literature, including its manifestations on imaging studies, particularly on CT. To date, no case series have been published in Brazil. Therefore, our objective was to describe the CT findings in an initial series of 12 patients.

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.

Coronary computed tomography angiography with 320-row detector and using the AIDR-3D: initial experience.

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.

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.

Achados de imagem da revascularização do miocárdio pela tomografia computadorizada por múltiplos detectores: onde estão os enxertos? Ensaio iconográfico / Imaging findings of myocardial revascularization at multidetector computed tomography: where are the bypass grafts? An iconographic essay

A angiotomografia por multidetectores de coronárias constitui um método preciso para avaliação dos enxertos venosos e arteriais pós-revascularização coronariana e vem substituindo em parte o cateterismo, o qual é um método invasivo e de maior custo. Este ensaio iconográfico tem como objetivo a demonstração anatômica dos enxertos mais comumente utilizados, como diferenciar enxertos venosos e arteriais e como localizá-los. Os exames foram realizados em aparelhos de tomografia computadorizada multislice de 64 fileiras de detectores, com apneia, frequência cardíaca controlada e protocolos adequados com posterior reconstruções MPR, MIP e 3D, de acordo com o eletrocardiograma. A localização dos enxertos e anastomoses em tomografias computadorizadas direcionadas para as artérias coronárias e para o tórax pode dificultar a análise do exame pelo radiologista não familiarizado, sendo que o conhecimento das técnicas cirúrgicas utilizadas e dos possíveis trajetos das pontes de safena e enxertos arteriais ajuda na análise de ambos os exames, evitando também erros diagnósticos.

Multidetector coronary computed tomography angiography is a precise method for evaluating post-coronary revascularization arterial and venous bypass grafts, and is somehow superseding coronary catheterization that is an invasive and more expensive technique. The present iconographic essay is aimed at anatomically demonstrating the bypass grafts most frequently utilized, how to differentiate between arterial and venous grafts and how to find them. The studies were performed in 64-row multidetector computed tomography equipment, with breath hold, controlled heart rate and appropriate protocols with later MPR, MIP and 3D reconstructions according to electrocardiogram. The localization of the bypass grafts and anastomoses at computed tomography studies focused on chest and coronary arteries may represent a difficulty in the images analysis by the radiologist who is not familiar with the matter, so the knowledge of the surgical techniques adopted and possible courses of the saphenous bypass grafts and arterial grafts can aid in the analysis of both studies, avoiding diagnostic errors.

Sinais tomográficos de tromboembolismo pulmonar crônico / Tomographic signs of chronic pulmonary emboli

O objetivo deste estudo é abordar os principais sinais tomográficos de tromboembolismo pulmonar crônico, que apesar ser entidade rara é considerada condição grave e de mau prognóstico, devendo ser prontamente diagnosticada, para permitir tratamento precoce e evitar um desfecho dramático, com evolução para hipertensão pulmonar. Serão apresentados, por meio de exames de imagem, os principais achados tomográficos diretos e indiretos relacionados à embolia pulmonar crônica. Os sinais de tromboembolismo pulmonar crônico são divididos em diretos e indiretos. Sinais diretos:obstrução luminal completa, falhas de enchimento não obstrutivas (irregularidades intimais, bandas e afilamentos focais) e maiores coeficientes de atenuação dos trombos crônicos em relação aos agudos. Sinais indiretos: aumento do calibre da artéria pulmonar, proeminência da circulaçãoarterial brônquica, aumento da relação ventrículo direito/esquerdo, refluxo de contraste para a veia cava inferior, tortuosidade dos ramos arteriais pulmonares periféricos, dilatações vasculares pós-estenóticas e perfusão em mosaico do parênquima pulmonar.

The purpose of this study is to review the most important tomographic signs of chronic pulmonary emboli, to make possible a precocious and precise diagnosis, since this disease can haveserious complications such as pulmonary hypertension, and right heart failure. There will be presented by means of tomographic images the most important direct and indirect signs of chronicpulmonary emboli. As direct signs we can find complete or partial artery occlusion, with higher thrombus attenuation when compared with acute process. Poststenotic vessel dilatation, tortuous pulmonary arteries, enlargement of the main pulmonary artery, enlargement of bronchial arteries and mosaic pattern of lung attenuation are classified as indirect signs.