HomeRadiology: Cardiothoracic ImagingVol. 2, No. 4 PreviousNext Images in Cardiothoracic ImagingFree AccessVascular ImagingThe Target Sign and Its Variant in COVID-19 PneumoniaLucas de Pádua Gomes de Farias , Fernando Henrique Caixeta Souza, Gustavo Borges da Silva TelesLucas de Pádua Gomes de Farias , Fernando Henrique Caixeta Souza, Gustavo Borges da Silva TelesAuthor AffiliationsFrom UnitedHealth Group Brazil, Hospital Samaritano, R. Conselheiro Brotero 1486, Higienópolis, São Paulo, SP 01232-010, Brazil.Address correspondence to L.d.P.G.d.F. (e-mail: [email protected]).Lucas de Pádua Gomes de Farias Fernando Henrique Caixeta SouzaGustavo Borges da Silva TelesPublished Online:Aug 13 2020https://doi.org/10.1148/ryct.2020200435MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack Citations ShareShare onFacebookTwitterLinked In The target sign, identified at chest CT, has been recently described by Müller et al (1) as a nodular opacity in the center of a ring-like opacity in patients with pneumonia caused by the severe acute respiratory syndrome coronavirus 2. Pulmonary vascular alterations are significantly associated with coronavirus disease 2019 (COVID-19) (2,3), and lung autopsies showed distinctive vascular features characterized by endothelial injury with disrupted cell membranes (endothelialitis), widespread thrombosis with microangiopathy, and angiocentric inflammation (4). Thus, the central nodular opacity may reflect the perivascular inflammation or focal enlargement of the pulmonary artery (1). Furthermore, the ring-like opacities may be correlated with the underlying pathophysiologic mechanisms of the disease process as it organizes, indicating that the organizing pneumonia is one of the mechanisms of lung injury, but distinct from the reversed halo sign and the perilobular opacity (1). The variant of target sign here described is characterized by multiple concentric perivascular ring-like opacities. Further evaluation and pathologic studies are required to investigate the contribution of this sign in the diagnosis of COVID-19 pneumonia (Figs 1, 2).Figure 1: Schematic drawing, A, E, and chest CT images (B, axial, C, coronal, D, sagittal, and E, sagittal oblique) show the target sign characterized by nodular opacity in the center of a ring-like opacity. Some multiplanar reformatted planes, E, show the central nodule as a pulmonary arteriole (arrowhead) with perivascular ground-glass tubular opacity, as illustrated in F.Figure 1:Download as PowerPointOpen in Image Viewer Figure 2: Schematic drawing, A, and chest CT images (B-D, axial oblique, E, coronal, and F, sagittal) show the variant target sign characterized by multiple concentric ring-like opacities with a central nodular peribronchovascular opacity.Figure 2:Download as PowerPointOpen in Image Viewer Disclosures of Conflicts of Interest: L.d.P.G.d.F. disclosed no relevant relationships. F.C.S. disclosed no relevant relationships. G.T. disclosed no relevant relationships.Keywords: Adults and Pediatrics, CT, Infection, Lung, Thorax, Vascular Authors declared no funding for this work.
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