Chest CT target sign in a couple with COVID-19 pneumonia

Abstract

We describe a target sign on chest CT characterized by a combination of peripheral ring-like opacity and a central nodular ground-glass opacity surrounding a vessel in a couple with COVID-19 pneumonia confirmed by real-time reverse transcriptase fluorescence polymerase chain reaction sputum analysis.

New CT finding (the target sign) in three patients with COVID-19 pneumonia

“…The finding of perilobular opacity associated with central nodular opacity in the secondary pulmonary lobule on chest CT scans of patients with COVID-19 was first reported in a study published in June of 2020 9 and was designated the target sign. According to the authors of the study, 9 a perilobular pattern and the reversed halo sign are indicative of organizing pneumonia in patients with COVID-19; also according to the authors, in COVID-19 patients presenting with the target sign, the peripheral opacities are suggestive of organizing pneumonia, whereas the central nodular opacity is suggestive of vascular and perivascular inflammation or focal enlargement of the pulmonary artery. We suggest the possibility of organizing pneumonia involving the periphery and the center of the secondary pulmonary lobule, given that organizing pneumonia can present with peribronchovascular involvement.…”

Clarifying Terminology of Signs in COVID-19

“…Poerio et al (20) described a double halo sign with another rim of thicker ground glass opacity around the outer or peripheral thinner rim of consolidation. The target sign is a central nodular ground glass opacity and peripheral ring opacity resembling a "shooting star" (21). The bull's eye appearance or sign is similar to or a variant of the reverse halo sign that represents a central or centrilobular ground glass nodule surrounded by a peripheral or perilobular inner air ring and outer consolidation or ground glass opacity that is distributed peripherally (22).…”

Is the CT target sign specific to COVID-19 pneumonia?

“…In a series of nearly simultaneous studies, 2 - 5 the target sign has been described as a new CT finding in patients with COVID-19, consisting of central nodular opacity surrounded by a dense peripheral rim. The sign has variously been termed the target sign, 2 , 4 the “double halo” sign, 3 and the “bullseye” sign.…”

“…In a series of nearly simultaneous studies, 2 - 5 the target sign has been described as a new CT finding in patients with COVID-19, consisting of central nodular opacity surrounded by a dense peripheral rim. The sign has variously been termed the target sign, 2 , 4 the “double halo” sign, 3 and the “bullseye” sign. 5 However, the target sign appears to be the most appropriate and widely accepted term to describe it 2 , 4 , 6 because of its peculiar appearance, similar to that of a shooting target.…”

“…The sign has variously been termed the target sign, 2 , 4 the “double halo” sign, 3 and the “bullseye” sign. 5 However, the target sign appears to be the most appropriate and widely accepted term to describe it 2 , 4 , 6 because of its peculiar appearance, similar to that of a shooting target.…”