The arch bridge sign: a newly described CT feature of the coronavirus disease-19 (COVID-19) pneumonia

Abstract

Background: To investigate the distribution of CT features and also to introduce a novel described CT feature of coronavirus disease-19 (COVID-19) pneumonia. Methods: A series of radiologic signs in 11 COVID-19 patients were summarized and made morphometric analysis. Results: A special sign termed as "the arch bridge sign" owing to its morphological mimicking an arch bridge was firstly introduced. Statistical analyze showed that the subpleural area is the priority distribution location (14/14) and the sign inclined to perform in those patients in a relatively early stage (6/8) and with moderate clinical severity (8/8). Segment VI in lower lobe involved most (6/14). In this retrospective study, other characteristic radiologic signs of COVID-19 pneumonia were analyzed synchronously. A series of radiologic signs were identified in bilateral lungs with a bias towards segment VI, I + II and X. Segment VI had the largest number of each sign. Ground-glass opacities (GGOs), subpleural distribution pattern and vessels dilatation were the top three most common signs among them. Conclusions: The recognition of the arch bridge sign may benefit patient care by earlier definitive diagnosis of COVID-19 pneumonia. The lesions of COVID-19 pneumonia distributed mainly in the backlung segments, which characteristic may light new ideas in clinical treatment and nursing strategy.

Chest computed tomography analysis of lung sparing morphology: differentiation of COVID-19 pneumonia from influenza pneumonia and bacterial pneumonia using the arched bridge and vacuole signs

“…This study evaluated the incidences and diagnostic values of the arched bridge and vacuole signs among patients with COVID-19 pneumonia in a Hong Kong Chinese population. Since the initial description of Wu et al 20…”

“…We hypothesised that these two signs are common in patients with COVID-19 pneumonia and thus could be used to differentiate such pneumonia from other types of infection-related pneumonia. However, considering the limited prior evidence (solely from small retrospective studies [20][21][22][23][24] ) regarding the prevalence of the vacuole sign in COVID-19 pneumonia, and because the arched bridge sign has-to our knowledge-only been reported in a single previous publication, 20 additional assessments of these signs are needed. The utilities of the arched bridge and vacuole signs in COVID-19 pneumonia have not been directly assessed in prior reports, nor have they been compared between COVID-19 pneumonia and other types of infection-related pneumonia.…”

“…A report by Wu et al 20 highlighted the arched bridge sign, which may be a distinct CT feature of COVID-19 pneumonia. In their analysis of 11 patients with COVID-19 pneumonia, the sign was present in 72.7%.…”

“…In their analysis of 11 patients with COVID-19 pneumonia, the sign was present in 72.7%. 20 The arched bridge sign refers to a specific pattern of GGOs or consolidation, commonly in a subpleural location, which forms an arched contour with a smooth concave margin towards the pleural side. The arched margin outlines the spared parenchyma between the GGOs or consolidation and the pleural surface.…”

Clarifying Terminology of Signs in COVID-19

“…Air bronchogram (bronchi) sign (6,35) Air bubble (vacuolar) sign (31) Arch bridge sign (36) Cavity sign (37) Central vascular sign (38) Comb sign (38) Crazing paving pattern or sign or Paving stone sign (37,40) Feeding vessel sign (30) Ginkgo leaf sign (38) Grid-form sign (39) Gypsum sign (23,35) Large cable sign (28) Parallel pleural sign (40) Pomegranate sign (25) Rosa roxburghii (rose) sign (23,35) Sieve sign (35) Spider web sign (38) Tree-in bud sign (37) White lung (blizzard sign) (23, 35) Outline of the airway caused by opacities surrounding the airway die to fluid or inflammatory exudate.…”