Abstract:The epidemic of 2019 novel coronavirus, later named as coronavirus disease (COVID-19), began in Wuhan, China in December 2019 and has spread rapidly worldwide. Early diagnosis is crucial for the management of the patients with COVID-19, but the gold standard diagnostic test for this infection, the reverse transcriptase polymerase chain reaction, has a low sensitivity and an increased turnaround time. In this scenario, chest computed tomography (CT) could play a key role for an early diagnosis of COVID-19 pneum… Show more
“…The halo sign represents area of consolidation/pulmonary nodule/mass surrounded by ground-glass opacity [ 34 – 36 ] as shown in the Fig. 6 .…”
Section: Discussionmentioning
confidence: 99%
“…In current limited research, only few cases reports on the halo sign has been made in COVID-19 [ 11 , 37 , 38 ]. Based on the pathological findings as seen in some recent studies, extensive thrombotic damage of the pulmonary microcirculation can explain the “halo sign” of consolidations [ 34 ]. Fig.…”
Background
The typical CT manifestations of COVID-19 pneumonia include ground-glass opacity (GGO) with or without consolidation and superimposed interlobular septal thickening. These are often rounded in morphology and frequently bilateral, multilobar, posterior, peripheral, and basilar in distribution. The various atypical CT features of COVID-19 are seldom described in the literature. The study aims to enumerate the atypical pulmonary CT features in patients with COVID-19 pneumonia in correlation with the disease severity.
Results
A total of 298 confirmed cases of COVID-19 pneumonia with positive reverse transcription polymerase chain reaction (RT-PCR) who underwent chest CT scans were retrospectively evaluated. The cohort included 234 (78.5%) men and 64 (21.5%) women and the mean age was 53.48 ± 15.74 years. The most common presenting symptoms were fever [n = 197 (66.1%)] and cough [n = 139 (46.6%)]. Out of 298 cases of COVID-19 pneumonia, 218 cases (73.1%) showed typical CT features while 63 cases (21.1%) showed atypical CT features with concurrent classical findings and the remaining 17 cases (5.8%) were normal. Among the atypical CT features, the most common was pulmonary cysts [n = 27 (9%)]. The other features in the order of frequency included pleural effusion [n = 17 (5.7%)], nodules [n = 13 (4.3%)], bull’s eye/target sign[n = 4 (1.3%)], cavitation [n = 3 (1.0%)], spontaneous pneumothorax [n = 2 (0.6%)], hilar lymphadenopathy [n = 2 (0.6%)], spontaneous pneumo-mediastinum with subcutaneous emphysema [n = 1 (0.3%)], Halo sign [n = 1 (0.3%)], empyema [n = 1 (0.3%)] and necrotizing pneumonia with abscess [n = 1 (0.3%)].
Conclusion
CT imaging features of COVID-19 pneumonia while in a vast majority of cases is classical, atypical diverse patterns are also encountered. A comprehensive knowledge of various atypical presentations on imaging plays an important role in the early diagnosis and management of COVID-19.
“…The halo sign represents area of consolidation/pulmonary nodule/mass surrounded by ground-glass opacity [ 34 – 36 ] as shown in the Fig. 6 .…”
Section: Discussionmentioning
confidence: 99%
“…In current limited research, only few cases reports on the halo sign has been made in COVID-19 [ 11 , 37 , 38 ]. Based on the pathological findings as seen in some recent studies, extensive thrombotic damage of the pulmonary microcirculation can explain the “halo sign” of consolidations [ 34 ]. Fig.…”
Background
The typical CT manifestations of COVID-19 pneumonia include ground-glass opacity (GGO) with or without consolidation and superimposed interlobular septal thickening. These are often rounded in morphology and frequently bilateral, multilobar, posterior, peripheral, and basilar in distribution. The various atypical CT features of COVID-19 are seldom described in the literature. The study aims to enumerate the atypical pulmonary CT features in patients with COVID-19 pneumonia in correlation with the disease severity.
Results
A total of 298 confirmed cases of COVID-19 pneumonia with positive reverse transcription polymerase chain reaction (RT-PCR) who underwent chest CT scans were retrospectively evaluated. The cohort included 234 (78.5%) men and 64 (21.5%) women and the mean age was 53.48 ± 15.74 years. The most common presenting symptoms were fever [n = 197 (66.1%)] and cough [n = 139 (46.6%)]. Out of 298 cases of COVID-19 pneumonia, 218 cases (73.1%) showed typical CT features while 63 cases (21.1%) showed atypical CT features with concurrent classical findings and the remaining 17 cases (5.8%) were normal. Among the atypical CT features, the most common was pulmonary cysts [n = 27 (9%)]. The other features in the order of frequency included pleural effusion [n = 17 (5.7%)], nodules [n = 13 (4.3%)], bull’s eye/target sign[n = 4 (1.3%)], cavitation [n = 3 (1.0%)], spontaneous pneumothorax [n = 2 (0.6%)], hilar lymphadenopathy [n = 2 (0.6%)], spontaneous pneumo-mediastinum with subcutaneous emphysema [n = 1 (0.3%)], Halo sign [n = 1 (0.3%)], empyema [n = 1 (0.3%)] and necrotizing pneumonia with abscess [n = 1 (0.3%)].
Conclusion
CT imaging features of COVID-19 pneumonia while in a vast majority of cases is classical, atypical diverse patterns are also encountered. A comprehensive knowledge of various atypical presentations on imaging plays an important role in the early diagnosis and management of COVID-19.
“…McLaren et al described the bullseye sign, a variant of the reverse halo sign, as an atypical manifestation of COVID-19 pneumonia. Similarly, Poerio et al 2 described a combination of multiple and bilateral halo sign, reverse halo sign and double halo sign as main CT findings in a 55 year-old woman with COVID-19. Both authors explained these atypical findings as manifestations of organizing pneumonia (reverse halo sign) and extensive thrombotic damage of pulmonary microcirculation (halo sign and double halo sign).…”
Highlights
Radiologists should know the atypical CT findings of COVID-19 pneumonia as well as the typical ones
A single focal halo-sign lesion has never been described before as manifestation of COVID-19 pneumonia
CT halo-sign could represent a consequence of thrombotic damage of pulmonary microcirculation
In the setting of asymptomatic patients, unilateral single halo-sign should alert to the possibility of COVID-19 pneumonia
“…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).…”
Section: Double Halo Sign Target Sign and Bull's-eye Signmentioning
The term "sign" has been used to describe various phenomena observed in patients with coronavirus disease 2019 (COVID-19). Discrepancies in the use of this term have been identified when it is used in context with COVID-19. The goals of this review are to provide an overview, describe signs, and clarify misconceptions regarding the use of these terms in COVID-19 patients. PubMed and Medline databases were searched using individual and Medical Subject Headings (MeSH) terms, including coronavirus, COVID-19, and sign, in human studies within the English literature published from inception to December 31, 2020. Studies where the word "sign" was used in a context different from that for COVID-19 (e.g., sentinel sign) were excluded. Three hundred fifty-seven studies were potentially identified and after applying the exclusion criteria and further adjudication, 92 studies constituted the final data set. The majority of signs found in the COVID-19 literature have been applied and aptly described primarily in radiologic diseases of the chest. The term "sign," in other situations, is often misappropriated as it actually represents a physical finding rather than a sign. A total of 27 radiologic signs have been identified on chest computed tomography (CT) or high-resolution CT (HRCT), and 18 cutaneous signs (or findings) have been observed during the physical examination in COVID-19. Signs lack sufficient sensitivity or specificity by themselves; however, in the appropriate clinical setting, they should raise clinical suspicion for this infectious disease.
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