key: cord-0834720-9m2i7xea
authors: Shaghaghi, Shiva; Daskareh, Mahyar; Irannejad, Mona; Shaghaghi, Mohammadreza; Kamel, Ihab R.
title: Target-shaped combined halo and reversed-halo sign, an atypical chest CT finding in COVID-19
date: 2020-07-02
journal: Clin Imaging
DOI: 10.1016/j.clinimag.2020.06.038
sha: 7c5e29aaa0240a518633820b85fe390608ac3f7c
doc_id: 834720
cord_uid: 9m2i7xea

Typical chest CT findings in COVID-19 have been described as bilateral peripheral ground glass opacities, with or without consolidation. Halo sign and reversed halo sign have been reported as atypical imaging findings in this disease. However, to the best of our knowledge, combined presence of these signs has never been reported before. Herein, we present a COVID-19 patient with numerous atypical target-shaped, combined halo and reversed halo pulmonary lesions, in the absence of any other underlying disease.

The first clinical case of coronavirus disease 2019 (COVID-19) was reported in Wuhan city, China.

To date (May 14, 2020), 4,248,389 patients have been infected, with 292,046 deaths reported worldwide [1] .

Clinical symptoms of COVID-19 are non-specific and include fever, cough, myalgia, or fatigue. Less common symptoms are diarrhea, nausea, headache, sputum production, and hemoptysis.

Approximately, half of the patients experience dyspnea during disease progression [2] . The predominant chest CT findings in COVID-19 have been described as bilateral and peripheral ground glass opacities, with or without consolidation. Lymphadenopathy, pleural effusion, and lung J o u r n a l P r e -p r o o f pleural effusion was noted in the right hemithorax. No lymphadenopathy, pericardial effusion, collapse, or cavitary changes were found.

The patient was started on multidrug treatment with hydroxychloroquine (400 mg/OD), oseltamivir (75 mg/BD), ribavirin (400 mg/BD), levofloxacin (500 mg/OD), and naproxen (500 mg/BD). He responded well to treatment. His fever resolved within 48 hours and his respiratory symptoms subsided in 5 days of hospitalization. He did not require endotracheal intubation or ICU admission.

The patient was discharged after one week with stable vital signs, and his SpO2 was 95%.

Four weeks after disease onset, a follow-up CT scan ( Figure 2 ) showed complete clearance of consolidations. Diffuse round pure ground glass opacities were seen in both lungs without intra-or inter-lobular septal thickening. Scar formation, cavitation, atelectasis, or lymphadenopathy were absent.

In this study, we reported a COVID-19 patient with an unusual chest CT finding of combined halo and reverse halo signs coexisting on the same study, who recovered rapidly after multidrug treatment.

Alveolar edema and hemorrhage may create the halo sign, while the reversed-halo sign may be formed by the organization and resolution of alveolar exudates [9] . Although these findings are not specific, they are highly suggestive for early stages of opportunistic invasive fungal infections (e.g. aspergillosis, mucormycosis) in immunocompromised patients. They might be seen in immunocompetent individuals in other conditions such as non-fungal endemic infections, cryptogenic organizing pneumonia, vasculitis, and neoplastic and inflammatory diseases [8] . The Reversed Halo sign in invasive fungal infections appears as one or more large lesions; while in endemic infections (e.g. tuberculosis), lesions have a bilateral and asymmetric appearance with J o u r n a l P r e -p r o o f ground glass opacities, centrilobular nodules, or consolidations [10] . The multilobular, peripheral target-shaped findings in our COVID-19 patient were unlikely due to fungal co-infection, given lack of history of immunodeficiency, short disease course, and the resolution of consolidations without any antifungal treatment.

Bernheim et al. reported that the frequency of uncommon chest CT findings, including the reversed halo sign, increases in the later stages of COVID-19 progression [11] . There are no adequate data to explain the pathophysiology of the combined lesions in our patient. The coexistence of both halo and reversed halo signs could be an atypical presentation in COVID-19. To the best of our knowledge, this imaging feature has never been described before.

This case report provides information for future secondary articles and systematic reviews. We advocate reporting unusual presentations of COVID-19 patients. Future studies on this data should be warranted better understand the pathophysiology and different characteristics of this newly emerged disease.

A video of axial CT images is available as an online appendix. 

World Health Organization. Coronavirus disease (COVID-19) situation report

Clinical features of patients infected with 2019 novel coronavirus in Wuhan

CT imaging features of 2019 novel coronavirus (2019-nCoV)

Novel Coronavirus (2019-nCoV) Pneumonia

Coronavirus Disease 2019 (COVID-19): A Systematic Review of Imaging Findings in 919 Patients

Radiological manifestations from 101 patients with 2019 Novel Coronavirus Disease (COVID-19) in Hamadan, West of Iran: Typical and atypical findings

CT characteristics of patients infected with 2019 novel coronavirus: association with clinical type

The diagnostic value of halo and reversed halo signs for invasive mold infections in compromised hosts

Progress and prospect on imaging diagnosis of COVID-19

Reversed halo sign: a systematic review

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