More than six weeks to resolve from CT manifestations in COVID-19 patient: A case report

Background: Coronavirus Disease 2019 (COVID-19) outbroke in Wuhan and spread to the world recently. But there were little studies on how long it took to recover from treatment beginning and resolve from chest computed tomography (CT) imaging so far. Case presentation: A patient diagnosed with severe type of COVID-19 was reported in this study. He was the �rst patient recovered and discharged from our hospital located in Guangzhou city. Initial chest computed tomography (CT) images of him showed bilateral multiple lobular peripheral ground-glass opacities without consolidation. Features and changes of his chest CT images from admission to discharge and follow-up were demonstrated. It took more than six weeks for lesion resolution in CT manifestations although the symptoms improved for a period of time after proper treatment. Conclusions: Repeated chest CT imaging for a period of more than six weeks in patients of COVID-19 is necessary to ascertain the lesion resolution and completely recovery. The result could be supplementary data to COVID-19 and help health care providers manage the COVID-19 patients.


Background
Coronavirus Disease 2019 (COVID-19) outbroke in Wuhan and spread to the world recently.World Health Organization reported it on January 12, 2020 [1] and declared it as a global health emergency on January 30, 2020.The 2019 novel coronavirus (SARS-CoV-2) was identi ed by whole-genome sequencing method and described in early study by Zhu et al [2] .Huang et al [3] demonstrated clinical features of COVID-19 patients within groups of intensive care unit (ICU) care and no ICU care.After that, supplementary data of epidemiological and clinical characteristics was demonstrated by Chen et al [4] .But there were little studies on how long it took to recover from treatment beginning and resolve from chest computed tomography (CT) imaging so far.In this study, we reported a patient diagnosed with severe type of COVID-19 from admission to discharge and follow-up.Clinical characteristics, including chest CT manifestations, were demonstrated.

Case Presentation
A 37-year-old man presented a 4-day history of fever and cough before admission.The highest temperature was 38.3℃.He was isolated and treated in isolation unit, Department of Infectious Diseases of Third A liated Hospital of Sun Yat-sen University from January 22 nd , 2020 to February 7 th , 2020.He had exposure history to suspected patient who travelled back from Wuhan, China.He denied of exposure to the Huanan seafood market or wild animals.His wife was con rmed diagnosed with COVID-19 two days after his admission.He was a non-smoker without any comorbidity.
At admission, the patient's body temperature was 37.3°C, blood pressure was 131/65 mm Hg, pulse was 104 beats per minute, respiratory rate was 18 breaths per minute, and pulse oxygen saturation (SpO 2 ) is 98% while he was breathing ambient air.Auscultation of lungs showed no wet or dry rales.Arterial blood gas analysis indicated no abnormality with arterial partial pressure of oxygen (PaO2) of 94.1 mm Hg and Oxygenation Index (arterial partial pressure of oxygen to fraction of inspiration oxygen [PaO 2 /FiO 2 ]) of 448 mm Hg.
Other laboratory examinations showed normal blood cell count, normal level of biochemical tests (hepatic function, renal function, cardiac function and coagulation function), normal level of procalcitonin, C-reactive protein and erythrocyte sedimentation rate.Antigen tests for In uenza A, B and IgM tests for In uenza A, B, Parain uenza, Respiratory Syncytial Virus, Adenovirus, Mycoplasma Pneumoniae, Chlamydia Pneumoniae, Rickettsia Burneti, Legionella Pneumophila were all negative.Blood cultures for bacterium (aerobic and anaerobic) and fungus were negative.Detection of SARS-CoV-2 nucleic acid from his oropharyngeal swab was positive by Center for Disease Control and Prevention (CDC) of Guangzhou city.Unenhanced chest CT images showed bilateral multiple lobular peripheral ground-glass opacities (GGO) without consolidation (Figure 1A).Diagnosis with COVID-19 was con rmed.
After admission, the patient received antiviral therapy of oral arbidol, oral lopinavir and ritonavir, and interferon alfa-2b inhalation.Antibiotic agent of Moxi oxacin, human immunoglobulin injection and nasal cannula oxygen support were given to him.The symptoms did not improve until day 8 th after admission.He was diagnosed with severe type of COVID-19 as his arterial blood gas analysis indicated abnormality with PaO2 of 79.9 mm Hg and Oxygenation Index of 242 mm Hg on day 9 th after admission, according to diagnosis and treatment program in our country [5] .Repeated chest CT imaging were nished in the course to ascertain the change of manifestations, which demonstrated new GGO on day 3 rd (Figure 1B), progression on day 11 th (Figure 1C) and partial absorption of the lesion on day 14 th (Figure 1D) after admission.Two consecutive negative results of detection the SARS-CoV-2 nucleic acid from his oropharyngeal swabs by CDC on day 13 th and day 16 th after admission, with an interval of 72 hours, were obtained before he was discharged on day 17 th after admission (Table 1).The treatment mentioned above was given to him until he was discharged.After discharge, he did not receive any drug as he felt normal.1).Chest CT images showed that most of the lesions were resolved, with some remaining patchy opacities in bilateral lower lobes (Figure 1E).After that, serum SARS-CoV-2 IgM was negative and IgG was positive on March 18 th , 2020 (day 40 th after discharge) (Table 1).

Discussion And Conclusions
was similar to Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) which was globally spread from November 2002 to July 2003 [6] , and Middle East Respiratory Syndrome Coronavirus (MERS-CoV)which was rst reported in Saudi Arabia in 2012 [7] .COVID-19 ranged from mild type to life-threatening.Acute respiratory distress syndrome (ARDS) and/or multiple organ disfunction syndrome (MODS) were recorded [3,4] .This reminds us not to underestimate the severity of the disease.It is still unknown how long it takes COVID-19 patients from symptoms onset to recovery, or from admission to hospital, receiving proper treatment, to discharge from hospital.
Initial chest CT images of the patient in our case report demonstrated that GGO were found without speci city.Similar ndings were reported in two studies [8,9] .New GGO in right upper lobe, right lower lobe and left lower lobe were visible on day 3 rd after admission although he was receiving proper treatment.This nding is similar to the rst case of COVID-19 in the United States [10] , who took more than 11 days of treatment in hospital, with remaining cough unresolved, increasing left basilar opacity was visible on day 5 th and stable streaky opacities in the lung bases were visible on day 6 th after his admission.In our case report, the symptoms of the patient did not improve until day 8 th after admission.Only partial absorption without absolutely resolution of the opacities was visible on day 14 th after admission before he was discharged, although the symptoms improved for a period of time.He had remaining patchy opacities in bilateral lower lobes in chest CT images on day 26 th after his discharge.It seemed to take a long period of time for COVID-19 patients from treatment beginning to recovery, and for complete lesion absorption in chest CT imaging.
In Huang's study, tness for discharge was based on abatement of fever for at least 10 days, with improvement of chest radiographic evidence and viral clearance in respiratory samples from upper respiratory tract [3] .Normal body temperature maintaining for 3 days, obvious improvement of respiratory symptoms, absorption of in ammation in chest radiographic manifestation and two negative results of detecting SARS-CoV-2 nucleic acid from respiratory samples with an interval of more than 24 hours, are all recommended for patients discharging from hospital in diagnosis and treatment program in our country [5] .All the discharged patients are also recommended to take home quarantine and self-health monitoring for at least 14 days.
Our case report indicated that repeated chest CT imaging for a period of more than six weeks in COVID-19 patients is necessary to ascertain the lesion resolution and complete recovery.The result could be supplementary data to COVID-19 and help health care providers manage the COVID-19 patients.

Table 1
Detection of nucleic acid and antibody of SARS-CoV-2For further examinations in the follow-up, the patient came back to our hospital without any symptoms on March 4 th , 2020 (day 26 th after discharge).SARS-CoV-2 nucleic acid from his oropharyngeal swabs and serum SARS-CoV-2 IgM were negative, serum SARS-CoV-2 IgG was positive (Table