|Year : 2020 | Volume
| Issue : 3 | Page : 118-123
Findings in chest radiographs of patients admitted with novel coronavirus infection at a tertiary care institution in India: A retrospective study
Amit Bajpai1, Sagar Arora1, Gaurav Shukla1, PI Hashim1, Somnath Pan1, Niharika Gupta1, Rajeev Sivasankar1, Sheila S Mathai2
1 Department of Radiodiagnosis and Imaging, INHS Asvini, Mumbai, Maharashtra, India
2 Commanding Officer, INHS Asvini, Mumbai, Maharashtra, India
|Date of Submission||18-Sep-2020|
|Date of Decision||06-Oct-2020|
|Date of Acceptance||10-Oct-2020|
|Date of Web Publication||16-Nov-2020|
Surg Cdr P I Hashim
Department of Radiodiagnosis and Imaging, INHS Asvini, Mumbai, Maharashtra
Source of Support: None, Conflict of Interest: None
Aim: In the ever-changing understanding of the ongoing COVID 19 pandemic, this study aims to present the spectrum of findings in chest radiographs conducted in serologically proven symptomatic patients of COVID 19 in a tertiary care hospital in Mumbai, India. Methods: The study was a retrospective analysis of 449 chest radiographs(CXRs) obtained from serologically proven symptomatic 312 COVID patients in a tertiary care institute at Mumbai, India. CXRs were conducted as per a hospital approved protocol. The x-rays were analysed by three radiologists for presence of consolidation, ground glass opacities, interstitial opacities and distribution of findings. Results: Out of the total CXRs reviewed, 50.7% were abnormal with 91.7% of them showing the commonest pattern of finding as consolidation. The majority of findings were seen (71.1%) in patients above 50 yrs of age. 84 cases (26.9%) had a serial radiograph follow up mandated by their clinical status. Of these, 75% were abnormal. There were 46 fatal cases, out of which 22 patients (47.82%) underwent CXRs and 10 (21.73%) were followed up. All of these radiographs (100%) showed abnormal findings. Conclusions: Chest radiographs conducted in this retrospective analysis of patients with symptomatic COVID-19 infections showed that a little more than half of the patients with the infection had abnormal findings. The commonest pattern of involvement was a patchy peripheral consolidation with no predilection for any particular side. However, there was a significant basal predominance (85.5%). The progression of findings was seen in 75% of the CXRs with good correlation between clinical & radiological severity. The study shows that CXRs have an important diagnostic and prognostic role in the management of patients with the COVID-19 infection.
Keywords: Chest radiographs, chest X-rays in coronavirus disease 2019, novel coronavirus pandemic
|How to cite this article:|
Bajpai A, Arora S, Shukla G, Hashim P I, Pan S, Gupta N, Sivasankar R, Mathai SS. Findings in chest radiographs of patients admitted with novel coronavirus infection at a tertiary care institution in India: A retrospective study. J Mar Med Soc 2020;22, Suppl S1:118-23
|How to cite this URL:|
Bajpai A, Arora S, Shukla G, Hashim P I, Pan S, Gupta N, Sivasankar R, Mathai SS. Findings in chest radiographs of patients admitted with novel coronavirus infection at a tertiary care institution in India: A retrospective study. J Mar Med Soc [serial online] 2020 [cited 2021 Jun 20];22, Suppl S1:118-23. Available from: https://www.marinemedicalsociety.in/text.asp?2020/22/3/118/300650
| Introduction|| |
The coronavirus disease 2019 (COVID 19) pandemic is a global problem which is still evolving in terms of understanding of pathogenesis, improving diagnostic modalities, and management strategies. The disease has spread globally after the first case was reported in December 2019. It was declared as a pandemic by the World Health Organization (WHO) on March 11, 2020. As per the latest update by the WHO, the cumulative total of over 34.8 million cases with over 1 million deaths has now been reported globally.
The first case in India was reported from Kerala on January 30, 2020. As on July 31, 2020, a total of 2.15 million cases have been reported with 43,379 deaths from all over the country. Maharashtra is most affected with approximately 5 lakh patients and 17,367 deaths. Mumbai metropolitan region with approximately 50,000 cases is one of the ten hotspots identified by the Government of India on April 1, 2020. However, the case-fatality rate has been steadily declining over a period from April 2020 and has been <2% with recovery rate close to 72% as per the data of Ministry of Health and Family Welfare, Govt of India.
Radiology forms an important part in the diagnostic and management protocols of the patients. Chest X-ray (CXR) remains the main modality for screening and follow-up. The radiological findings range from subtle ground-glass opacities to frank florid consolidation correlating with the progression of the dieasase process. The imaging resources used predominantly for the diagnosis are CXR and computed tomography (CT) scans. Various countries have developed the imaging protocols as per their resources. The sensititivity of CXR for the detection of abnormal findings has a varied range (50%–84%) as per the literature., In our study, the positivity rate of radiographs was 50.70%. The progression of findings was seen in 75% of the CXRs with good correlation between clinical and radiological severity. It is well-established that the sensitivity of CT is higher than radiographs (>90%), but decontamination of the suite poses a big challenge. At present, professional societies recommend CXR as the imaging modality of choice while reserving CT for any diagnostic dilemma.,,
The main objective of the study is to assess the patterns and types of radiological involvement on CXR in symptomatic COVID-19 patients to gain scientific perspective about the disease and its correlation with the clinical condition of the patient.
| Materials and Methods|| |
This was a retrospective study which was approved by the hospital review board. The study sample consisted of 449 chest radiographs obtained from 312 symptomatic patients diagnosed as COVID positive by the reverse transcription polymerase chain reaction (RT-PCR) or antibody test and admitted between March and July 2020. The patients were initially clinically evaluated by the clinicians for the symptoms and signs for COVID-19. Patients with a high clinical suspicion for COVID-19 underwent RT-PCR for COVID-19 and relevant laboratory examinations. Those with symptoms such as breathlessness and low SpO2 were referred for chest radiograph. The patients who had deterioration of symptoms underwent follow-up radiographs. The patients who were included in the study were those symptomatic with SpO2<96% and tachypnea of >24/min among tested seropositive for COVID19 infection by RT-PCR on nasopharyngeal swab. Asymptomatic seropositive patients and/or having SpO2 of 97% and above were excluded from the study. The radiographs were obtained using a portable X-ray machine (MARS 6, Allengers). Either standing PA view using a chest stand for stable patients or supine AP view for critical patients was taken. Technical factors of 80–100 kV and 5–10 mAs were used in the vast majority of patients. Images were post processed using Fujifilm computed radiography reader (FCR XG 5000) and were transferred onto the radiology picture archiving and communication system (Centricity™, GE Healthcare). Clinical and relevant laboratory data were retrieved from the electronic patient records of the hospital.
Image acquisition and analysis
All examinations were evaluated for the presence or absence of lesions by two radiologists of 5 and 7 years of experience. In case of disagreement, third radiologist with 13 years of experience was consulted. Lesions were classified into ground-glass opacities (GGOs), consolidations, reticular, etc., as per the Fleischner society's nomenclature. Distribution was described as peripheral or central, unilateral, or bilateral with upper, mid, or lower zone involvement. The presence of pleural effusion, lymphadenopathy, and pneumothorax was looked for. The upper zone was defined as lung field above a horizontal line connecting the inferior margin of the anterior end of second rib and lateral chest wall, mid zone as below upper zone and above horizontal line connecting inferior margin of the anterior end of fourth rib and lateral chest wall, and lower zone as between the mid zone and diaphragm. The central zone was defined as the area 2 cm within the hilum and peripheral zone as within 3 cm of a costal pleural surface. The data was analyzed using PSPP (“GNU Project (2015). GNU PSPP (version 0.8.5) [computer Software]. Free software foundation. Boston, MA”). P < 0.05 was considered statistically significant.
| Results|| |
The mean age of the patients was 43 years ranging from 20 to 81 years. There were 245 (78.53%) male and 67 (21.47%) female patients. Fever, sore throat, and cough were the predominant symptoms. A total of 449 radiographs of COVID-positive patients admitted in our tertiary care hospital was analyzed independently by two radiologists of 5 and 7 years of experience. When there was a difference in opinion, third radiologist with 13 years of experience was consulted, and a consensus was reached.
Pattern and distribution
Among the 312 patients who underwent a total of 449 radiographs, 158 patients (50.7%) showed the abnormal findings on X-rays. There were 46 fatal cases over a duration of study out of symptomatic 312 patients (14.74%). The distribution of positive findings and the fatal cases among various age groups is shown in [Table 1].
|Table 1: Age group wise distribution of positive Chest Xrays and fatal cases|
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Localization and distribution
Lesions were bilateral in 80.37% (127/158) radiographs. Unilateral findings were observed in 19.63% (31/158) of radiographs. Zones involved in the descending order of frequency were as follows: Left lower zone (LLZ) = 88.5%, right lower zone (RLZ) = 82.5%, left mid zone (LMZ) = 78.5%, Right mid zone (RMZ) =72.33%, Right upper zone (RUZ)=20.33%, and Left upper zone (LUZ)=18.35%. A total of 91.71% (145/158) radiographs had peripheral opacities, whereas only 8.39% (13/158) had purely central involvement. The most common pattern noted was consolidations (91.75%) which was seen in 145 out of 158 radiographs. GGOs were seen in 7.5% (12/158). Acute respiratory distress syndrome or total white out/opacification of lung fields was observed in one of the cases among the total radiographs. No lymphadenopathy/pneumothorax was observed. No ultrasonography/CT scan was done for the patients, although there was a CT scan earmarked for COVID-19 patients.
No significant difference was found between the right and left side involvement. Upper zones were least commonly involved compared to the mid and lower zones (P < 0.001) with no isolated involvement. Consolidations were the most common (P < 0.05) and were seen in 91.7% (145/158) patients. Bilateral involvement was the most common (80.3%, 127/158, P < 0.001). The majority of involvement was peripheral in distribution (91.71%, 145/158, P < 0.05), whereas only 8.39% (13/158) had purely central involvement.
Lower zones were the most common involved followed by mid zones. There was significant involvement of LLZ compared to LMZ (P = 0.0003) while no statistical difference was seen between RLZ and RMZ involvement (P = 0.12) [Figure 1], [Figure 2], [Figure 3], [Figure 4].
|Figure 1: Chest X-ray showing peripheral ground-glass opacities in bilateral mid and lower zones|
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|Figure 2: Chest X-ray showing predominantly peripherally distributed interstitial (midzones) as well as alveolar pattern (lower zones) of opacities in bilateral lung fields|
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|Figure 3: Chest X-ray showing confluent peripheral consolidation in bilateral lung fields (left > right)|
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|Figure 4: CXR showing confluent central as well as peripheral consolidation in bilateral lung fields|
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A total of 84 patients (26.9%) were followed up with serial radiographs. The frequency of follow-up radiographs were determined by the clinical and SpO2 evaluations. There were 21 cases (25%) which did not reveal any abnormal findings and remained normal. However, 63 patients (75%) showed findings on the serial radiographs. Out of these, 60.3%. (70/116) showed progression of findings. There were 26 cases (22.4%) which remained static in their findings, whereas the complete resolution of findings was seen in 17.3% (20/116) of cases[Figure 5].
|Figure 5:(a-c) Serial chest X-rays showing the progression of findings on follow-up|
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There were 46 fatal cases over a duration of the study out of symptomatic 312 patients (14.74%). Out of which, 22 patients (47.82%) underwent chest radiographs, and 10 patients (21.73%) were followed up on radiographs. All of the radiographs (100%) showed abnormal findings. The follow-up of radiographs show the progression of findings in eight patients (80%). The most common pattern noted was the progression of the extent of air space opacities from peripheral to central, upper and mid-zonal to lower zonal distribution and bilateral involvement. There was no significant progression of the findings in 02 patients (20%). The maximum number of fatalities (86.94%) was observed in the age group which was >50 years of age. The age distribution of fatal cases is shown in [Table 1].
| Discussion|| |
COVID-19, which was first reported in December 2019 has been declared as a pandemic by WHO. As of date, it is still an evolving disease which is being extensively researched and studied. At present, no definite treatment or vaccine is available, with the mainstay of treatment remaining as oxygen supplementation. Patients may receive treatment involving drugs such as remdesivir, low-molecular-weight heparin, tocilizumab, angiotensin-converting enzyme inhibitors, and hydroxychloroquine based on their clinical condition. Radiology forms an important part in the management protocols of the patients, and different countries have promulgated their own protocols as per the availability of these facilities. CXR remains the main modality for screening and follow-up. China has extensively used CT scans for the management of the patients. Decontamination of the CT suite is a laborious process and will disrupt the emergency care in places were only single scanner is available. American College of Radiology (ACR) and other societies,, recommend CXR as the main modality for COVID-19 patients.
USG of the chest has been described as a portable modality for the bedside monitoring of severely affected patients which is easy to perform and with immediate results. However, decontamination of the machine and exposure to the technician/radiologist is an issue.
Our in-hospital protocol earmarked a portable digital X-ray machine, a portable USG, and one CT scan machine for the use in those with COVID infection or those with a COVID indeterminate status. Further, our hospital protocol recommended CXR as the main imaging modality for symptomatic COVID-positive patients as well as in patients with clinical deterioration. The frequency of follow-up CXRs to be determined by their clinical condition. Our study showed 75% of the patients on follow-up showed abnormal radiographs. Furthermore, all of the fatal cases showed progression of involvement on serial radiographs. CT scan was only reserved for any diagnostic dilemma as per the ACR recommendations.
Pattern and positivitiy of findings
A study by Vancheri et al. analyzed 240 patient's CXRs in a time-dependent manner and had a negativity rate of 25%, whereas a study by Wong et al. showed a negative rate of 31%. Compared to both these studies our study had nearly 50% of patients being negative. This was comparable to Bernheim et al. which showed 56% normal initial CT scans. In our study, the most common lesions were consolidation, while in the study by Vancheri et al. showed GGOs as the predominant pattern, especially after 5 days while reticular opacities were common in initial days. All patients did not undergo follow-up CXR in our institute, unless there was a clinical deterioration. Due to this, a chronological course was not possible to assess. This was a limitation of our study.
Localization and distribution of findings
The distribution of the lesions was consistent with other studies which also showed peripheral, mid, and lower zone predominance.,,, Our study showed 8.39% had purely central involvement which is also similar to the central zone involvement seen from 3% to 14% in study by Vancheri et al. Another limitation of our study was that CT was not routinely performed for all COVID-19 patients and was reserved for any diagnostic dilemma. It is well-established that the sensitivity of CT is higher than radiographs. This has been corroborated by many studies including that by Ducray et al. which showed CT to have a sensitivity, positive predictive value, and negative predictive value of 90.2%, 84.1%, and 92.7%, respectively, with respect to final RT-PCR test for a sample of 694 patients. However, the management of patients was not hampered by the lack of conducting a CT study in any of the patients.
Chest radiographs conducted in this retrospective analysis of patients with laboratory-proven symptomatic COVID-19 infections showed that a little more than half of the patients with the infection had lung consolidations, which in the vast majority had a patchy and peripheral distribution. No statistically significant difference was found between the right and left side involvement. Upper zones were least commonly involved compared to mid and lower zones (P < 0.001) with no isolated involvement. Consolidations were the most common (P < 0.05) and were seen in 91.7% (145/158) of abnormal CXRs. Bilateral involvement was the most common (80.3%, 127/158, P < 0.001) with peripheral zones being most commonly affected (P < 0.001).
The presence of findings correlated well with the clinical severity of the disease. Resolution of findings matched the clinical improvement in status. The majority of findings were seen (71.1%) in patients above 50 years of age. There were 84 patients (26.91%) which were followed up on serial radiographs (137 radiographs) depending on clinical and SpO2 status. Out of these 84 patients, 63 patients (75%) who underwent 116 X-rays showed abnormal findings. Among these, 60.3% X-rays showed the progression of findings during course of hospitalization and 17.4% showed the resolution of radiographic findings.
There were 46 fatal cases, of which 22 patients (47.82%) underwent chest radiographs and 10 patients (21.73%) were followed up on radiographs. All of the radiographs (100%) showed abnormal findings. Among these, the follow-up of 8 patients (80%) showed progression of findings on radiographs. The most common pattern noted was progression of the extent of air-space opacities from peripheral to central, upper and mid-zonal to lower zonal distribution, and unilateral to bilateral involvement.
Our study shows that CXRs have an important diagnostic and prognostic role in the management of patients with the COVID-19 infection. The use of CT scans as a routine tool for screening or evaluation was not required in any of our patients.
| Conclusion|| |
In our retrospective study of 449 radiographs from 312 symptomatic patients, the positivity rate of radiographs in our study group was 50.70%. Among the follow-up radiographs of clinically deteriorating patients, 80% of rays showed the progression of findings. This significantly emphasizes the role of serial radiographs in such patients. This is further established by the fact that all the fatal cases showed progression of radiographic findings. Ultrasound or CT scan was not routinely used and did not influence the clinical course and outcome. Negativity rate of 49.30% indicates that CXR may be avoided for asymptomatic patients as it is unlikely to influence the outcome and will increase the exposure of involved staff. The present study shows that CXRs have an important diagnostic and prognostic role in the management of patients with the COVID-19 infection.
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Conflicts of interest
There are no conflicts of interest.
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