21 yo F Cough. Nodule on CXR. Had a CT chest to evaluate the nodule. • Xray of the Week
Figure 1. What is the diagnosis?
Figure 2. CT scan of the chest demonstrating multiple peripheral regions of ground glass opacification.
This case demonstrates pneumonia in a patient diagnosed with COVID-19. In this case, CXR shows a nodule while the chest CT shows extensive disease that is not seen on CXR. CXR is less sensitive than CT in detecting COVID-19 lung disease (1). It is important to note that RT-PCR, not chest CT, is the gold standard in diagnosis of COVID-19.
ACR guidelines state that CT should not be used to screen for COVID-19 and should not be the first-line test for diagnosis of COVID-19 (2). ACR guidelines also state that CT should be used “sparingly and reserved for hospitalized, asymptomatic patients with specific clinical indications for CT.” (2).
COVID-19, like other viral pneumonias, causes lung opacities in more than one lobe bilaterally (1,3). These opacities typically occur in the peripheral lung, which can be seen on CXR (1). CXR can show diffuse lung opacities similar to those seen in inflammatory conditions such as acute respiratory distress syndrome (1).
Common lung findings on CT include ground glass opacities (GGO) with or without consolidation, which can be accompanied by interstitial or interlobular septal thickening (1,4). GGO may also have thickened interlobular septa and intralobular lines appearing as a “crazy paving” pattern (5,6). GGO is not typically perceived on chest radiography so CT is especially important (3). Consolidation due to cellular fibromyxoid exudates in alveoli may occur after 2 weeks and is used to estimate disease progression (6).
Appearance on imaging varies based on stage and severity. Asymptomatic patients with COVID-19 pneumonia show lesions on CT in the peripheral and subpleural areas of the lung, involving one or two lung lobes (4,5). In critical cases, bronchiectasis and bronchial wall thickening are also common with proliferation of fibrous tissue (6). Less common findings have also been reported in the literature, including pleural effusions, lung cavitation, pneumothorax, nodules, diffuse chest wall subcutaneous emphysema, pneumomediastinum, and diffuse alveolar damage (1).
In this case, a solitary nodule was observed on CXR (Figure 2). Nodules are defined as round or irregular opacities measuring less than 3 cm in diameter with well or poorly defined edges (6). They are common in viral pneumonia and 3-13% of COVID-19 patients may have multifocal solid irregular nodules or nodules with visible halo sign (6). Some patients with COVID-19 have only presented with a single small sub-centimeter ground glass nodule with peripheral halo on baseline CT images which could be misdiagnosed (7,8).
Multiple drugs have been investigated as possible treatments. Dexamethasone has been suggested to improve outcomes in patients who are dependent on ventilation, but there is only limited evidence supporting its role in reducing mortality rates (8,9). Remdesevir has been found to shorten recovery time for patients on supplemental oxygen therapy from 15 days in the placebo group to 11 days in the Remdesivir group (10). Although mortality was lower in the Remdesivir group (7.1%) than in the placebo group (11.9%), the difference was not statistically significant (10). An investigational vaccine known as mRNA-1273 has been effective in protecting mice from infection with SARS-CoV-2, and it is now in Phase 3 trials (11). There are several similar vaccine candidates currently in Phase 1-3 trials; however, it is uncertain how long it will take for a vaccine to be FDA approved (12).
Jacobi A, Chung M, Bernheim A, Eber C. Portable chest X-ray in coronavirus disease-19 (COVID-19): A pictorial review. Clin Imaging. 2020; 64:35-42. doi:10.1016/j.clinimag.2020.04.001
acr.org. 2020. ACR Recommendations For The Use Of Chest Radiography And Computed Tomography (CT) For Suspected COVID-19 Infection. [online] Available at: https://www.acr.org/Advocacy-and-Economics/ACR-Position-Statements/Recommendations-for-Chest-Radiography-and-CT-for-Suspected-COVID19-Infection [Accessed 10 August 2020].
Hu L, Wang C. Radiological role in the detection, diagnosis and monitoring for the coronavirus disease 2019 (COVID-19). Eur Rev Med Pharmacol Sci. 2020;24(8):4523-4528. doi:10.26355/eurrev_202004_21035
Meng H, Xiong R, He R, et al. CT imaging and clinical course of asymptomatic cases with COVID-19 pneumonia at admission in Wuhan, China. J Infect. 2020;81(1):e33-e39. doi:10.1016/j.jinf.2020.04.004
Verdecchia, Paolo, et al. The Pivotal Link between ACE2 Deficiency and SARS-CoV-2 Infection. European Journal of Internal Medicine, vol. 76, June 2020, pp. 14–20. PubMed Central, doi:10.1016/j.ejim.2020.04.037
Ye, Zheng, et al. Chest CT Manifestations of New Coronavirus Disease 2019 (COVID-19): A Pictorial Review. European Radiology, Mar. 2020, pp. 1–9. PubMed Central, doi:10.1007/s00330-020-06801-0
Rasekhi, Alireza, et al. COVID-19 Pneumonia Presenting as a Single Pulmonary Nodule in a Kidney Transplant Recipient: A Case Report and Literature Review. Radiology Case Reports, vol. 15, no. 9, July 2020, pp. 1587–90. PubMed Central, doi:10.1016/j.radcr.2020.06.054
Xia, Tianyi, et al. Small Solitary Ground-Glass Nodule on CT as an Initial Manifestation of Coronavirus Disease 2019 (COVID-19) Pneumonia. Korean Journal of Radiology, vol. 21, no. 5, May 2020, pp. 545–49. PubMed Central, doi:10.3348/kjr.2020.0240
Yang, J. W., et al. Corticosteroid Administration for Viral Pneumonia: COVID-19 and Beyond. Clinical Microbiology and Infection: The Official Publication of the European Society of Clinical Microbiology and Infectious Diseases, June 2020. PubMed, doi:10.1016/j.cmi.2020.06.020
Beigel, John H., et al. Remdesivir for the Treatment of Covid-19 — Preliminary Report. New England Journal of Medicine, vol. 0, no. 0, May 2020, p. null. Taylor and Francis+NEJM, doi:10.1056/NEJMoa2007764
Corbett, K.S., Edwards, D.K., Leist, S.R. et al. SARS-CoV-2 mRNA vaccine design enabled by prototype pathogen preparedness. Nature (2020). doi:10.1038/s41586-020-2622-0
NIH-Moderna Investigational COVID-19 Vaccine Shows Promise in Mouse Studies. National Institutes of Health (NIH), 5 Aug. 2020. https://www.nih.gov/news-events/news-releases/nih-moderna-investigational-covid-19-vaccine-shows-promise-mouse-studies
Amara Ahmed is a medical student at the Florida State University College of Medicine. She serves on the executive board of the American Medical Women’s Association and Humanities and Medicine. She is also an editor of HEAL: Humanism Evolving through Arts and Literature, a creative arts journal at the medical school. Prior to attending medical school, she graduated summa cum laude from the Honors Medical Scholars program at Florida State University where she completed her undergraduate studies in exercise physiology, biology, and chemistry. In her free time, she enjoys reading, writing, and spending time with family and friends.
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Kevin M. Rice, MD is the president of Global Radiology CME
Dr. Rice is a radiologist with Renaissance Imaging Medical Associates and is currently the Vice Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.
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