Dear Editor,
We have read with great interest, the recent article published in Korean Journal of Radiology titled “Characteristics of COVID-19 patients who progress to pneumonia on follow-up chest radiograph: 236 patients from a single isolated cohort in Daegu” [1]. The authors observed that 35% (59/167) of their patients hospitalized with COVID-19 and initially classified as negative for pneumonia on chest X-ray (CXR) showed a positive conversion at follow-up [1]. Additionally, they identified that age ≥ 45 years (odds ratio [OR]: 3.93, 95% conflicts of interest [CI]: 1.76–8.75, p = 0.001), absolute lymphocyte count < 1500 cells/µL (OR: 2.25, 95% CI: 1.03–4.89, p = 0.041), and C-reactive protein > 0.5 mg/dL (OR: 3.91, 95% CI: 1.54–9.91, p = 0.004) were independent factors related to this conversion [1].
We are aware of various imaging studies used to monitor response treatment because it can reveal the evolution of lung involvement and, therefore, evaluate therapeutic interventions' efficacy [2]. Consequently, in June 2020, WHO published a quick guide for the use of chest imaging in COVID-19, where it recommended its use to indicate therapeutic management in hospitalized patients with suspected or confirmed COVID-19 [3].
However, not all countries have the availability of sophisticated studies, such as in South Korea, where alternative imaging modalities may be chosen. For example, in Peru, 90% of reference hospitals had CXR, and only 42% had computed tomography (CT) [4]. Given this scarcity, we must know the benefits and limitations of each study, mainly due to its applicability in limited CT access contexts.
CXR is a suitable alternative because it has essential advantages such as lower cost and radiation, requires fewer human resources, and minimizes the mobilization of hospitalized patients [5]. Likewise, its portable version shows a particular application by reducing the risk of transmission and the need for constant disinfection of procedure rooms, significantly allowing sequential evaluation [6].
In conclusion, although there is still uncertainty about the usefulness of CXR, it could be used for the individualized follow-up of hospitalized patients with COVID-19 in settings with limited access to CT because it identifies a significant proportion of positive conversions to COVID-19 pneumonia [1].
Acknowledgments
The authors thank the midwife Elkie Johanna Henrica Renders for her support in verifying the English language.
Footnotes
Conflicts of Interest: The authors have no potential conflicts of interest to disclose.
- Conceptualization: all authors.
- Methodology: Victor Velásquez-Rimachi.
- Project administration: Sandra S. Chavez-Malpartida.
- Resources: Luis Campos-Ramirez.
- Supervision: Luis Campos-Ramirez.
- Writing—original draft: Sandra S. Chavez-Malpartida, Randy Velasquez-Fernandez.
- Writing—review & editing: Victor Velásquez-Rimachi, Luis Campos-Ramirez.
References
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