Radiographic Features of COVID-19 in Children—A Systematic Review

Round 1

Reviewer 1 Report

Some comments are as below:

1. Abstract: It is suggested to increase the advantages of the proposed method in terms of experimental data, such as how much better it is than others.

2. Section 1: It is suggested to add a paragraph specifically on the innovation of the paper.

3. Section 1: It is suggested to highlight the research motivation of this paper in the abstract and introduction. That is, why to study the work of this paper.

4. Section 2: The following works related to data extraction are recommended to be discussed:

1) Change detection in landsat images using unsupervised learning and RBF-based clustering, IEEE Transactions on Emerging Topics in Computational Intelligence

2) Viewpoint-based kernel fuzzy clustering with weight information granules. IEEE Transactions on Emerging Topics in Computational Intelligence

5. Section 3: What is the meaning of (6), (13) in Table 1?

6. Section 3: What conclusions can be drawn from Tables 1 to 3?

7. “5. Limitations.” -> “5. Limitations”

8. Section 6: Please say about your future work plan.

Author Response

Thank you for reviewing our manuscript and for providing very helpful comments. We would like to provide the following responses to your comments / suggestions.

1. Abstract: It is suggested to increase the advantages of the proposed method in terms of experimental data, such as how much better it is than others. This suggested was not clear. We have, however, tried to interpret your points and have modified the abstract accordingly. 
2. Section 1: It is suggested to add a paragraph specifically on the innovation of the paper. Thank you, this has been added and has been highlighted within our revised manuscript. 
3. Section 1: It is suggested to highlight the research motivation of this paper in the abstract and introduction. That is, why to study the work of this paper.Thank you, this has been clarified within the abstract and introduction and has been highlighted within our revised manuscript. 
4. Section 2: The following works related to data extraction are recommended to be discussed. Apologies but we could not understand how publications from the IEEE on Landsat images and viewpoint-based kernel fuzzy clustering could be relevant to a systematic review on the CXR appearances of COVID-19 in children. We would be happy to receive further guidance on this point but have not made and changes within our revised manuscript. 

5. Section 3: What is the meaning of (6), (13) in Table 1? These are citations of the relevant references. We believe that they do conform to the standard of the Journal.
6. Section 3: What conclusions can be drawn from Tables 1 to 3?
7. “5. Limitations.”-> “5. Limitations” Thank you, amended. 
8. Section 6: Please sayabout your future work plan. Thank you, added. 

Reviewer 2 Report

Line 62- remains less clear it is not the best formulation, as we know the lung abnormalities observed in COVID-19 lung disease, in children. You should explain the difficulties to evaluate lung disease as a whole, defining COVID-19 syndrome in children.

 Line 179-I would have liked you to classify these patients according to the day of hospitalization in which these changes were present.

Line 185-the same for table 5, I would like to associate the presence of changes related to imaging with the clinical moment (day of admission) for accuracy.

I could also see a statistic related to these parameters, hospitalization (day) and imaging changes. and a statistical correlation. With graphics.

Line 250 -we can certainly complete the discussions with the results you will get from these correlations that I talked about.

would also like to associate correlations about age and the appearance of these changes in children's lungs, is it related to the waves and a certain strain? It would be important to specify if at least the period and when it affected the respective area, with the type of strain, is known.

Line 267 please, let's find particular aspects from different areas and highlight certain particularities of the COVID-19 infection. Did sex or age, or comorbidities, affect certain categories of children? if so in what way?

Author Response

Thank you for your helpful comments. Please find the following responses detailed below. 

1. Line 62- remains less clear it is not the best formulation, as we know the lung abnormalities observed in COVID-19 lung disease, in children. You should explain the difficulties to evaluate lung disease as a whole, defining COVID-19 syndrome in children. Thank you, this extra detail has been added. 
2.  Line 179-I would have liked you to classify these patients according to the day of hospitalization in which these changes were present. We appreciate this suggestion, many of these data points were not available. We have added the extra detail where possible and also acknowledged this as a limitation / future possibility. 
3. Line 185-the same for table 5, I would like to associate the presence of changes related to imaging with the clinical moment (day of admission) for accuracy. We appreciate this suggestion, many of these data points were not available. We have added the extra detail where possible and also acknowledged this as a limitation / future possibility. 
4. I could also see a statistic related to these parameters, hospitalization (day) and imaging changes. and a statistical correlation. With graphics. This would be a challenge and was not a specific focus of our systematic review. Hospitalization day might be less relevant when compared to the day that the patient came systematic. We accept that this is a valid point and have suggested this as future work. 
5. Line 250 -we can certainly complete the discussions with the results you will get from these correlations that I talked about. Thank you, we have included commentary in the Discussion section to this regard.
6. Would also like to associate correlations about age and the appearance of these changes in children's lungs, is it related to the waves and a certain strain? It would be important to specify if at least the period and when it affected the respective area, with the type of strain, is known. We fully agree with these comments but would politely like to point out that this is a systematic review of published peer-reviewed articles. Data reported within these studies is highly heterogenous and as such many of these variables were not reported. We have added commentary to reflect this.
7. Line 267 please, let's find particular aspects from different areas and highlight certain particularities of the COVID-19 infection. Did sex or age, or comorbidities, affect certain categories of children? if so in what way? Again, please understand that this was a systematic review of previously published data. Due to the relatively low numbers and the limited nature of the data published if was not always easy / possible to provide this level of analysis. We again have added commentary to the manuscript to reflect this.