Hello,

I reviewed the manuscript entitled "The evaluation of liver fibrosis in the Real-time Shear Wave Elastography technique in chronic B and C hepatitis patients: how many measurements are necessary to assign patients to Metavir score properly?". The authors evaluated the number of measurements using SWE needed to have a reliable result for evaluation of liver fibrosis. The study results are interesting however I included few comments to improve the presentation of manuscript:

1. This study included 347 patients with HCV, 158 with HBV and 137 healthy subjects. I have major concern regarding the condition and selection of these individuals. It is not clear what is the clinical condition of patients with HBV and HCV infection. Regarding the patients with HCV infection, were they all positive for HCV RNA at the point of assessment? Regarding the patients with HBV, were they receiving treatment? Regarding healthy individuals, why did they referred for liver fibrosis assessment?

2. In the first paragraph of introduction, there are numeric data such as 5.7 kPa +/- 0.75. It is not well-defined what is "+/-" and if it has been used for SD while we accompany median with IQR.

3. Authors stated "There was no statistical difference in liver stiffness between the 2D SWE value of the first measurement and the median value of the first three measurements (p=0.1743, ICC=0.98)" and "ICCI-III=0.9931". Which one is right?

4. In the first paragraph of discussion, authors compared their results with the results of other studies and stated "The median value of liver stiffness reported in our study (6.8 kPa IQR=5.9-8.8 kPa) is higher than in other studies. The average value of liver stiffness reported in this study (8.1 kPa, SD=4.0)". Such numerical data is not available in the result section. Moreover, it is not clear if this data related to the healthy individuals or not. In addition, It is not clear what was the condition of study population in other studies compared in this section of manuscript.

5. In the first paragraph of discussion, the studies which were compared should be cited.

6. In conclusion section, authors stated "To conclude, 2D SWE has a potential to accurately evaluate liver fibrosis in a non-invasive way.". How can they include such statement while there was no gold standard method in parallel with SWE for evaluation of liver fibrosis?

7. In conclusion section, authors stated "At least three 2D SWE measurements presented as the median value should be used to assess liver stiffness properly in patients with chronic liver diseases.". I am not sure which observations of this study support such conclusion.

Regards