Review for 10.1186/s12876-024-03523-1 (2024)

Title: The Diagnostic Value of Dynamic Contrast-Enhanced Ultrasound for Evaluation of
Tissue Oxygen Status in Rat Hepatoma Model
Version: 1 Date: 12 Oct 2024
Reviewer:  Amira A A Othman
Reviewer's report:
First of all
I want to congratulate the authors on their work. In this study, Jiang et al aim to investigate
the potential of dynamic CEUS for assessing oxygen status in two rat hepatoma models and
found that quantitative Dynamic Contrast-Enhanced Ultrasound parameters correlated with the
oxygen status of the tumor, which could be utilized to predict the tumor tissue pO2.
With a frequency of 2–8% annually, hepatocellular carcinoma (HCC) is the most prevalent
primary liver cancer and the sixth most common malignant tumor worldwide.  It can
occasionally be diagnosed at an advanced stage despite surveillance programs, necessitating
extensive therapeutic efforts involving both locoregional and systemic medications. Computed
tomography and magnetic resonance imaging are the standard radiological methods utilized for
HCC post-treatment monitoring. Four weeks following resection or locoregional treatments, or
three months following the start of systemic medicines, is when the initial follow-up imaging
is carried out. Thereafter, it is done every three months for the first two years. Because of this,
current radiological techniques do not allow for the early identification of a good or poor therapy
response *. Many researchers are interested in the possible use of contrast-enhanced ultrasound
(CEUS) and dynamic contrast-enhanced ultrasonography (DCE-US) in the early evaluation of
response to antiangiogenic therapy or locoregional treatments (chemoembolization) in patients
with advanced HCC. In actuality, DCE-US enables the creation of time-intensity curves via a
quantitative analysis carried out by specialized software, offering an assessment of the variables
connected to neoplastic tissue perfusion and its possible modifications after treatments. Its many
benefits include being highly reproducible, minimally intrusive, and capable of providing critical
assessments of patients' survival, which are necessary for timely therapeutic modifications in the
event of an unsatisfactory response and ultimately for the planning of additional treatment**.
(*: doi.org/10.3390/cancers16030551, ** doi: 10.1016/j.mri.2018.11.012).
The authors tried to contribute to this field of research with new findings, nevertheless, there is
an observation for which sufficient justification must be obtained.
In general:
1. The English writing level is shallow, and it is necessary to seek help from an English language
specialist to correct spelling and grammatical errors in the entire text.
2. Abbreviations must be fully written at the first appearance.
3. The Declarations section should be at the end of the manuscript.
In Title:
4. The authors should consider indicating that the study aims to elucidate the diagnostic value
of contrast-enhanced ultrasound in hepatocellular carcinoma.
In Abstract section
5. The background subsection:
-  Should be the shortest part of the abstract. It should very briefly outline the following
information: What is already known about the subject, related to the paper in question. What is
not known about the subject and hence what the study intended to examine (or what the paper
seeks to present). Please reconstruct it properly.
6.  What is the type of study: a population-based study?
7. In method subsection:
- It would help if you described the aim of your statistical analysis.
In the Introduction section:
8. Newly established guidelines by the Association for the Study of Liver Diseases (AASLD),
Liver Imaging Reporting and Data System (LI-RADS), and the Asian-Pacific Association for
the Study of the Liver (APASL) for diagnosing HCC. Please discuss.
9. The value of CEUS in the diagnosis of hepatocellular carcinoma is controversial. Please
discuss.
10. Why is the partial oxygen pressure of human tissues a crucial parameter?
11. The polarographic pO2 electrode has been considered the ‘gold standard’ for measuring
oxygen tension. Oxygen electrodes for the measurement in tissue and microcirculation are
conventionally based on the classical Clark’s electrode. Please discuss.
In the Methods section:
12.  How could you Differentiate HCC from Other Arterial Enhancing Lesions and other
Washing out Lesions?
13. Statistical analysis:
The Mann–Whitney U test is a nonparametric test and involves the summation of ranks. The
Mann–Whitney U test is applied to independent samples. T-test is used to compare the mean of
a continuous variable between a maximum of 2 groups. The Kruskal–Wallis test is a statistical
test used to compare two or more groups for a continuous or discrete variable. The Wilcoxon
rank-sum test is used to compare two independent samples, while Wilcoxon signed-rank test is
used to compare two related samples, matched samples, or to conduct a paired difference test of
repeated measurements on a single sample to assess whether their population mean ranks differ.
How did you choose the proper test during your result analysis?
In the Results section:
14. In Tables: You can title the statistical test column as “Test of significance” and use U= for
the Mann–Whitney U test, T= for the T-test, and #2 = for the Chi-square test, etc.
15. No need to repeat results between tables and the result section
In the Discussion section:
16. The discussion section is one of the final parts of a research paper, in which an author
describes, analyzes, and interprets their findings. They explain the significance of those results
and tie everything back to the research question(s). In this manuscript, there is confusion between
what should be written in the introduction section and the discussion section. Please reconstruct
the discussion section.
17. What is the difference between dynamic contrast-enhanced magnetic resonance imaging and
contrast-enhanced ultrasound for evaluating tissue oxygen status in the rat hepatoma model?
18. Is there a correlation between contrast-enhanced ultrasound and the immune response in the
rat hepatoma model?
19. What is the clinical value of contrast-enhanced ultrasound for the differential diagnosis of
hepatocellular carcinoma from other liver tumors concerning histopathology?
20. Discuss the novelty of your study in the notion of others' studies.
In the conclusion section:
21. Conclusions aren’t simply an overview of a paper. Instead, they should reiterate why your
research is important.