Review for 10.1186/s12876-022-02389-5 (2022)

Title: CT enterography for evaluation of disease activity in patients with ileocolonic Crohn's
disease
Version: 1 Date: 28 Feb 2022
Reviewer's report:
This is an interesting paper. However, the authors need to make some improvements, especially
in the discussion section. The result and methodology sections need further elaborations and
could benefit from simplifications by the use of more diagrams/tables.
Detailed review is as below:
Abstract:
1. In background section, add at least one line about need for such a scoring system.
2. First mention of an abbreviation should also have the full-form.
3. Whenever, the statistical tools show a value of 0.000, it should be written as (< 0.001).
4. Details about calculation of CTEIA, should be in the methodology section.
5. In conclusion section, it will be better to write in terms of feasibility and strength of this score
(instead of a strong statement proclaiming the score as accurate); as the sample size is small and
such scoring system will need to validated in large samples.
Background:
1. “Treat to target” is a proposed strategy. Also include relevant guidelines, which are routinely
in use, including role of imaging in “exit strategies”.
2. Include citations for “CDEIS” and “SES-CD” being “gold standards”. While “SES-CD” has
not been validated in large sample; “CDEIS” has limitations when only 1 out of 5 segments are
involved and can under-estimate the disease.
3. Please use a more relevant citation in place of “citation number 6”, which is primarily focussed
on “small-bowel diseases beyond Crohn’s disease”.
4. Please include a statement about complementary nature of CTE/MRE to Endoscopy, so as to
accurately define the accepted role of these cross-sectional modalities.
Patients and methods:
1. Why was HBI used in place of CDAI, when the latter is preferred for clinical trial setting.
HBI is only an approximate simplification of CDAI, for clinical setting but not for studies.
2. In your CTE protocol, there is no mention of use of any anti-motility agent. Do you think the
quality of your studies would have been impacted by its omission?
3. Did all patients, who were included retrospectively had good quality CTE images (quality
scoring in terms of distension, contrast administered, etc.)? Was clinical data available for all
the patients (did you exclude any patients who did not undergo colonoscopy within 24 hours)?
Did you exclude any studies for lack of requisite data or for low quality images? - Please add a
flow-chart of your inclusion and exclusion process. It is difficult to imagine that relevant data
and scan quality were available for every patient in the stipulated time period.
Results:
1. Why were the patients with incomplete ileo-colonoscopy not excluded? How did the authors
correlate CT findings in non visualised segments (endoscopy) in these patients?
2. Whenever, the statistical tools show a value of 0.000, it should be written as (< 0.001). Also
mention the statistical test used along with the p-value.
3. Correct the signage of SD (use + instead of +).
4. Also include the sample size evaluated as “n = ? ” for clarity, when comparing different
segments as disease/involvement was not present in all patients.
5. Did the data for attenuation follow normal distribution? There are some cases where SD is
very high. Would median had been a better measurement instead?
6. Maintain consistency in reporting p-values (to three or two decimal points).
7. In the second paragraph of section “predictors of disease activity and severity in CTE”, more
clarity is needed. What was the score based on mural thickness and stratification? Also, with
ROC-analysis, include values of SE and p-value. Finally, in ROC-analysis, the sensitivity and
specificity are for specific cut-offs, which are not mentioned.
8. In the above mentioned section, clarify which values are for univariate and which are for
multi-variate analysis (if conducted).
9. What was the association between the mural thickness and mural stratification? Were these
two parameters independent of each other?
10. Again in the paragraph mentioned above, you have repeatedly used the term “accuracy”
and given values for “sensitivity and specificity”. Please rewrite the sentence or give actual
calculated value for accuracy.
11. After determining mural thickness, stratification and comb sign to be independent predictors
of CDEIS, how was CTEIS calculated? Elaboration is needed in the results section. Additionally,
this can be elaborated in the statistical analysis section, along with the method of censoring in
Tobit analysis.
12. Clarify as to why Spearman index was preferred over Pearson index.
13. Some analysis on the radiation dose delivered to the patient would be beneficial for this
study so as to apprise the clinicians/readers of the radiation burden, which seems to be a major
drawback of this modality over MRE. Data should be easily available from the collected studies.
14. Since this was a retrospective study, why was CTEIA not correlated with patient prognosis,
likely impact on patient management and follow-up?
Discussion:
1. The first three paragraphs can be shortened.
2. Additional paragraphs on the likely impact of such score on patient management, benefit over
MRE and likely methods to reduce radiation burden are needed.
3. Some data on use of PET/CT and PET/CTE should be included. How will these investigations,
which are increasingly being evaluated to differentiate active from inactive disease impact the
need for a CTE based scoring system?