Differential Assessment of Internal Jugular Vein Stenosis in Patients Undergoing CT and MRI with Contrast

Round 1

Reviewer 1 Report

In the present manuscript the authors present a study where internal jugular vein stenosis was assessed both by CTA and MRA.

Thank you for the opportunity to review your interesting work!

Below are some comments I would appreciate to be addressed prior to publication:

1. The correlation between MRA and CTA is indeed significant but only with a moderate correlation coefficient ( r < .5). And also the qualitative analysis of your scatterplot reveals quite diverging results.

It is fine if you address this as a significant correlation. However, you ought to point out the level of effect (moderate correlation) and you should supply 95% CIs to your r, otherwise it could be perceived as misleading.

2. Why did you include only cases where both imaging modalities showed a grade I - IV stenosis?

3. What is the role of ultrasound for this application? You consider phlebography as the reference standard but this might be outdated. Do you think IVUS has any merits for this application?

4. You should additionally conduct agreement and inter-method reliability (such as Cohens kappa) analyses to boost the validity and presentation of your findings.

Congratulations on your manuscript!

Author Response

Please see attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear colleagues,

thank you for submitting your paper. Although I enjoyed reading it, I would like to ask you to

- give more information on how much contrast you gave in CT and MRI and on what basis (formula?)

- state the reconstructed slice thickness in CT

- shorten the scanning protocols section by the sequences used for intracranial imaging - you do not refer to them in the results or discussion section

- ad a full stop in line 200 behind reference 10  

Kind regards and best wishes!

Author Response

Please see attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

What you see on the images is most likely collapse of the vein, not stenosis.

To exclude this, e.g. Valsalva manoeuvre should be administered.

Also pt. with relevant symptoms should be compared to pt. without, else it does not make much sense.

Author Response

Please see attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thank you for submitting a thorough response!

I think there was a minor misconception that can be addressed easily.

In your response you are referring to Cohens kappa as a metric to.investigate inter-RATER reliability. However, the comment was about inter-METHOD reliability between MR and CT findings that you assess solely via correlation coefficients.

Relying on correlation coefficients only is ill-advised.

Author Response

We thank the Reviewer for this very helpful clarification. We agree that the calculation of inter-rater reliability between modalities provides stronger support for our conclusions than relying on correlation coefficients only. We are greatly appreciative of the Reviewer’s thoughtful suggestion!

We have calculated Cohen’s Kappa and an associated 95% confidence interval for all stenosis grades (0-IV) as assessed by CT and MRI, respectively. We have updated our Abstract, Methodology,  Results, and Discussion sections accordingly. Specifically, we in our Results section we write:

“Across all IJVS categories (0-IV), there was fair agreement in stenosis grades between CT and MRI (k = 0.220, 95% C.I. = [0.029, 0.410]), though the categorical distributions of IJVS grades indeed differed significantly (c²=27.378, p=0.002).”

We are particularly appreciative of the Reviewer’s suggestion, as we feel that reference to inter-rater reliability gives us the chance to more fully describe the portion of our analysis that takes into account both non-stenosed (i.e. Grade 0) and stenosed (Grades I-IV) veins, which may have been lacking in our initial submission. We therefore would like to thank the Reviewer for suggesting an efficient way to improve the impact of our work.

Reviewer 3 Report

Dear authors

the articles has improved now and is scientifically sound.

Author Response

We thank the Reviewer for taking the time to provide helpful feedback on our work, and are pleased to hear that their concerns have been sufficiently addressed.