Delayed Enhancement in Cardiac CT: A Potential Alternative to Cardiac MRI? Technical Updates and Clinical Considerations

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The purpose of the review was to examine the existing about the potential diagnostic and prognostic value of LIE-CT in ischemic and non-ischemic heart diseases.

I have a few comments.

Could the authors add a paragraph about the possible indications of cardiac LIE CT as well as its advantages and disadvantages?

Also, could the authors add some tables with the literature in the distinct pathologies mentioned in the article?

Author Response

Thank you for your suggestions.

1. As recommended, a final paragraph summarizing both the main potential indications in both acute and non-acute settings, as well as the major advantages and disadvantages, has been added.
2. In Table 1, a column has been added listing the main authors investigating the role of LIE-CT in various ischemic and non-ischemic pathologies considered in the review.

Reviewer 2 Report

Comments and Suggestions for Authors

The narrative review by De Stefano and colleagues summarizes existing literature on late iodine enhancement computed tomography (LIE CT) as a potential alternative cardiac imaging modality to MRI in both ischemic and non-ischemic heart diseases. The review is well-presented and easy to read. However, I would suggest creating a new table/ figure, or expanding the existing Table 1, to highlight the strengths and weaknesses of each imaging modality in the cardiac diseases considered.

 

Author Response

Thank you for your comments and suggestions. The strengths and weaknesses of LIE-CT seem to be quite similar across the various types of cardiac pathologies analysed. Table 2 has been added, summarizing the major advantages and disadvantages.

Reviewer 3 Report

Comments and Suggestions for Authors

1. Insert a space between the text and the corresponding reference.

2. The manuscript refers to some clinical studies, but the limitations of these studies, such as sample size, study design or possible biases, are not discussed in detail; this information would be very useful to put the described data into context.

3. This version of the paper provides detailed information on the imaging techniques and results of the studies reviewed. However, the clinical relevance of these findings is not always clearly stated in the manuscript.

4. In some sections of this paper, LIE-CT technologies are compared with LGE-CMR. However, the manuscript focuses mainly on the applications and findings of LIE-CT, with less emphasis on direct comparison with LGE-CMR. It would be helpful if possible differences (clinical or methodological aspects) that make one technique more suitable than another could be specified in these sections.

5. The wording of the manuscript could be improved for clarity and fluency. Some sections are difficult to understand because of unclear wording or lack of clarity in the expression of ideas.

Author Response

Thank you for your feedback.

1. A space has been inserted between the text and the corresponding reference.
2. The text and conclusions have been updated to include the acknowledgment that, despite the overall promising results of the studies included in this review, many of them have limitations, particularly in non-ischemic pathologies. Several studies have a very limited number of patients or are presented as case reports. Future studies with larger sample sizes are needed to validate these findings.
3. We acknowledge the importance of clearly indicating the clinical relevance of the imaging techniques and study findings discussed in the manuscript. Indeed, a paragraph has been added, preceding the conclusions, which summarizes the possible clinical indications in relation to the findings of the studies in the literature, along with the main pros and cons.
4. Direct comparisons with LGE-CMR were primarily delineated in articles where patients underwent both LIE-CT and LGE-CMR, allowing for a comparison of results. In cases where such comparisons were not feasible, the advantages and disadvantages outlined in the aforementioned paragraph apply.
5. We hope that the additional paragraph will help highlight the key points more effectively, thereby enhancing clarity throughout the manuscript.

Reviewer 4 Report

Comments and Suggestions for Authors

Delayed Enhancement in Cardiac CT: A Potential Alternative to Cardiac MRI? Technical Updates and Clinical Considerations

Reviewer Comments: 05 09 2024

At present the gold standard for non-invasive myocardial characterization and fibrosis quantification is CMR-LGE. However, access to this modality is restricted, especially in acute settings and in certain patient populations who are contraindicated for MRI. LIE-CT imaging has emerged as a potential alternative and promising outcomes alongside some disparities compared to LGE-CMR. LIE-CT can be used in diagnosing non-ischemic heart diseases such as myocarditis, HCM and sarcoidosis. Although LIE-CT demonstrates accuracy in detecting certain myocardial pathologies, it has several limitations, such as the inability to detect diffuse myocardial enhancement. Integrating LIE-CT into cardiac CT protocols could enhance its clinical utility, providing valuable prognostic and management insights across a spectrum of cardiac ischemic and non-ischemic conditions.

Strengths:  

1.    Authors did a good job in highlighting the distinction between LGE-CMR and LIE-CT.

2.    Integrating LIE-CT into cardiac CT protocols provides valuable prognostic and management insights across a spectrum of cardiac diseases.

Weakness:

1.    Even though it adds lot of value to include LIE-CT into cardiac protocols, it fails to detect diffuse myocardial enhancement. 

2.    The accuracy of LIE-CT varies and it’s dependent on the imaging protocol, including acquisition timing and contrast administration.

3.    Even though authors claim that integrating LIE-CT into cardiac CT protocols provides valuable prognostic and management insights across a spectrum of cardiac diseases, only few studies support these phenomena and data is lacking.

4.    According to studies LIE-CT has poor resolution and low contrast enhancement. Due to this reason, it will be good to use it in research setting and it may not be viable to replace LGE-MRI. 

 

 

Author Response

Thank you for your thorough feedback and insightful observations. We appreciate your acknowledgment of the distinctions between LGE-CMR and LIE-CT highlighted in our manuscript. Regarding your concerns about the limitations of LIE-CT, we agree that it cannot replace LGE-MRI when available and feasible, and we have made some minor changes in the text to emphasize this point. We acknowledge the current gaps in the literature and have highlighted the need for additional research to comprehensively address these limitations.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

All queries were addressed according to authors suggestions.