Imaging Techniques for Cardiac Function
Round 1
Reviewer 1 Report
In the manuscript ' Imaging techniques for cardiac function,' the authors Vasileios Panis and Erwan Donal reviewed currently used techniques in cardiac function imaging such as echocardiography techniques, CMR, CT and MMI. Full introductions for each technique were given and a list was given to conclude the strengths and shortcomings of each imaging method providing a good reference to the readers. Based on this I just recommend this manuscript accepted as the publication of Applied Sciences. However, the authors still need to answer several questions on this manuscript.
- Even though the authors has reviewed the currently used techniques, the authors are encouraged to discuss about some promising techniques for cardiac imaging such as OCT and photoacoustics in both their advantages and challenges.
- I think 3-D and 4-D are very important features of the imaging, thus the authors should also conclude these in the list.
Author Response
Thank you very much for the positive review of our article.
- For your first question, in this review, we tried to include imaging techniques from the perspective of a cardiac imager(a subspecialty of cardiology) and describe only non-invasive imaging. Nevertheless, multiple imaging techniques are used by interventional cardiologists and electrophysiologists (fluoroscopy, oct, intracoronary echocardiography IVUS, electroanatomical mapping, photoacoustics) which are extremely important. Your remark led me to add a new paragraph (No 9) where I mention the modalities in interventional imaging along with the emerging techniques of deep learning and machine learning.
2. For your second point I couldn't agree more that 3D and 4D features are very useful in current practice and we tried to emphasize their value as part of all the described modalities in 3D TOE,3D TTE, fusion imaging, and interventional echocardiography, 4D flow in CMR, 3D reconstruction in CT. Most of the example images are also 3D or 4D.
I truly hope I have answered your questions
Thank you very much for your input.
Kind regards
Reviewer 2 Report
This is an interesting review on imaging techniques in cardiology and cardiovascular imaging. Structure and language are appropriate. I congratulate the authors to their work.
Comments for author File: 
Comments.docx
Author Response
Thank you very much for your positive review
Kind regards
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
*) The Background Section appears too concise in its contents. Since the work is a review intended for a varied audience, it would be appropriate to expand this part.
*) Physico-mathematical details have not been provided in each diagnostic methodology presented. Perhaps, if the Authors deem it appropriate, it would be interesting to provide some indication of the basic mathematics that support the physics of each diagnostic.
*) The text is rightly littered with acronyms. For this reason, it is considered necessary to insert a table in the text that lists them all exhaustively.
*) No relevant literature references have been associated in Section 7. Please fill this gap.
*) The auditor believes that the reviewed and compared methodologies are interesting. However, often the images to be treated are affected by uncertainties and therefore require fuzzy preprocessing. So, I ask the authors to insert in the text a small section (or even a simple sentence) that highlights this possibility by putting the following relevant works in the bibliography:
doi: 10.1007/s40815-020-01030-5
doi: 10.1016/j.eij.2019.10.005
doi: 10.1016/j.eswa.2020.114361
Author Response
Thank you very much for your review.
1 I agree that the background section could be expanded as there are many historic facts but I would prefer not to elongate the text for the reader to arrive at the main part of the review which is the current and future techniques we use in cardiovascular imaging.
2. Pysico mathematical details would be very interesting to add but the authors come from the medico- cardiology field so it could be a little far-fetched to try to add details out of my main field of expertise.
3.I have added a list of abbreviations at the end f the review
4.I have added the appropriate bibliography in section 7.
5. I have read all three articles and I understood clearly the significance of fuzzy preprocessing, but I found it a little difficult to integrate into the text. I will surely use the mentioned bibliography in future articles. Thank you very much for your input.
Yours sincerely
Reviewer 2 Report
In the paper there are technical information about different techniques, but the role and the advantages of each imaging modality for the evaluation of different aspects of cardiac function (systolic vs diastolic / global vs regional / left vs right) are not addressed.
There is no mention about the stress tests, there are no comments about different parameters (each having advantages and limitations) in the evaluation of cardiac function.
Author Response
Thank you very much for your review.
1. The goal of the paper is to give a summarized overview of the different imaging methods we currently use in cardiovascular medicine for a non- strictly medical audience with a more technical and engineering background so I tried to give a more general approach to the capabilities of each technique.
2.I tried to avoid mentioning specific cardiologic parameters that we are commonly using in everyday practice as well as specific pathologic conditions because then I would have to specialize and explain which imaging technique we use for each different cardiac pathology and why.
3.You were absolutely right concerning stress echo and I added a special mention in the TTE paragraph (Stress echo is my main field of occupation)
4. Finally I added a summarised comparative table of the pros and cons of each technique.
I hope that I have covered your remarks.
Yours sincerely
Reviewer 3 Report
The paper provides a nice overview of the capabilities of imaging modalities used to study cardiac anatomy and function. I find the paper interesting for the community. I would like to make the following two suggestions.
Recently, optoacoustic (also known as photoacoustic) imaging has been suggested as a powerful imaging modality for cardiac imaging. It provides high temporal resolution in three-dimensions (~100 volumes per second) and also provides rich functional information in the form of oxygen saturation readings. Several research studies in mice have shown unique capabilities (see e.g. Lin et al. Characterization of cardiac dynamics in an acute myocardial infarction model by four-dimensional optoacoustic and magnetic resonance imaging. Theranostics, 7(18), 4470 (2017), Ivankovic et al. Volumetric optoacoustic tomography enables non-invasive in vivo characterization of impaired heart function in hypoxic conditions. Scientific reports, 9(1), 1-8 (2019), Ivankovic et al. Volumetric Optoacoustic Tomography Differentiates Myocardial Remodelling. Molecular imaging and biology, 22, 1235-1243 (2020)). The technique can also potentially be used in the clinics as shown e.g. with images of the carotid artery (see e.g. Ivankovic et al. Real-time volumetric assessment of the human carotid artery: handheld multispectral optoacoustic tomography. Radiology, 291(1), 45-50 (2019)). Since the paper provides a perspective on the prospects of new imaging approaches, I think it would be good to mention this.
On the other hand, I would really suggest to include a table summarizing the capabilities of different imaging modalities to get a clearer comparative overview. This can include e.g. spatial, temporal resolution, field of view, contrast type, type of functional information (blood flow, molecular,…),…
Author Response
Thank you very much for your review. it has been extremely helpful.
1.I have read the articles you have proposed and I added an extra paragraph for future and emerging techniques where I mention OA tomography, along with the very promising artificial intelligence imaging analysis techniques.
2. Concerning your second remark, I have also added a comparative table with the main advantages of the different imaging techniques.
Yours sincerely
Reviewer 4 Report
this is well written short review (fast-track) of the cardiac imaging modality.
For each modality (CT, Echo, MRI), one can compose a separate Review. But the Authors did a good job in summarizing the up-to-date status of the most used cardiac modality.
I found that the author performed a good background review, the new noninvasive myocardial work measurements are even well described.
Minor:
I did detect some minor typo or spelling issues, I recommend that a native speaker to re-check the main Text for typos.
Example Line 114, page 4,
urther knowledge over cardiac function has
It should be Further
to avoid such small mistakes and to ensure to deliver your review as well as possible, ask a native speaker or a professional language editing.
other than the minor comment, i can recommend this review for publication
Author Response
Thank you very much for your review, I am most certainly going to correct the spelling errors as well as I will ask for a final check from a native speaker.
The goal of the review is to summarize the main imaging modalities and focus on the new technologies that are emerging and make their entrance into everyday clinical practice.
Yours Sincerely
Round 2
Reviewer 1 Report
All suggestions have been implemented. So, the paper deserves publication.
Author Response
Thank you very much.
Reviewer 2 Report
Thank you for your answer.
Yet, English language and style require minor changes.
Also, the first ultrasound image (Image 1 in the body text) should have a description.
Author Response
Thank you very much for your input,
- I have added the description in the first image .
- I have corrected as many language and style errors as i could find. If you find something that i missed could you point it to me and i will make the appropriate changes.
Yours sincerely
