Applying Taguchi Methodology to Optimize the Brain Image Quality of 128-Sliced CT: A Feasibility Study

Round 1

Reviewer 1 Report

The improvements introduced by the authors in this revised version answer to all my concerns int he previous review, and beyond. 

The paper is clear in the contents, and is likely to contribute to the improvement of protocal optimization in CT scan protocols.

 

Minor issues:

Lines 248/249: text  listing values that are also present in Table 3

Table 3:  experiment 1's values is in bold and separated by a line from  the other experiments

Author Response

Dear Professor:

 

  Thank you for your reply about our submitted manuscript “Applying Taguchi methodology to optimize the brain image quality of 128-sliced CT: a feasibility study”, Manuscript ID: applsci-1681126. I have thoroughly revised and rewrite the manuscript in RED, following statements are the specific responds to your comments for more easy understanding. Thanks again for your editorial works and look forward to hearing from you soon.

 

Regards,

 

Yours sincerely,

 

Chien-Yi CHEN

 

 

11

Lines 248/249: text listing values that are also present in Table 3

[reply] We have revised and deleted “Table 3 based on the Taguchi design shows the optimal experiment for CT was experiment 6. Experiment 10 yielded the worst grade of 14.00 with a standard deviation of 7.50, converted to a η value of 22.92 dB.” at P14L3-5 for easy study.

 

12

Table 3:  experiment 1's values is in bold and separated by a line from the other experiments

[reply] Thanks for the reminding, we revised and added experiment 1's values is in bold and separated by a line from the other experiments in RED at P15,

 

Author Response File: Author Response.pdf

Reviewer 2 Report

I can notice the improvement in the whole manuscript 

There is minor modifications to be done 

• The new abstract is informative. However, the last sentence in the abstract is quite general and I think it is need elaboration (you may rephrase it or provide a result). It is also good to put a conclusion sentence in the abstract showing the impact of the outcome of current study in the field.
• The beginning of the parameters in table 1 should be in capital letter 
• The caption in table 2 has wired written style when express the array size.
• Table 3: the footnote seem to be confusing. It could be read 26 instead of 6 in the experiment column. I suggest using mark instead of numbers. 
•  Figure 3 need to enhanced in term of resolution. I t was better in the 1^st draft.
• I suggest to add a sentence as direction for future work or limitation of the current study in the conclusion 

 

Author Response

Dear Professor:

 

  Thank you for your reply about our submitted manuscript “Applying Taguchi methodology to optimize the brain image quality of 128-sliced CT: a feasibility study”, Manuscript ID: applsci-1681126. I have thoroughly revised and rewrite the manuscript in RED, following statements are the specific responds to the reviewer’s comments. We re-plot Fig 3 to more easy understanding. Thanks again for your editorial works and look forward to hearing from you soon.

 

Regards,

 

Yours sincerely,

 

Chien-Yi CHEN

 

 

21

The new abstract is informative. However, the last sentence in the abstract is quite general and I think it is need elaboration (you may rephrase it or provide a result). It is also good to put a conclusion sentence in the abstract showing the impact of the outcome of current study in the field.

[reply] Thanks to reviewer 2 for the solidified suggestions. To further emphasize the elaboration of this manuscript, we have revised and added “The effective dose (H_E) is about arise approximately 1.33 mSv.” at P2L14-15.

 

22

The beginning of the parameters in table 1 should be in capital letter

[reply] Thanks to reviewer 2 for the solidified suggestions. We have revised and added capital letter in RED in table1 at P9L5.

 

23

The caption in table 2 has wired written style when express the array size.

[reply] Thanks to reviewer B, we have revised and rewrote table 2 added a red line to express the array size in RED in table1 at P9L8.

 

24

Table 3: the footnote seem to be confusing. It could be read 26 instead of 6 in the experiment column. I suggest using mark instead of numbers.

[reply] Thanks to reviewer 2, we have revised and added mark * to avoid confusing in RED in table 3 at P15.

 

25

 Figure 3 need to enhanced in term of resolution. I t was better in the 1st draft.

[reply] Thanks to reviewer 2, I replotted “Figure 3” at P16 for better resolution.

 

26

I suggest to add a sentence as direction for future work or limitation of the current study in the conclusion

[reply] Thanks to reviewer 2, we have revised and added “either choosing the S/N ratio as the metric or presenting the inappropriate orthogonal array” at P25L12-13 for easy understanding.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Thank you for reviewing the paper following the suggestions proposed

Author Response

Dear Professor:

 

  Thank you for your reply about our submitted manuscript “Applying Taguchi methodology to optimize the brain image quality of 128-sliced CT: a feasibility study”, Manuscript ID: applsci-1681126. I have thoroughly revised and rewrite the manuscript in RED, following statements are the specific responds to the reviewer’s comments. We re-plot Fig 3 to more easy understanding. Thanks again for your editorial works and look forward to hearing from you soon.

 

Regards,

 

Yours sincerely,

 

Chien-Yi CHEN

 

 

 

 

Author Response File: Author Response.pdf

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 paper describes the methods and results for optimization of Brain CT acquisition parameters using Taguchi design and a costumed phantom.

Several issues deserve clarification in the manuscript:

• The most important issue has to do with the aim of the paper. The main goal of the work and its relevance aren't clear enough: is it to optimize scanning parameters? Is it to present a methodology for defining the optimal acquisition parameters? Is it to develop a new phantom? In any of the cases, why is it important and where is the novelty when compared to similar works? The goal of the paper must be reframed. 
• The reference to injuries as a result of accidents as a driver for the work seems unnecessary. The presented work can be applied to any brain CT acquisition, regardless of the clinical application. Furthermore, the paper doesn't present any example of specific application to clinical images, only phantom images. 
• The paper emphasizes the use of the Taguchi analysis in medical imaging. Therefore, a more comprehensive description of the method and its applications in medical imaging should have been provided.  This would also eventually allow for the presentation of some degree of innovation in the presented work.
• The authors describe a customized phantom used in the paper. However, the need to use this phantom and not a standardized one isn't sufficiently justified. 
• In the results section, the values of the effective dose HE represent a 66% and 25% increment with respect to the routine examination (2.01 mSv), for the Taguchi experiment (3.34 mSv) and optimal experiment( 2.51 mSv), respectively. The authors argue that these values are below the ICRP limits, but they only refer to the annual limits. This needs a better justification. Eventually, a more fair comparison would be with the available Diagnosis Reference Level. 

Other minor issues:

• the text immediately after equation (1) misses the explanation of variable m (although the following paragraph refers to the m value).
• The legend of Figure 5 is incomplete: A, B, C missing in the image. The legend doesn't clarify the difference between the upper and the bottom rows. 

   

 

Reviewer 2 Report

The optimization of CT protocols is undoubtedly interesting in the field of emergency radiology. The paper tries to tackle the problem in a structured way.

The main methodological limitations are:

1. Phantom: 
   1. Why was non-cylindrical geometry chosen for a tomographic modality?
   2. How does the photon attenuation path impact on image quality?
   3. Have multiple scans been performed by changing the orientation of the phantom?
   4. How was the quality of the slits checked?
   5. Why was a high contrast (air / PMMA) line pair test chosen? Probably working on brain CT it would have been more appropriate to work on a low contrast module.
2. Taguchi Design:
   1. there is no serious comparison with reference [8]
   2. how was the selection of the scans parameters made?
   3. What role do reconstruction algorithms (Iterative, AI-based) play in protocol optimization? (in 2021 they must be evaluated)

The analysis appears to have been done correctly, but methodological limitations impact the results and conclusions.

Reviewer 3 Report

 

• In the abstract: I believe it written as an introduction style you could change "In recent years, injuries as a results of accidents have been among the top ten leading causes of death at Taiwan. Traffic accidents are the most common." to "injuries as a result of traffic accidents have recently been among the top ten leading causes of death at Taiwan."

 

• In the abstract: In addition, I think it would be better to shorten the abstract to 200 words as there is unnecessary information in the abstract such as "three well-trained radiologists"

 

• The sentence in abstract should not be cut and paste from the manuscript.

 

• In the introduction: It could be enhanced and the first paragraph need to be rearranged

 

• In the introduction: there should be explanation for Taguchi Design and its importance. Therefore, it could be deleted from (2.3.) or shortened

 

• Figure3 should be improved in term of resolution

 

• Discuss the limitations of the current investigation in the conclusion and future direction of this study