Review Reports - Identification of Traumatic Bone Marrow Oedema: The Pearls and Pitfalls of Dual-Energy CT (DECT)

Round 1

Reviewer 1 Report

Although the paper seems interesting, I am not a radiologist, therefore I cannot judge its content, which does not include any statistical analysis or any diagnostic accuracy measures.

The conclusions of the paper could be expressed as a personal opinion, otherwise they should be supported by data of an appropriately designed clinical trial.

Author Response

Dear Editor and dear Reviewers

This is a point to point rebuttal letter regarding the review of the manuscript entitled

Identification of Traumatic Bone Marrow Oedema: The Pearls and Pitfalls of Dual-Energy CT (DECT)

All the changes requested/suggested were indicated in the manuscript with tracking change mode and discussed in this letter.

REVIEWER 1

Although the paper seems interesting, I am not a radiologist, therefore I cannot judge its content, which does not include any statistical analysis or any diagnostic accuracy measures.

Authors: thank you for your comment. The paper is intended as an image-driven essay, focusing on the possible use of DECT in clinical practice. For this reason, the paper lacks any statistical analysis or any diagnostic accuracy measures. However, some interesting papers were indicated in the reference list, possible examples of diagnostic accuracy studies regarding the topic.

REVIEWER 1

The conclusions of the paper could be expressed as a personal opinion, otherwise they should be supported by data of an appropriately designed clinical trial.

Authors: thank you for your comment. We agree with you that the conclusion should be supported by data and results. In this case, being a pictorial essay, we will change the conclusion to let it sound as a personal opinion, as follows:

“In our opinion, DECT represents a readily available, artifact-free imaging tool capable of identifying BME and associated bony and soft tissue imaging findings in traumatic settings. ”

Reviewer 2 Report

The essay ”Identification of Traumatic Bone Marrow Oedema: The Pearls and Pitfalls of Dual-Energy CT (DECT)” by Foti and colleagues illustrates strengths and limitations of DECT, educationally visualized by means of appropriate cases which were retrospectively chosen and accessed. The figure legends exhaustively explain the images and make these self-explanatory. The aim of the essay is clearly laid out, the logic straight, and the conclusions balanced.

The abstract could be extended by naming some concrete strengths and limitations as other researchers will make use of the abstract as gatekeeper as to whether retrieve and use this neat piece of work when accessing it via a major database.

I guess multimodality diagnostic procedures like PET/CT or PET/MR do not play any role in the identification of traumatic bone marrow oedema? Please evaluate whether the following two references could be beneficially added in terms of delineation of DECT from such multimodality diagnostics procedures (which obviously share the same disadvantage of inapplicability in claustrophobic patients).

Bhure U, Roos JE, Strobel K. Osteoid osteoma: multimodality imaging with focus on hybrid imaging. Eur J Nucl Med Mol Imaging. 2019 Apr;46(4):1019-1036. doi: 10.1007/s00259-018-4181-2.

Bel-Ange A, Tal S, Rapoport M. A Rare Case of Spinal Sarcoidosis Presenting as Multiple Bone Marrow Oedematous Lesions. Eur J Case Rep Intern Med. 2018 Aug 28;5(8):00907. doi: 10.12890/2018_00907.

Minor proposals and corrections

line 5-7. I guess department names should be capitalized; Department of Radiology and so on.

l.16-17. After the first sentence, a brief description of BME would be beneficial to readers less familiar with the indication, meaning in the spirit of, for instance, https://www.healthline.com/health/bone-marrow-edema

l.30: delete comma in “such as, a large”

l.65 and other places: please check with the Information for Authors and recent publications of Tomography if figures should be referenced as Figure X or Fig. X or (as given in the text) figure X.

l.67 delete comma in “BME, than”

l.75 delete comma in “images, in order”

l.99 put comma into “method, whereby” (in order to make “whereby…green” an insertion)

l.224 replace colloquial “didn’t” by more formal “did not”, thanks

l.231 replace “aninomously” by “anonymously”

Author Response

Dear Editor and dear Reviewers

This is a point to point rebuttal letter regarding the review of the manuscript entitled

Identification of Traumatic Bone Marrow Oedema: The Pearls and Pitfalls of Dual-Energy CT (DECT)

All the changes requested/suggested were indicated in the manuscript with tracking change mode and discussed in this letter.

REVIEWER 2

Authors: thank you for your comment.

REVIEWER 2

Authors: thank you for your comment. As suggested by the Reviewer 2, the abstract was modified to include major strength and limitations o DECT in clinical practice.

“Abstract: Dual-energy computed tomography (DECT) has been reported to successfully identify bone marrow oedema (BME) in various traumatic settings. DECT has multiple strengths, including the availability of both 3D view of the anatomical area studied, and of high-resolution super-imposed Dual Energy specific maps onto conventional grayscale morphological images. Windowing can be used to enhance the visualization of BME, by increasing the level of super-imposed images. Conversely, by decreasing the level of super-imposition of colour-coded images, is possible to progressively enhance the visualization of fine anatomical details, useful for diagnosing associated imaging findings. Importantly, bone sclerosis may represent an important pitfall for DECT, potentially generating both false positive and false negative findings, by locally altering CT numbers. The aim of this paper is to evaluate the strengths and limitations of DECT in accurately detecting traumatic BME, by considering practical approaches to imaging at several anatomical sites.”

REVIEWER 2

Bhure U, Roos JE, Strobel K. Osteoid osteoma: multimodality imaging with focus on hybrid imaging. Eur J Nucl Med Mol Imaging. 2019 Apr;46(4):1019-1036. doi: 10.1007/s00259-018-4181-2.

Bel-Ange A, Tal S, Rapoport M. A Rare Case of Spinal Sarcoidosis Presenting as Multiple Bone Marrow Oedematous Lesions. Eur J Case Rep Intern Med. 2018 Aug 28;5(8):00907. doi: 10.12890/2018_00907.

Authors: thank you for your suggestion. I read the suggested papers with great interest. However, both papers focus on non-traumatic conditions. I believe that these papers could be beneficially added in a paper describing other non-traumatic diseases such as stress-insufficiency fractures or focal bone lesions.

REVIEWER 2

Minor proposals and corrections

line 5-7. I guess department names should be capitalized; Department of Radiology and so on.

Authors: thank you for indicating these corrections. The corrections were made as suggested.

Authors: thank you for the suggestion. a brief description of BME was included as follows, in the introduction section:

“BME is typically a response to an injury such as a fracture or conditions such as osteoarthritis. It occurs when fluid builds up in the bone marrow.”

l.30: delete comma in “such as, a large”

Authors: comma removed

l.67 delete comma in “BME, than”

Authors: comma removed

l.75 delete comma in “images, in order”

Authors: comma removed

l.99 put comma into “method, whereby” (in order to make “whereby…green” an insertion)

Authors: done

l.224 replace colloquial “didn’t” by more formal “did not”, thanks

Authors: done

l.231 replace “aninomously” by “anonymously”

Round 2

Reviewer 1 Report

You have stated that:

"Dual-energy computed tomography (DECT) has been reported to successfully identify bone marrow oedema (BME) in various traumatic settings. The aim of this paper is to evaluate the strengths and limitations of DECT in accurately detecting traumatic BME, by considering practical approaches to imaging at several anatomical sites."

Therefore, you need to support your evaluation with diagnostic accuracy measures, even simple ones (e.g. sensitivity, specificity).

Author Response

Dear Editor and dear Reviewer

This is a point to point reply regarding the second revision of the manuscript entitled

Identification of Traumatic Bone Marrow Oedema: The Pearls and Pitfalls of Dual-Energy CT (DECT)

All the changes were indicated in the manuscript with tracking change mode and discussed in this letter.

Reviewer

Therefore, you need to support your evaluation with diagnostic accuracy measures, even simple ones (e.g. sensitivity, specificity).

Authors: thank you for your comment. We included 2 short paragraph summarizing the average diagnostic accuracy measures of DECT in detecting BME around the body. The first was included at the end on introduction.

“In recent metanalyses, DECT achieved high diagnostic accuracy values for the detection of BME (sensitivity, 85%; specificity-97%). Importantly, DECT showed excellent diagnostic performance for both the spine/appendicular skeleton (sensitivity-84%/84%; specificity-98%/93%) (12-13).”

Additionally, another sentence was included at the end of paragraph 3.

“Furthermore, DECT seems to be more accurate in diagnosing severe BME than milder, subtler oedema (8). In selected cases, the quantitative assessment of DECT numbers, using an ROI in areas of less obvious BME, can help in achieving a differential diagnosis. However, thresholds may vary widely, depending on the anatomical area being evaluated, the age of the patient, and the imaging parameters used. Overall, qualitative assessment (sensitivity-85%; specificity-97%) is more accurate than quantitative assessment (sensitivity-84%; specificity-88%) (12-13).”

These accuracy values are in line with the recent literature.

Round 3

Reviewer 1 Report

The manuscript has been improved.