Review for 10.1186/s12876-016-0545-x (2016)

Reviewer ’s report  
 
Title: Clinical Significance of Incidental [18F]FDG Uptake in the Gastrointestinal Tract on 
PET/CT Imaging: A Retrospective Cohort Study  
 
Version: 0 Date: 02 Jun 2016 
 
Reviewer:  Michael  Lin 
 
Reviewer’s report:  
 
General comments:  
 
There are many papers on this topic including several reviews. Focal large bowel uptake on FDG 
PET needing further investigations to exclude dysplastic polyp and colorectal cancer is well 
known.  
 
 
Specific comments:  
 
There is a slight discrepancy between the title and results. I presume the paper is more about 
focal uptake in the GIT. There is very limited description regarding other patterns of uptake (eg. 
diffuse, segmental) and what they turned out to represent or whether further investigations were 
indeed performed.  
 
The methodology section is brief and does not contain sufficient i nformation , eg. the different 
patterns of FDG uptake at different locati ons, should be stated. The tables can be expanded and 
improved.  
 
How was incidental GIT uptake determined? I presume higher than background? How was 
diffuse uptake interpreted, ie. between normal vs abnormal?  
 
It is well known the metformin can cause diffus e reactive bowel uptake and the number of 
patients on this medication would be helpful. Did these patients have diffuse uptake  and did any 
of these patients undergo colonoscopy?  
 
In results, the inclusion of SUV measurements and the T stage of the incident al carcinomas 
found would be helpful.  
 
Intro - page 5 line 36, polyp is a neoplastic condition  
 
Method and Results - Apart from the colorectum, the other sites of incidental GIT uptake needed 
to be clarified. Location? Pattern? Aetiology?  
 
Page 8 - first paragra ph is confusing  
In the discussion "Fasting can increase focal uptake of 18F -FDG as well [16]" - I am uncertain 
this is true and a more recent study to support this statement would be helpful. If not, should be 
taken out.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
No 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any st atistics in the manuscript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
Not relevant to this manuscript  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
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