Article History
Received: 27 June 2019
Accepted: 17 January 2020
First Online: 22 January 2020
Compliance with ethical standards
: Due to the anonymised dataset analysed and the nature of the results, further approval by an ethical committee and informed consent of the patients who had originally undergone the CT scans was not required.
: The authors are members of the UK Ministry of Defence, and permission to publish was obtained prior to submission. The authors of this manuscript know of no known conflicts of interest in the conducting, writing up or promulgation of the findings of this study.