Updates are available Correction dated 2018-07-04

Article History

Received: 21 October 2017

Revised: 21 February 2018

Accepted: 27 February 2018

First Online: 9 April 2018

Change Date: 4 July 2018

Change Type: Correction

Change Details: The original version of this article, published on 09 April 2018, unfortunately contained a mistake. The following correction has therefore been made in the original: The presentation of Fig. 2 was incorrect, “Cotton ball sign” was mistakenly named “Polka-dot sign”.

Compliance with ethical standards

:

: The scientific guarantor of this publication is Jeong Min Lee.

: The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.

: No complex statistical methods were necessary for this paper.

: Written informed consent was waived by the Institutional Review Board.

: Institutional Review Board approval was obtained.

: • retrospective• diagnostic or prognostic study• performed at one institution