The content type CMS_IMG prints src attribute of a image, which is set through CMS_IMGEDITOR content type.
The usage is very simple. Put CMS_IMG tag in src attribute in your module like below.
Note
If you are using more then one CMS_IMG per article, you have to change/increment index of the next CMS_IMG .
$src = "CMS_IMG[1]"; echo '<img src="'.$src.'" alt="no picture found" />';