On the top of the dialog there is the content tab control that allows you to select the kind of information you want to see (all, patient information, series information, physician information or image details).
Hide zero length fields checkbox
Use this check box to show or hide tags which have no information, in order to minimize the length of the list.
Hide private fields checkbox
Use this check box to show or hide tags which belong to the machine vendor, in order to minimize the length of the list. These tags are not described in the DICOM standard and there is no "Tag Name" (or Description) for these, unless the user has loaded an external dictionary.
Export to text file button
Press this button to save the header information to a text file. The program always saves the whole header regardless of the content tab current selection. The text file can be opened with notepad.
Help button
Displays this help content.