Open Dialog Window in Parent Frame

I have a page viewer web part on my page which is surfacing a News page from another part of our SharePoint farm.  This News page contains links to many articles which I have told to open in a Dialog window using the following code:

function DisplayArticle(url)
{
var options = SP.UI.$create_DialogOptions();
options.width = 900;
options.height = 800;
options.url = url;
SP.UI.ModalDialog.showModalDialog(options);
}

This is working fine although the dialog opens within the boundary of the Page Viewer web part and I would like it to open as if it was a dialog of the parent window.

Any thoughts?