Replacing widget titles with an image

Ive seen a couple of posts on here addressing this topic but somehow I can't make it work completely the only thing im having trouble with is getting rid of the title text in the widget cause when i do this it also removes the picture im trying to add to the title text this is what i have so far


div.widget-title h3 {
display:none;
}

div#recent-comments-3 div.widget-title {
background: url(My picture url in here) center left;
}

but nothing shows up

and when i take this off

div.widget-title h3 {
display:none;
}

the text and picture both show up on top of one another how can i take the text off and just leave the picture

appreciate the help thanks in advance

awesome theme by the way