Include image in wp_nav_menu

I am trying to include an image in one of my menus like this, but its just printing out the path. What’s the proper way to do this?

<?php $arrow = “<img src='”. bloginfo(‘template_url’) . “/images/arrow.png’/>”; ?>
<?php wp_nav_menu(array(‘menu’ => ‘main_menu’, ‘container’ => ‘ul’, ‘menu_id’ => ‘main_bar_menu’,
‘before’ => ‘<div id=”arrow”>’.$arrow.'</div>’)); ?>