Trying to get image thumb manually

I am trying to get image thumbnail manually on tpl.php file...

$uc_thumbnail_image = $result['node']->field_image_cache[0];
$thumbnail = theme('imagecache', 'cart', $uc_thumbnail_image['filepath'], $uc_thumbnail_image['data']['alt'], $uc_thumbnail_image['data']['title']);

but this does not work the file path after 'cart' is blank...am I missing something, I really really appreciate some help