Update to BinaryMoon's MS solution for timthumb image URLS

function get_image_path ($post_id = null) {
    if ($post_id == null) {
        global $post;
        $post_id = $post->ID;
    }
    $theImageSrc = get_post_meta($post_id, 'Image', true);
    if ( is_multisite() && $blog_id > 0) {
        $imageParts = explode('/blogs.dir/', $theImageSrc );
        if (isset($imageParts[1])) {
            $theImageSrc = network_site_url('/wp-content/blogs.dir/' . $imageParts[1]);
        }
    }
    return $theImageSrc;
}