Get a post thumbnail from external blog into a PHP page - php

Question

I'm not knowledgeable in PHP (to set the tone). I found some code to grab an external WP blog rss and display recent posts in my custom PHP page (outside the WP blog). I'm trying to get the post thumbnail, but can't figure it out. Been googling for about 2 hours - figured it was time to as directly. Here's the code that is successfully getting the post title and link:
<?php
$rss = new DOMDocument();
$rss->load('http://website.com/blog/feed/');
$feed = array();
foreach ($rss->getElementsByTagName('item') as $node) {
$item = array (
'title' => $node->getElementsByTagName('title')->item(0)->nodeValue,
'link' => $node->getElementsByTagName('link')->item(0)->nodeValue,
);
array_push($feed, $item);
}
$limit = 5;
for($x=0;$x<$limit;$x++) {
$title = str_replace(' & ', ' & ', $feed[$x]['title']);
$link = $feed[$x]['link'];
echo '<p>'.$title.'<br />';
}
?>
What do I add to get the post thumbnail? This is from my own external WP blog, so I can make changes there if needed, but lost on how to accomplish this.
Thanks in advance
Shawn
Appended - here is the RSS feed code from the blog:
<?php
/**
* RSS 0.92 Feed Template for displaying RSS 0.92 Posts feed.
*
* #package WordPress
*/
header('Content-Type: ' . feed_content_type('rss-http') . '; charset=' . get_option('blog_charset'), true);
$more = 1;
echo '<?xml version="1.0" encoding="'.get_option('blog_charset').'"?'.'>'; ?>
<rss version="0.92">
<channel>
<title><?php bloginfo_rss('name'); wp_title_rss(); ?></title>
<link><?php bloginfo_rss('url') ?></link>
<description><?php bloginfo_rss('description') ?></description>
<media:thumbnail url="thumbs/DSC00385.JPG" width="100" height="100"/>
<lastBuildDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_lastpostmodified('GMT'), false); ?></lastBuildDate>
<docs>http://backend.userland.com/rss092</docs>
<language><?php bloginfo_rss( 'language' ); ?></language>
<?php
/**
* Fires at the end of the RSS Feed Header.
*
* #since 2.0.0
*/
do_action( 'rss_head' );
?>
<?php while (have_posts()) : the_post(); ?>
<item>
<title><?php the_title_rss() ?></title>
<description><![CDATA[<?php the_excerpt_rss() ?>]]></description>
<link><?php the_permalink_rss() ?></link>
<?php
/**
* Fires at the end of each RSS feed item.
*
* #since 2.0.0
*/
do_action( 'rss_item' );
?>
</item>
<?php endwhile; ?>
</channel>
</rss>