使用PHP从Google自定义搜索rss中获取价值

Question

I have a Google Custom search RSS that gives me this xml (simplified):

<?xml version="1.0" encoding="UTF-8"?>

 <title>Google Custom Search - the rocky horror picture show 1975</title>

 <entry gd:kind="customsearch#result">
   <id>http://www.imdb.com/title/tt0073629/</id>
   <cse:PageMap>
     <cse:DataObject type="metatags">
       <cse:Attribute name="og:image" value="http://URLtoAnImage.com/image.jpg"/>
<!-- and so on... -->

I managed to get the value of "id" (http://www.imdb.com/title/tt0073629/) into an array ($item) with this php:

$rss = new DOMDocument();
$rss->load($myRSS); // the RSS URL

$feed = array();

foreach ($rss->getElementsByTagName('entry') as $node) {
    $item = array ( 
       'link' => $node->getElementsByTagName('id')->item(0)->nodeValue,
        );
    array_push($feed, $item);
    break; //break because I only want the first search result (entry)
}

Can someone please help me get the "og:image" value into the same array with the same php code?

Or do I need a different php code?