使用PHP DOM的removeChild不起作用

I have the following code:

我有以下代码:

$doc = new DOMDocument();
$doc->loadHTML($quiz['value']);
$imageElement = $doc->getElementsByTagName('img')->item(0);
}
if(is_object($imageElement)){ 
    $image = $imageElement->getAttribute('src');
    $imageElement->parentNode->removeChild($imageElement); 
}else{ 
    $image = '#'; 
}
$quiz['value'] = $doc->saveHTML();
$doc = n