Searching 2 tables based on keyword, but also pull in image on search results

I am trying to pull information from 2 tables based on a search keyword, this much I have achieved. But the results also have an associated thumbnail image which I want to also pull in. How can I achieve this. I am guessing it would require modifications to the /cms/lib/viewer_functions.php file but I am stuck as how to achieve this. Heres the working code that pulls the right result (but without any images).

in the products table the image field is called "image_gallery', i need to display the first thumbnail image

in the case_studies table the image field is called "images", again i need to display the first thumbnail image

 <!-- search form-->

<form id="search" action="/search.php" method="get">
<div id="label"><label for="search-terms" id="search-label">search</label></div>
<div id="input"><input type="text" name="q" id="search-terms" placeholder="Enter search terms..." value="<?php echo htmlspecialchars(@$FORM['q']); ?>"></div>
</form>


 <!-- search script-->
<?php 
/*  search tables */  
       $searchOptions = array();
      $searchOptions['keywords'] = @$FORM['q'];
      $searchOptions['perPage']  = "10";
      $searchOptions['debugSql'] = "1";

      $searchTables = array();
      $searchTables['products'] = array(
        'viewerUrl'       => 'products.php',
        'titleField'      => 'title',
        'summaryField'    => 'product_details',
        'searchFields'    =>  array('title','product_details'),
      );

      $searchTables['case_studies'] = array(
        'viewerUrl'       => 'case-study.php',
        'titleField'      => 'title',
        'summaryField'    => 'details',
        'searchFields'    =>  array('client','title','details'),
      );
      list($searchRows, $searchDetails) = searchMultipleTables($searchTables, $searchOptions);
 
/*  limit number of characters from summary field */     
function custom_echo($x){
  if(strlen($x)<=240) { echo $x; } else { $y=substr($x,0,240) . ' ...'; echo $y; }
}

?>

 <!-- search results-->
  <?php foreach ($searchRows as $record): ?>
  <!-- trim code from end of _link and replace with custom code -->
     <h1><a href="<?php $link=$record['_link']; $new_link= rtrim($link, '?1234567890'); echo $new_link; ?>?num=<?php echo $record['num'] ?>"><?php echo $record['_title'] ?></a></h1>
     <?php if ($record['_summary']): ?>
       <p><?php echo custom_echo($record['_summary']); ?></p>
      <?php endif ?>
    <p><a href="<?php $link=$record['_link']; $new_link= rtrim($link, '?1234567890'); echo $new_link; ?>?num=<?php echo $record['num'] ?>"><?php $link=$record['_link']; $new_link= rtrim($link, '?1234567890'); echo $new_link; ?>?num=<?php echo $record['num'] ?></a></p>
      </p>
<?php endforeach ?>

  <!-- paging -->
  <?php if (($searchOptions['keywords'] !== "")OR(!$searchOptions['keywords'] && !$searchDetails['noRecordsFound'])) : ?>
<p>
    <?php if ($searchDetails['prevPage']): ?>
      <a href="<?php echo $searchDetails['prevPageLink'] ?>">&lt;&lt; Previous</a>
    - page <?php echo $searchDetails['page'] ?> of <?php echo $searchDetails['totalPages'] ?> -
    <?php endif ?>
    <?php if ($searchDetails['nextPage']): ?>
      <a href="<?php echo $searchDetails['nextPageLink'] ?>">Next <strong>&gt;&gt;</strong></a>
    <?php endif ?>
</p>
    <?php endif ?>