Multiple results in regex

Hi.

I have a string that has multiple references to images in it. I want to pull
each reference out using regex. I've gotten to where I can pull the first
instance out, but not ALL of them. I know each image source starts with
'images/'. I have this so far....

<?php
$pattern = '/[\'\"](images\/[a-z0-9\/\-\_\.]+)[\'\"]/i';
preg_match ($pattern, $string, $matches);
?>

// For example, returns...
Array
(
[0] => "images/some/location/some-image.jpg"
[1] => images/some/location/some-image.jpg
)

This pulls the first instance, but none of the others. I think what the
issue is... is that I am stopping after I get the first one, but I don't
know how to grab the rest. Please help!!

Thanks in advance,
~Philip