phpMyAdmin - Find and replace - edit image url

[okanner48]

I have very old image url like this: http://lh3.ggpht.com/-Ep5ZsFwjOfk/T1fePeYuPNI/AAAAAAAAPHg/Kwq3XqDyWl4/7865673.jpg?imgmax=1800

On phpMyAdmin I've used "find and replace code" UPDATE wp_posts SET post_content = REPLACE ( post_content, 'jpg?imgmax=1800', 'jpg');

After updating image url has changed like this: http://lh3.ggpht.com/-Ep5ZsFwjOfk/T1fePeYuPNI/AAAAAAAAPHg/Kwq3XqDyWl4/7865673.jpg

But I want to write before image name s1600/

Sample link: http://lh3.ggpht.com/-Ep5ZsFwjOfk/T1fePeYuPNI/AAAAAAAAPHg/Kwq3XqDyWl4/s1600/7865673.jpg

Can I change that via find and replace code or...

Thanks in advance.