Determine Cardtype?

I am doing an implementation of Cardinal Commerce verified by visa / mastercard on CS-Cart 4. The customer is running an older version of CS-Cart so I've setup my test system on a LAMP stack.

In reviewing the previous code which lives inside of the authorizenet_aim.php gateway script the previous developer has some code which says:

$_SESSION['CardType'] = $order_info['payment_info']['card'];

This is supposed to be a 3 letter representation of the card type used for the order such as: 'vis', 'mcd', 'din', 'jcb', etc. When examining $order_info in CS-Cart 4 I don't see anything that looks like “card” made the jump from 3.x to 4.x.

Shy of implementing some kind of javascript or hooking into the fn_start_payment() function and determining it myself is there a default way of knowing the card type in CS-Cart 4?