My friends over at Nomad the makers of the hand held x-ray device have introduced a rectangular collimation device. It is a simple aperture system that attaches to the Nomad cone. The benfit is reduced scatter radiation and improved image quality.
Even though it is better, users were reluctant to use rectangular collimation with old fashioned wall mounted systems because the narrower beam just seemed too likely to miss the target. However with the hand held Nomad it is easy to line up quickly accurately and then just hold it still and pull the trigger. Easy peasy.