Yes, the LAX view is still my most useful although I do look in both planes.
Injecting small amounts of saline or lignocaine into areas of concern in the rotator cuff is something that many people do as a diagnostic test and it works very well.
You can also add a little gas to the injection by adgitating the liquid prior to injecting and use the gas bubbles as contrast.
This is a well established technique.
One word of caution is that there are some areas where natural clevage planes exist such as in the area between the rotator cuff interval and the very anterior fibres of SST and injecting these areas can sometimes create a plane that looks like a tear but may be anatomical.
By all means if you see an area in the SST that looks like a possible tear and you can not be satisfied with conventional imaging in relaxed, modified crass and full crass positions a logical next step is to challenge it with an injection while you watch.
My great friend Dr Ray Chen in Taichung uses this technique regularly as does Dr Wesley Chen in Taipei.
Steve