Knee cap not moving correctly and getting dislodge causing pain? My doctor thinks this is the cause of my knee pain after clear CT arthrogram? Heading for x rays

Good luck. Lots of possible causes but good exam with imaging usually is accurate 95 % of the time.
Tracking Proble, It sounds like your knee cap is having issues with the tracking in the femur groove. This is not an uncommon issue. X-rays with "sunrise" view lend a great deal of information. Physical therapy, and lateral knee bracing can be very effective in treatment. Occassionally surgery is indicated to correct the alignment issues. Good luck.
Sounds likely. Usually ct arthrogram follows the xrays? If the patella is dislocating you need bracing and pt and possible surgery.