My mother, age 66, had a hida score/result of 21. what does this mean?

Biliary colic ?: 20% ejection fraction after injection of cholecystokinin (cck) is low. Normal is usually above 33-35%. If test was performed correctly with slow injection of cck results indicate either chronic gb disease or gb dyskinesia.Hida quite accurate when patient has symptoms of biliary colic. Sometimes symptoms typical pain during test. Ultrasound of gb usually done to rule out stones/sludge.