Sludge in GB???

Hello - I am coming over from Kidney Cancer board to ask a question.  I am 33 years old, female and just had a 1/4 of my kidney removed in December.  It was Renal Cell Carcinoma.  Yesterday I had my 3 month post surgery scan and all looked good except my Gall Bladder. They said there is "sludge" in my gallbladder... exact words were "Intrinsic gallbladder T1 hyperintensity is indeterminant and may be secondary to biliary sludge, prior contrast administration, or, less likely, hemorrhage."

Does anyone know what that means?  I asked my Kidney Surgeon and she just said I think blah blah blah but I dont want just a guess, I want a definititive answer.  Should I go see someone else regarding this issue??  Is it cancer?  Could it turn into cancer?  I am just slightly hyper paranoid now b/c I got kidney cancer at such a young age.

Thanks!