I Just Received A Copy Of An Ultrasound For My

i just received a copy of an ultrasound for my kidneys which revealed "very prominent renal calyces". in earlier imaging they had found what appeared to be medullary sponge kidney. i have a autoimmune disorder-either mixed connective tissue disease or systemic scleraderma. can you please explain what this means, and if my autoimmune disorder is the cause?