Caliectasis occurs when there is excess fluid in your calyces (cavities in which urine collects before it flows into the urinary bladder). Causes of caliectasis include blockage/obstruction in the kidneys, cysts, tumors, kidney stones, urine buildup (hydronephrosis), and urinary tract infections. Based on your MRI images, this finding is nonspecific, meaning it is difficult to say what caused it.