Not a few of you have heard this word and wondered what it meant for your health and management. Here is what it means. On the one hand, crystal deposits in kidney tissue. On the other, the name radiologists use when they see calcified regions overlying your kidneys, regions that are not clearly free stones but could be stones or tissue mineral. They really cannot tell with great precision. They never could. Modern high resolution ureteroscopy can tell, and surgeons everywhere have adopted this wonderful technology into common practice. You need to know this. Those of you who carry the diagnosis of nephrocalcinosis will all benefit from modern surgical visualization as opposed to indirect means of radiology.