Calcium pyrophosphate dihydrate crystals are associated with a range of clinical syndromes, which have been given various names, based which clinical symptoms or radiographic findings are most prominent.
It can be associated with hemorrhagic nodules, tumors, or inflammatory processes, but is most commonly known as an early radiographic sign of invasive pulmonary infection by the fungus species Aspergillus.
It is commonly used in radiographic studies such as intravenous urograms, brain computer tomography (CT) and CT pulmonary angiograms (CTPAs).