聚合酶链式反应
Polymerase chain reaction (PCR) is another way to diagnose cryptosporidiosis. It can even identify the specific species of "Cryptosporidium". If the patient is thought to have biliary cryptosporidiosis, then an appropriate diagnostic technique is ultrasonography. If that returns normal results, the next step would be to perform endoscopic retrograde cholangiopancreatography.