 However, imaging is not the preferred method of diagnosis since the method that is currently considered the standard is the isolation of protoscoleces during surgery or after the person's death and the identification of definitive features of "E. oligarthrus" and "E. vogeli" in these isolated protoscoleces.This is the main way that PE is diagnosed, but some current studies show that PCR may identify "E. oligarthrus" and "E. vogeli" in people's tissues.The only drawback of using PCR to diagnose polycystic echinococcosis is that there aren't many genetic sequences that can be used for PCR that are specific only "E. oligarthrus" or "E. vogeli".