Figure 15. Normal resistive index measurement. Duplex color Doppler flow imaging is useful in assessing the intraparenchymal arterial pressures as an indirect measure to detect complications such as vascular thrombosis, acute graft rejection, and pancreatitis. The measurement can be obtained from the intraparenchymal arterial vasculature (head, body, tail), or the extraparenchymal arterial vasculature (Y-graft). However, these measurements have not proved to be sensitive or specific in diagnosing certain complications.