Figure 37-4

Figure 37-4. Duplex ultrasonography and Doppler analysis of the arterial response to intracavernous papaverine injection. In the flaccid state (A), the luminal diameter of the cavernous artery is 0.06 cm; after papaverine injection (B), this increases to 0.13 cm. Wave analysis (C) shows normal flow in the cavernous artery (peak velocity, 39 cm/s).