A penile/brachial index below which value is associated with vasculogenic impotence?

• A. 0.75 or greater
• B. 0.65-0.74
• C. <0.65 vasculogenic impotence
• D. 0.50-0.60

Answer: (C)

The test is about how the penile–brachial index reflects penile arterial inflow and its relation to vasculogenic erectile dysfunction. The penile–brachial index compares the systolic pressure in the penis to the systolic pressure in the arm. A normal value is typically above about 0.75, indicating adequate penile arterial inflow. When the index falls below 0.65, penile arterial inflow is significantly reduced, which is consistent with vasculogenic impotence due to arterial insufficiency. Values in the 0.65–0.74 range may show some impairment, but below 0.65 most strongly indicates vascular (vasculogenic) erectile dysfunction. Very low values like 0.50–0.60 suggest more severe arterial compromise, but the critical threshold used to define vasculogenic impotence is below 0.65.