An abnormal penile/brachial index is defined as which value, indicating vasculogenic impotence?

• A. <0.50 vasculogenic impotence
• B. >0.75 vasculogenic impotence
• C. 0.65-0.74 vasculogenic impotence
• D. <0.65 vasculogenic impotence

Answer: (D)

The penile/brachial index is the ratio of penile systolic pressure to brachial systolic pressure, used to assess arterial inflow to the penis. A normal value is typically above about 0.75, reflecting adequate penile arterial inflow relative to systemic pressure. An abnormal value defined as below 0.65 indicates significant arterial insufficiency, which matches vasculogenic impotence caused by penile arterial disease. Values between 0.65 and 0.74 are often considered borderline, and values well below 0.65 point to more definite vasculopathy. Therefore, a value below 0.65 best indicates vasculogenic impotence.