Which range defines a marginal penile/brachial index?

• A. 0.75 or greater
• B. 0.65-0.74
• C. <0.65
• D. 0.80-0.89

Answer: (B)

The key idea is that the penile-brachial index compares penile arterial inflow to systemic arterial pressure to assess vascular contribution to erections. A normal index means the penile blood flow is adequate. When the value is just short of that normal cutoff, it’s considered marginal—this is the grey zone where flow is reduced enough to suggest possible early penile arterial disease but not yet severely compromised. It signals a vascular issue that may warrant further evaluation or management of risk factors. Values well below the normal threshold indicate definite arterial insufficiency, while values well above are normal. So the marginal range is the interval just below the normal threshold, indicating borderline penile arterial inflow.