A 65-year-old retired firefighter complains of calf pain when walking more than a few hundred feet. He states that the pain typically will go away once he sits down to rest, but will start again after walking another few hundred feet. He has a history of type II diabetes which is fairly well controlled with metformin. He had a 20-pack-year smoking history before he quit approximately five years ago. What would be the test of choice to initially evaluate this patient? Lower extremity angiogram. Magnetic resonance imaging (MRI) angiogram of the lower extremities. Duplex ultrasound of the lower extremities. Ankle-brachial index (ABI). Plain film X-ray of tibia and fibula.