A 47 year old woman presents to her physician complaining of sudden pain of her left hand associated with numbness for three hours. She has a long history of palpitations but she had never asked for medical advice. Her past medical, surgical and family histories are unremarkable. On examination, her pulse is 98 and irregularly irregular. Her left hand is cold and clammy. Doppler ultrasound shows absent blood flow in brachial, ulnar and radial arteries. A CT arteriogram is performed on her left subclavian artery. What is the most likely finding on this patient's CT arteriogram? A- Massive arteriosclerotic changes of the artery B- Impacted embolus at the bifurcation of the artery C- Narrowing of the lumen due to compression from outside D- Normal arteries and normal blood flow Answer: http://medical-usmle.com/?p=1228