Which of the following statement(s) is/are true concerning the diagnosis of a peripheral vascular injury?

d. Both the sensitivity and specificity of arteriography of the injured extremity approaches 100%

Segmental arterial pressure determination by Doppler technique is a valuable adjunct to the physical examination of extremity vascular trauma. The presence of audible Doppler signals over an artery in the extremity does not rule out an arterial injury or indicate adequate perfusion. In the healthy and normovolemic person, the normal ankle-brachial index is 1:1. A ratio less than 0.9 or a 20-mm Hg difference between extremities should arouse the suspicion of significant arterial trauma. Doppler examination has not been widely used to screen for significant venous injuries and is of unproven value. The selective use of arteriography is fundamental to the evaluation of patients with suspected vascular trauma. The indications for arteriography generally have included a history of moderate hemorrhage at the penetrating injury site, injury in proximity to major arterial structures, diminished pulses, and peripheral nerve injury in the distribution of a nerve that is in proximity to a major vessel. Proximity as the sole indication for arteriography in the absence of diminished ankle-brachial ratio or other signs of major trauma, has proven to be an unreliable indicator of the need for arteriography. In the absence of classical signs of major vascular injury, patients with penetrating wounds in proximity to major vessels may be observed closely without arteriography. The use of arteriography can significantly reduce the rate of unnecessary exploration for suspected vascular trauma. If routine surgical exploration is performed whenever vascular injury is suspected, a negative exploration rate of about 60% or more can be expected. Selective use of arteriography reduces the negative exploration rate to about 35%. Arteriography is an extremely reliable method of excluding vascular trauma. In this context, the sensitivity is 97% to 100% and the specificity is 90% to 98%, with an overall accuracy between 92% and 98%.