Physical Exam Radial pulse Ulnar pulse Capillary refill Allen's test Patient asked to open and clench both fists tightly repeatedly several times Pressure is applied over radial arteries simultaneously to occlude Patient then opens the fingers of both hands rapidly, and examiner compares the color of both. The initial pallor should be replaced quickly by rubor. The test should then be repeated, this time occluding the ulnar arteries Imaging Three-phase bone scan Phase I (2 minutes) shows an extremity arteriogram Phase II (5-10 minutes) shows cellulits and synovial inflammation Phase III (2-3 hours) shows bone images RSD diagnosed with positive phase III that does not correlate with positive Phase I and Phase II Phase IV (24 hours) can differentiate osteomyelitis from adjacent cellulitis Duplex scan is helpful for arterial intimal lesions (true and false aneurysms) Arteriogram remains gold standard for embolic disease downside is it is invasive with risks Ultrasound duplex imaging is becoming more sensitive and specific Segmental limb pressures