Fig. 2. (A –I ) Cross-sectional images from the proximal right arm of patient no. 11 showing complete spread of 1% lidocaine with 5 μg/ml epinephrine. Scans were taken before the first dose; after each of the four local anesthetic injections (10 min apart); 10, 20, and 30 min after the last dose; and once postoperatively (134 min after the last dose). In (A ) and (H ), a 20-mm diameter circle with center in the midaxis of the artery was drawn, showing the four quadrants (Q¹, Q², Q³, Q⁴). The first dose (1 ml) contacted the artery in Q²and Q³. After the last dose, all quadrants were completely filled. Thirty minutes after the last dose, the patient had anesthesia of all main terminal nerves except for the axillary nerve, as at the time of the postoperative scan. She underwent surgery for a trigger finger (thumb) without pain.