Stephan Kapral from Vienna was the first who presented an US guided nerve block with real-time visualisation of the target nerves and the perineural spread of local anaesthetic
It was a supraclavicular brachial plexus block
Kapral S, Kraff P, Eibenberger K, Fitzgerald R, Gosh M, Weinstabl C: Ultrasound-guided supraclavicular approach for regional anesthesia of the brachial plexus. Anesthesia & Analgesia, 78:507-513 (1994)
The figure is from Kapral’s pioneer paper in 1994. It demonstrates how much sonographic image quality has improved from 1994 until today.
