1. Ultrasound standard for lumbar plexus block
J.-A. Lin, H.-T. Lu, T.-L. Chen 
British Journal of Anaesthesia 
Volume 113, Issue 1, Pages (July 2014)
DOI: /bja/aeu213
Copyright © 2014 The Author(s) Terms and Conditions

2. Fig 1
The transducer position relative to the needle shaft. The ultrasound beam is directed towards the simulated trajectory line vertical to the patient skin (yellow dotted line). After needle insertion for a short distance, the actual needle trajectory could be found by slightly tilting the transducer. The blue star shows sometimes part of the transducer needs to be slightly off the skin but with the ultrasound beam perpendicular to the needle shaft (yellow dotted arrow) to obtain the complete shamrock view with the transverse process centred in the ultrasound screen.
British Journal of Anaesthesia  , DOI: ( /bja/aeu213)
Copyright © 2014 The Author(s) Terms and Conditions