Spatial mapping of the brachial plexus using three-dimensional ultrasound

Area of Science:

• Medical Imaging
• Anatomy
• Regional Anesthesia

Background:

• Two-dimensional (2D) ultrasound and MRI can image the brachial plexus.
• Ultrasound-guided regional anesthetic blocks are established techniques.
• Understanding brachial plexus anatomy is crucial for regional anesthesia.

Purpose of the Study:

• To map brachial plexus orientation using three-dimensional (3D) ultrasound.
• To assess the relationship between the brachial plexus, first rib, and arteries.
• To identify anatomical variations relevant to regional anesthesia.

Main Methods:

• Utilized a free-hand optically tracked 3D ultrasound system with a 12 MHz transducer.
• Performed 3D ultrasound on 10 healthy volunteers.
• Manually segmented brachial plexus, subclavian artery, and first rib outlines from 3D datasets for reconstruction.

Main Results:

• Successfully mapped the brachial plexus in all volunteers, with variable image resolution.
• Demonstrated anatomical variations in plexus division alignment among volunteers.
• 3D reconstructions showed a shift in plexus orientation from vertical (interscalene) to horizontal (supraclavicular fossa).

Conclusions:

• 3D ultrasound enables spatial mapping of the brachial plexus using the subclavian artery and first rib as landmarks.
• Observed deviations from conventionally described brachial plexus anatomy.
• Findings may have implications for the precise administration of regional anesthesia.