The Axillary Region in a High Resolution MRI
Condition: MRI Scanner Configuration
Study type: Interventional
Phase: Phase 2

Summary: 
      The axillary region is regularly used for brachial plexus block. The technique may be guided
      by nerve stimulation, ultrasound or a combination of nerve stimulation and ultrasound.
      Magnetic resonance imaging (MRI) has been beneficial in presenting anatomy of interest for
      regional anesthesia and in demonstrating spread of local anesthetic (LA). An axillary
      MRI-study at our department supported the suggestion of multiple rather than a single
      injection technique. Using a 0.5 Tesla open MR scanner in that study, the investigators were
      not able to distinguish terminal nerves from equally sized vessels. Therefore the
      investigators could not definitely answer whether the LA reached the pertinent nerves. The
      investigators have recently performed an axillary block study with a 3.0 Tesla scanner. Now
      the terminal nerves were identified and for each patient the investigators could observe if
      the LA reached the nerves.

      The aim of this study was to demonstrate the anatomy of the brachial plexus in the axillary
      region at different levels. The investigators present the best pictures of the nerves with
      and without LA injected. The images are demonstrated in the axial and coronal plane.
    

Detailed description: 
      For upper limb surgery, the brachial plexus can be blocked at the interscalene,
      supraclavicular, infraclavicular and axillary level as an alternative to general anesthesia.
      The axillary block requires more deposits to achieve a complete block. MRI investigations are
      of interest to better understand the block specific distribution of LA. With the new MRI
      Achieva 3.0T X-series (Philips Electronics, Eindhoven the Netherlands), with resolutions
      beyond 100μm using 2k imaging, we expected new information also compared with the earlier
      axillary MRI publication from our department. In that former study we used a single deposit
      technique in an open 0.5 Tesla scanner. We could not in that study recognize the terminal
      nerves or determine if the LA reached the axillary plexus.

      MRI publications of the brachial plexus mostly study the shoulder region and few are
      describing the axillary region. We did not find any article describing the axillary brachial
      plexus using a 3.0 Tesla high resolution MRI.

      Ultrasound visualizes the plexus nerves in the axilla and demonstrates dynamically the spread
      of LA. This usually occurs in 2-dimensional images where the initially observed LA fades
      after some minutes. MRI provides more easy 3 - dimensional images also in oblique planes
      compared with ultrasound.

      This study was done in order to demonstrate the relevant anatomy in the volunteers and the
      spread of LA in patients. We also present the used protocols and MRI - stacks after having
      optimized the configuration of the 3.0 MRI scanner.
    

Intervention name(s): MRI
Intervention type(s): Radiation
Intervention description(s): High resolution MRI of the brachial plexus
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Magnetic Resonance Imaging; Nerve Net; Brachial Plexus; Nerve block