MRI Scanner Configuration Clinical Trial
Official title:
The Axillary Region in a High Resolution MRI. Imaging Before and After Brachial Plexus Block
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.
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.
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Allocation: Non-Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Basic Science