Learning objectives
To review high-resolution ultrasound imaging of peripheral nerves with emphasis on small peripheral nerve branches.
Background
With recent advancements in imaging technology including the development of clinical 24 MHz/33 MHz probes,
high-resolution ultrasonography has emerged as an excellent tool for imaging of peripheral nerves.
Sonographic evaluation of superficial peripheral nerves is best performed with high-frequency probe (18 MHz and 24 MHz probes are used at our institution) whereas evaluation of deeper peripheral nerves may require a relatively lower frequency probe (ie.
14 MHz).
Ultrasound can also be used for image guidance for perineural steroid injections.
Advantages of ultrasound include that it...
Imaging findings OR Procedure Details
Knowledge of basic nerve anatomy is important for accurate interpretation of nerve imaging. Individual nerve fibers are encircled by the endoneurium,
and a group of nerve fibers are encircled by the perineurium to form a fascicle.
A group of fascicles is in turn encircled by the epineurium,
which represents the outermost layer of a nerve.
Interspersed between the fasciculi are blood vessels which run longitudinally within the nerve.
Nerve anatomy can be identified on high resolution ultrasound up to the fascicular level (Figures 1,2,3,4). In...
Conclusion
High-resolution ultrasonography is an excellentmodality for imaging evaluation of peripheral nerves including small peripheral nerve branches.
Ultrasound can readily detect pathology of peripheral nerves including neuritis,
nerve entrapment,
extrinsic compression,
nerve sheath tumors,
and traumatic laceration.Given the fact thatultrasoundis operator-dependent,
an intimate knowledge of peripheral nerve anatomy and the spectrum ofimaging findings is crucial. In an experienced musculoskeletal radiologist’s hands,
ultrasound is apowerful tool for patients with peripheral nerve pathology.
References
1) Zaidman CM,Seelig MJ,Baker JC,Mackinnon SE,Pestronk A.Detection of peripheral nerve pathology: comparison of ultrasound and MRI.Neurology 2013;80(18):1634–1640.
2) Jacobson,
J.A.,
Wilson,
T.J.,
and Yang,
L.J.-S.
(2016).
Sonography of Common Peripheral Nerve Disorders With Clinical Correlation.
J Ultrasound Med 35,
683–693.
3) Brown,
J.M.,
Yablon,
C.M.,
Morag,
Y.,
Brandon,
C.J.,
and Jacobson,
J.A.
(2016).
US of the Peripheral Nerves of the Upper Extremity: A Landmark Approach.
RadioGraphics 36,
452–463.
4) Cartwright,
M.S.,
Chloros,
G.D.,
Walker,
F.O.,
Wiesler,
E.R.,
and Campbell,
W.W.
(2007).
Diagnostic ultrasound for nerve...
Personal Information
Swati Deshmukh,
MD
Assistant Professor
Department of Radiology
Division of Musculoskeletal Imaging
Northwestern University
Northwestern Medical Group
Northwestern Medicine Spine Center
676 N.
Saint Clair Street,
Suite 800
Chicago,
Illinois 60611