New Paradigms for Ultrasound: Assessing Peripheral Nerves

NEW PARADIGMS FOR ULTRASOUND: ASSESSING PERIPHERAL NERVES

Pegasus Lectures’ President Frank Miele invited me to guest-blog a recap of my presentation at the  2019 American Institute of Ultrasound in Medicine (AIUM) Annual Convention.  The topic was The Role of Ultrasound in Locating and Assessing Peripheral Nerves, and this discussion harmonizes well with Frank’s previous posts on ‘New Paradigms for Ultrasound’.

As Frank has emphasized, there are advances in ultrasound technology that will open entire new fields of specialization for sonographers and ultrasound professionals who wish to expand their skillsets and earning potential.

While many of the technologies Frank discussed are five to ten years away from materializing, the specialty I will review is opening up in the here and now.  These are applications of ultrasound technology in the field of musculoskeletal evaluation, and more specifically diagnosing pathologies of peripheral nerve structures.

Long  Axis  View  of  the  Ulnar  Nerve  in  the  Cubital  Tunnel

Newer applications in ultrasound technology were made possible by the development of lower-cost high-frequency (20+ MHz) transducers over the past 10 years.  Channeling Ultrasound Physics & Instrumentation author, Frank Miele…recall from the Wavelength Equation that frequency and wavelength are inversely proportional.  So with higher frequency comes shorter wavelength, producing a more precisely targeted and focused beam, and therefore superior spatial resolution.

High-frequency transducers are now widely available, and with the introduction of truly portable models that plug into your smartphone or tablet computer, ultrasound evaluations now offer a favorable alternative to the more-traditional imaging modality of magnetic resonance imaging (MRI).

Without disrespecting the technology and diagnostic capabilities of MRI, here are a few real-world considerations that weigh favorably toward the emergence of ultrasound modalities for neurological studies:

COST/AVAILABILITY – Ranging in price from $250,000 to $1,000,000+, MRIs are simply not economical for most non-hospital facilities.  In the United States, nearly one half of the approximately 13,000 MRIs are located within hospitals.  While the United States has the most units of any country in the world, there are still only 40 MRI units for every 1 million residents. Its cost as a capital goods asset requires a commensurate exam cost to offset the expense of ownership and operation.  Additionally, the relative scarcity of the equipment does not work favorably in terms of price competition.

PATIENT CARE/INTERACTION – I doubt many people will dispute that patients generally dislike the MRI examination experience.  It’s a fact of life.  Ultrasound studies, by contrast, offer results in real-time, and allow technician/patient interaction that is superior to any comparable MRI study.  Again, with no disrespect, a running MRI unit emits sound waves approaching 90-100 decibels (db), which is roughly equivalent to a power lawn mower, or motorcycle….not exactly a comforting and collaborative atmosphere for sonographer to patient interaction.

In two weeks, I will follow up with a specific discussion on best practices for conducting a successful nerve imaging study.

Jamie Bie is the Senior Musculoskeletal Ultrasound Specialist at Columbia University/New York Presbyterian Imaging. She was awarded the ARDMS Pioneer Musculoskeletal Ultrasound credential in 2012. In addition to holding the RMSKS credential, she is also registered in Vascular Technology, Abdomen, OB/GYN, and Breast. Jamie has written departmental protocols and has trained several physicians and sonographers in Musculoskeletal Ultrasound.

Jamie Bie is also the author of newly-released Musculoskeletal Ultrasound: A Comprehensive Guide to MSK Imaging and Interventional Techniques, a comprehensive, step-by-step guide to MSK Ultrasound. This textbook includes an overview of MSK Ultrasound physics, illustrated protocols, anatomy review by section, transducer and ultrasound overlays to clarify positioning and structure recognition, and CheckPoints noted throughout the text, providing critical technical tips.