Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Sep 7:4:2000206.
doi: 10.1109/JTEHM.2016.2581811. eCollection 2016.

Image-Guided High Intensity Focused Ultrasound System for Large Animal Nerve Ablation Studies

Arthur Worthington  1 , Philip Peng  2 , Kevin Rod  3   4 , Vera Bril  5 , Jahan Tavakkoli  6   7
Affiliations

Image-Guided High Intensity Focused Ultrasound System for Large Animal Nerve Ablation Studies

Arthur Worthington et al. IEEE J Transl Eng Health Med. .

Abstract

High intensity focused ultrasound (HIFU) is a form of thermal ablation technique, which can treat a variety of medical afflictions. One promising therapeutic use is the permanent destruction of nerves non-invasively in patients with severe spasticity or certain types of pain (e.g., phantom limb pain). To this end, HIFU requires ultrasound guidance, which allows the non-invasive, target-specific deposition of thermal energy to the targeted nerve, thereby blocking axonal conduction. In this paper, a composite system comprising both ultrasound-imaging and HIFU therapy was developed and used to induce localized non-invasive nerve blockage in an in vivo large animal study. Five pigs were used with the femoral nerve as the target. Calibrated needle thermocouples inserted at the target site were employed to monitor the target tissue temperature. The degree of nerve blockage was assessed by measuring compound action potential (CAP) signal with a clinical nerve electrophysiology system before and after HIFU exposures. An average CAP signal amplitude reduction of 49% of baseline with a standard deviation of 9% was observed after 20-30 min post exposure. These results demonstrate the feasibility of the proposed ultrasound-guided HIFU modality as a potential non-invasive nerve ablation method.

Keywords: CAP measurement; non-invasive nerve ablation; porcine femoral nerve; ultrasound-guided HIFU.

PubMed Disclaimer

Figures

FIGURE 1.
FIGURE 1.
Portable HIFU transducer; OD = 65 mm; ID = 26 mm; Focal length = 66 mm; F# = 1.02. The HIFU transducer is the grey donut with the imaging probe in the middle.
FIGURE 2.
FIGURE 2.
Block diagram of the experimental setup for the porcine nerve blocking study.
FIGURE 3.
FIGURE 3.
Experimental setup during the procedure in the operating room. The pig is on the operating table with the CAP probe against its thigh.
FIGURE 4.
FIGURE 4.
Needle thermocouple (straight line in ellipse) implanted next to the femoral nerve (circle) in the right thigh of the pig.
FIGURE 5.
FIGURE 5.
Electrophysiology probe stimulating the porcine nerve and recording conduction pre and post exposure.
FIGURE 6.
FIGURE 6.
Typical measured temperature of the ROI during a HIFU exposure sequence.
FIGURE 7.
FIGURE 7.
Ultrasound B-Mode image of a typical thermal lesion post HIFU exposure. The lesion is visible as a hyperechoic region which coincides with the location of the HIFU focal point in the ROI (ellipse).
FIGURE 8.
FIGURE 8.
Typical femoral nerve CAP measurement display.
FIGURE 9.
FIGURE 9.
Excised tissue showing the formula image mm thermal lesion created.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Tavakkoli J. and Sanghvi N. T., “Ultrasound-guided HIFU and thermal ablation,” in Therapeutic Ultrasound: Mechanisms to Applications,” V. Frenkel, Ed. Nova Science Publishers, 2011, pp. 137–167.
    1. Foley J. L. and James W. L., and Vaezy S., “Effects of high-intensity focused ultrasound on nerve conduction,” Muscle Nerve, vol. 37, no. , pp. 241–250, Feb. 2008. - PubMed
    1. Cohen S. P., Hurley R. W., Christo P. J., Winkley J., Mohiuddin M. M., and Stojanovic M. P., “Clinical predictors of success and failure for lumbar facet radiofrequency denervation,” Clin J Pain vol. 23, no. 1, pp. 45–52, Jan. 2007. - PubMed
    1. Cohen S. P., et al. , “Outcome predictors for sacroiliac joint (lateral branch) radiofrequency denervation,” Regional Anesthesia Pain Med., vol. 34, no. 3, pp. 206–214, May-Jun 2009. - PubMed
    1. Choi W. J., et al. , “Radiofrequency treatment relieves chronic knee osteoarthritis pain: A double-blind randomized controlled trial,” Pain, vol. 152, no. 3, pp. 481–487, Mar. 2011. - PubMed

Grants and funding

The work of J. Tavakkoli was supported by the Ontario Research Fund–Research Excellence Grant.