Computed tomography in measuring electrode insertion angle and depth for cricopharyngeal muscle electromyography

Haoyue Wu; Ruiping Wang; Lequn Zhu; Yilei Chen; Ye Wang; Austin J Scholp; Zhiyi Zhang; Baitao Zhang; Ping Wan

doi:10.21037/qims-22-1388

Computed tomography in measuring electrode insertion angle and depth for cricopharyngeal muscle electromyography

Quant Imaging Med Surg. 2023 Sep 1;13(9):5568-5578. doi: 10.21037/qims-22-1388. Epub 2023 Aug 15.

Authors

Haoyue Wu^#^{1

2}, Ruiping Wang^#³, Lequn Zhu^#⁴, Yilei Chen⁵, Ye Wang⁶, Austin J Scholp⁷, Zhiyi Zhang⁸, Baitao Zhang⁹, Ping Wan¹

Affiliations

¹ School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine (TCM), Shanghai, China.
² Department of Rehabilitation, Zhejiang Provincial People's Hospital, Hangzhou, China.
³ Clinical Research Center, Shanghai Skin Diseases Hospital, Tongji University, Shanghai, China.
⁴ Department of Radiology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of TCM, Shanghai, China.
⁵ Department of Radiology, Shuguang Hospital, Shanghai University of TCM, Shanghai, China.
⁶ Departmrnt of Neurology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of TCM, Shanghai, China.
⁷ Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
⁸ Department of Rehabilitation, Shuguang Hospital, Shanghai University of TCM, Shanghai, China.
⁹ Department of Otolaryngology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of TCM, Shanghai, China.

^# Contributed equally.

Abstract

Background: Electromyography of the cricopharyngeal muscle (CP-EMG) is one of many assessment tools for dysphagia. The key to performing EMG and BTX injections is to precisely locate the cricopharyngeal muscle with an electrode. One of the main difficulties of electrode insertion is the fact that the CP muscle is located deep within the neck. Since a neck computed tomography (CT) can clearly display the CP muscle, thyroid, and blood vessels in the neck, we speculate that a safe concentric needle electrode insertion path to the cricopharyngeal muscle can be simulated with the assistance of the patient's neck CT which clearly marks the angle and depth of concentric needle electrode insertion. The purpose of this study was to explore simulated electrode insertion angles and insertion depths for cricopharyngeal electromyography based on retrospective CT data and present a method of percutaneous localization of the cricopharyngeal muscle based on CT images of the neck.

Methods: One hundred and forty-three neck CT scans performed between January 2019 and November 2020 were included in this study. With the assistance of the angle and straight-line tools found in the Advantage Workstation 4.4 (GE, HealthCare), simulated insertion angles and depths from the anterior border of the sternocleidomastoid muscle to the cricopharyngeal muscle were obtained.

Results: The 143 CT images originated from participants that included 63 males (44.1%) with an average age of 46.2±13.9 years old. The insertion angle, insertion depth, and neck thickness measured on the CT images were 53.2±10.7˚, 24.2±4.1 mm, and 130.1±17.7 mm, respectively. The insertion angle and depth were significantly greater in males than in females (P<0.05), and the insertion angle increased with the age of participants (P<0.05). A generalized linear model (GLM) showed that insertion angle was positively correlated with neck thickness (β=0.14; 95% CI: 0.03 to 0.25) and gender (β=5.08; 95% CI: 1.31 to 8.85), and negatively correlated with age (β=-5.88; 95% CI: -9.54 to -1.62). Insertion depth was only positively correlated with the neck thickness (β=0.11; 95% CI: 0.07 to 0.15).

Conclusions: This study indicates that age, gender, and neck thickness are influencing factors for insertion angle, while neck thickness is the influencing factor for insertion depth. The simulated concentric needle electrode insertion method based on CT can assist clinical operation to ensure safety and effectiveness of cricopharyngeal electromyography.

Keywords: Cricopharyngeal muscle; computed tomography (CT); electromyography.