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Updated: Feb 16, 2026

Author Spotlight: Ultrasound-Guided Needle Release Combined with Corticosteroid Injection for the Treatment of Supinator Syndrome
Published on: May 26, 2023
Visualization of Needle-Tip Localization by Ultrasound Guidance with Contrast Bubble in Lumbar Selective Nerve Root
Sorayouth Chumnanvej1, Kitipat Kittayapirom1, Siriluk Chumnanvej2
1Neurosurgery Division, Surgery Department, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Background:
Epidural steroid injection for low back and leg pain has been shown to result in a positive clinical outcome. Lumbosacral selective nerve root block (SNRB) via a transforaminal approach is commonly performed under fluoroscopic guidance. However, ultrasound guidance is an alternative to overcome the radiologic disadvantages. This study examined the accuracy of needle-tip localization under ultrasound guidance with a contrast bubble, compared with fluoroscopic guidance.
Objective:
The primary objectives were to envisage the needle-tip localization with an air bubble by ultrasound and also to determine the accuracy of needle-tip location in transforaminal lumbar SNRB for low back and leg pain patients who were not surgical candidates.
Methods:
A prospective study of 30 SNRBs was conducted. An air bubble was produced and was used to envisage the needle-tip location under ultrasound guidance. Finally, the needle tip was confirmed by fluoroscopy. The accuracy of needle-tip location was statistically analyzed.
Results:
Twenty-four SNRBs were performed at L4-5 and 6 SNRBs at L3-4. The accuracy of needle-tip localization was 80%.
Conclusion:
In order to avoid radiation exposure during the SNRB procedure, ultrasound guidance might be an alternative. Despite being accepted practice, there is a steep learning curve involved in the use of ultrasound guidance for lumbar SNRB, and proper training is crucial. A contrast bubble is a prospective enhancement for better visualization of ultrasound guidance.
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