Botulinum toxin injection is a safe and effective procedure, with outcomes improved if selection and targeting of intended muscles is precisely executed. Individual differences in patient anatomy, and in muscle location or size, render the standard landmark-based, blind approach less effective. Also, adjacent structures such as blood vessels, nerves, the lung, or the thyroid gland, may be injured when hit by the cannula. Therefore, image-based guidance is recommended.
Ultrasound is a very safe imaging modality and is superior in image quality and more flexible during the procedure compared to other modalities (fluoroscopy, CT and MRI). Finally, the costs of acquisition and maintenance of a clinical ultrasound system are moderate, compared to other imaging modalities.
In this chapter, we performed selective ultrasound-guided injections using cadaver specimens to illustrate the muscles relevant in the treatment of cervical dystonia. With ultrasound, we advanced the needle using the in-plane technique to the center of each muscle, and performed a selective intramuscular injection using dilute India ink. The specific muscle was then exposed in a standard dissection and the extent of the staining was photo documented. In the last section we present panoramic still images of neck regions with a difficult muscle topology.