Background and aims In our institution, transforaminal thoracic nerve block, which used to be performed under fluoroscopy (UF method), is now performed by an ultrasound-guided (US method) approach.

Methods The US method is performed with the patient in the prone position using the parallel technique by a linear probe. First, place a probe parallel to the ribs and then slide it caudally to visualize the transverse processes, internal intercostal membranes, and superior costotransverse ligaments. By sliding the probe more caudally, the transverse processes disappear, and vertebral laminae can be visualized. The inclination of the internal intercostal membrane also increases, and the intervertebral foramen exists between the vertebral lamina and internal intercostal membrane. The thoracic transforaminal epidural injection is completed by injecting a drug solution at the site where the intervertebral foramen crosses underneath the vertebral lamina.

Results In our institution, the US method is used for patients with thoracic radiculopathy such as thoracic postherpetic neuralgia. The US method can be performed more easily at the bedside compared to the UF method, because there is no need to use a fluoroscopy room or no risk of radiation exposure.

Conclusions In the US method, it is generally possible to reduce the risk of nerve injury and blood vessel puncture as compared with the UF method, because the positional relationship between the nerves, blood vessels, and the needle can be grasped. However, since detection of intravascular injection is impossible, combining fluoroscopy using a contrast agent in the US method can increase the safety.