Fig. 4. Pulsed radiofrequency ablation in the thoracic dorsal root ganglia for the treatment of postherpetic neuralgia (PHN). (A) Oblique view: The target point is below the pedicle. (B) Anteroposterior view: The needle is advanced to the dorsal root ganglion below the pedicle. (C) Lateral view: The depth of the needle is adjusted under the lateral view. A contrast medium spreads to the left posterior epidural space, and the dorsal root ganglia become apparent.
