Fig. 5

A and B The proposed positions of the patient during selective cervical nerve block either oblique “A” or supine “B” at the level of the interventionist eyes. C The pre-procedural measured angle of the targeted neural foramen. The white arrow points to the vertebral artery which lies anterior to the foramen allowing for a safe trajectory for the needle. D Identification of the posterior–inferior aspect of the foramen by placing a curved clamp over the skin with the projected tip at the desired location. E The ideal position of the needle tip at the posterior–inferior aspect of the foramen. The needle is inserted using en face technique in line with the radiation beam, thus appearing as a radio-opaque dot. F Slightly higher, yet an accepted position of the needle tip. (Reproduced and edited from [63])