Elective spinal injections should be performed with imaging guidance, such as fluoroscopy or the use of a radiocontrast agent , unless that guidance is contraindicated.  Imaging guidance ensures the correct placement of the needle and maximizes the physician's ability to make an accurate diagnosis and administer effective therapy.  Without imaging, the risk increases for the injection to be incorrectly placed, and this would in turn lower the therapy's efficacy and increase subsequent risk of need for more treatment.  While traditional techniques without image guidance, also known as "blind injections", can assure a degree of accuracy using anatomical landmarks, it has been shown in studies that image guidance provides much more reliable localization and accuracy in comparison.
In fact, the anatomical studies have demonstrated that after the radicular medullary arteries enter the neuroforamen in the anterior aspect of exiting nerve root and dorsal root ganglion, they often travel a distance superiorly and laterally in the lateral epidural space to join the anterior spinal artery supplying the anterior two thirds of the spinal cord. Additionally, in about 63% of cases of cadaver studies, there is a posterior branch of the radicular medullary artery going to the dorsal aspect of the cauda equina. It is conceivable that the epidural needle in the interlaminar lumbar epidural steroid injection will very likely encounter the radicular medullar artery in the lateral aspect of the epidural space or midline posterior epidural space.