MATERIAL and METHODS: This interventional clinical study was conducted on 30 patients with a history of radicular lowback pain and a recent MRI indicating root compression. On the prone position, with the curve of ultrasound transducer on the parasagittal oblique position, a peripheral venous catheter (# 16) was advanced to the lamina through out-of-plane technique. Then, the transducer position was changed to axial position and an epidural catheter was placed about 8 cm away from midline and advanced under sonography guide with the in-plane technique to the intervertebral foramen. The level and the situation of needle was controlled with fluoroscopy and documented when the corticosteroid (triamcinolone) was injected. Also, pain scores for patients were documented and analyzed with SPSS-22 software.

RESULTS: After controlling with fluoroscopy, from all 38 levels of injection, 36 levels were correctly achieved. Of all 36 injections on right levels, all injections were performed in the correct position (in intervertebral foramen). The patients? pain dramatically decreased during the first month after injection (p<0.001), but after that, it remained unchanged.

CONCLUSION: In our study, transforaminal injection was administered using the modified new technique, which was found to be safe and accurate in comparison with the fluoroscopy, as the popular gold standard technique. Keywords : Transforaminal injection, Sonography, Fluoroscopy, Root compression, Low back pain