Comparison of Radiation Exposure during Fluoroscopy-Guided Transforaminal Epidural Steroid Injections at Different Vertebral Levels

OBJECTIVE To estimate and compare radiation exposure during transforaminal fluoroscopy-guided epidural steroid injection (TFESI) at different vertebral levels. MATERIALS AND METHODS Fluoroscopy-guided TFESI was performed in 181 patients. The patients were categorized into three groups according to the injected lumbosacral nerve level of L2-4, L5, or S1. Fluoroscopy time (FT) and dose area product (DAP) were recorded for all patients; correlations between FT and DAP were determined at each level, and both FT and DAP were compared between the different vertebral levels. RESULTS The numbers of patients who received ESI at L2-4, L5, and S1 were 29, 123, and 29. Mean FT was 44 seconds at L2-4, 33.5 seconds at L5, and 37.7 seconds at S1. Mean DAP was 138.6 µGy·m(2) at L2-4, 100.6 µGy·m(2) at L5, and 72.1 µGy·m(2) at S1. FT and DAP were positively correlated in each group (p values < 0.001). FT was significantly shorter at L5 than that at L2-4 (p = 0.004) but was not significantly different between S1 and L2-4 or L5 (p values = 0.286 and 0.532, respectively). DAP was significantly smaller at L5 and S1 than that at L2-4, but L5 and S1 were not significantly different. After correcting for FT, DAP was significantly smaller at S1 than that at either L2-4 or L5 (p values = 0.001 and 0.010). CONCLUSION The radiation dose was small during a single procedure of ESI and showed differences between different lumbosacral spine levels.