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.


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).


CONCLUSIONS
The radiation dose was small during a single procedure of ESI and showed differences between different lumbosacral spine levels.
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea. ; Department of Radiology, Gachon University Gil Hospital, Incheon 405-760, Korea.
Yun Mi
YM
Hwang
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
Min Hee
MH
Lee
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea. ; Department of Radiology, Inje University Haeundae Paik Hospital, Busan 612-896, Korea.
Seon-Jeong
SJ
Kim
Department of Radiology, Gachon University Gil Hospital, Incheon 405-760, Korea.
Sheen-Woo
SW
Lee
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
Hye Won
HW
Chung
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
Sang Hoon
SH
Lee
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
Myung Jin
MJ
Shin
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D007268:Injections, Epidural; D017116:Low Back Pain / Q000188:drug therapy; D008161:Lumbosacral Region / Q000294:innervation*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D055815:Young Adult
Dose area product; Epidural steroid injection; Fluoroscopy; Fluoroscopy time