Comparison of patient radiation exposure and procedure time between CT-fluoroscopy and spiral CT for lumbar epidural steroid injections.

Objective: To compare patient radiation exposure and procedure time for lumbar epidural steroid injections (ESIs) performed under CT-fluoroscopy (CTF) vs spiral CT-guidance.

Materials and methods: A retrospective cohort study of 767 consecutive lumbar ESIs performed between 2015-2023 using CTF vs spiral CT-guidance was conducted. Patient characteristics (age, sex, weight), procedural characteristics (injection level, type of ESI, trainee participation), and outcomes (patient radiation exposure, procedure time, pain relief, complications) were compared. Student's t and chi-squared tests were performed for statistical analysis.

Results: There were 240 CTF and 527 spiral CT-guided lumbar ESIs. There were no significant differences in patient demographics between groups. Radiation exposure for the CTF group was 37.2 ± 50.5 mGy $\bullet$ cm, compared to 251.1 ± 178.6 mGy $\bullet$ cm in the spiral CT group (p < 0.001). Procedure times were shorter in the CTF group (20.1 ± 6.1 vs 29.6 ± 12.9 min, p < 0.001). There was no significant difference in immediate post-procedure pain reduction in CTF vs spiral CT groups (p = 0.12). There were no intrathecal puncture complications in the CTF group and four in the spiral CT group. Subgroup analysis of attending-only and trainee-performed lumbar ESIs comparing CTF vs spiral-CT groups showed similar results as the primary analysis, with significant reductions in patient radiation (attending: 31.6 ± 40.7 vs 144.4 ± 97.4 mGy $\bullet$ cm; trainee: 40.7 ± 55.5 vs 264.5 ± 182.0 mGy $\bullet$ cm; both p < 0.001) and procedural time (attending: 18.3 ± 4.2 vs 24.4 ± 7.4 min; trainee: 21.2 ± 6.8 vs 30.2 ± 12.4; both p < 0.001).

Conclusion: Image-guided lumbar ESIs using CTF were associated with less patient radiation exposure and shorter procedure times without differences in pain relief when compared with spiral CT technique in our practice.