Fluoroscopically guided transforaminal epidural steroid injections at a quaternary-care teaching institution: Effect of trainee involvement and patient body mass index on fluoroscopy time and patient dose

Aim To investigate whether there are differences in fluoroscopy time and patient dose for fluoroscopically guided lumbar transforaminal epidural steroid injections (TFESIs) performed by staff radiologists versus with trainees and to evaluate the effect of patient body mass index (BMI) on fluoroscopy time and patient dose, including their interactions with other variables. Materials and methods Single-level lumbar TFESIs (n=1844) between 1 January 2011 and 31 December 2013 were reviewed. Fluoroscopy time, reference point air kerma (K_a,r), and kerma area product (KAP) were recorded. BMI and trainee involvement were examined as predictors of fluoroscopy time, K_a,r, and KAP in models adjusted for age and gender in multivariable linear models. Stratified models of BMI groups by trainee presence were performed. Results Increased age was the only significant predictor of increased fluoroscopy time (pa,r and KAP were significantly higher in patients with a higher BMI (pa,r and KAP in all groups (pa,r in any BMI category. KAP was lower with trainees in the overweight group (p=0.0009) and higher in male patients for all BMI categories (pa,r and KAP. Male patients received a higher KAP in all BMI categories. Limiting fluoroscopy time and good collimation practices should be reinforced in these patients.