Interpretation of contrast dispersal patterns by experienced and inexperienced interventionalists

Determine how accurately inexperienced interventionalists interpret epidural contrast dispersal patterns compared with experienced interventionalists.

Prospective comparative study.

University spine center.

Two experienced interventionalists and 3 pain fellows in training.

Each participant independently interpreted 100 images showing contrast dispersal patterns from transforaminal epidural injections. All images were obtained by another physician after 0.5 mL of contrast material was injected. The true contrast dispersal pattern was determined under live fluoroscopy during the injection and classified as follows: epidural only, vascular only, or simultaneous epidural and vascular. Participants were told to assume that 0.5 mL of contrast had been injected before each image and were asked to describe the contrast patterns as epidural, vascular, both, or neither.

Variance in agreement with the true contrast patterns between experienced and inexperienced participants.

Overall, the inexperienced participants were in exact agreement with the true pattern in 52% of the images versus 70% for experienced participants (P=.03). Experienced participants correctly identified epidural contrast patterns with greater accuracy than inexperienced participants (94% and 76%, respectively; P=.01). Not surprisingly, the accuracy for all participants was low in the identification of vascular patterns on these static images, with 73% accuracy for the experienced and 68% for the inexperienced (P=.18).

Even with 6 months of intensive experience, trainees are significantly less accurate than experienced physicians in the interpretation of contrast dispersal patterns from transforaminal epidural injections. The competency of interventional trainees and the amount of experience necessary to safely perform epidural injections deserve further examination.