A recent prospective study in Interventional Pain Medicine delivers a clear takeaway for lumbar interlaminar epidural steroid injections: an AP fluoroscopic view alone is not reliable for confirming epidural contrast spread.
Researchers compared image interpretation using AP versus contralateral oblique (CLO) views. They created a mix of true epidurograms and deliberate non-epidural contrast patterns, then asked ten experienced pain physicians to classify them in a blinded format.
The results were striking:
AP view: Only 51% accuracy for identifying true epidural spread, with poor agreement among reviewers.
CLO view: 96–99% accuracy, with excellent inter-rater reliability.
The AP view simply lacks depth information; extradural patterns can easily mimic epidural spread when viewed straight-on. CLO, by contrast, clearly shows the interlaminar window, needle depth, and characteristic epidural flow patterns—even with small contrast volumes.
Practical takeaway:
Relying on an AP-only confirmation risks misclassification of contrast spread. Incorporating a CLO view provides far more consistent and accurate confirmation of true epidural entry and should be considered a best-practice imaging approach for lumbar interlaminar injections.
This concise study reinforces a simple point: the AP view doesn’t tell the full story—CLO does.
Link to Journal Article Here
Link to Journal Article Here
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