Fluoroscopic axial imaging in percutaneous lumbosacral procedures: An underutilized technique.

Background: The L4-5 and L5-S1 intervertebral disc spaces are the most frequent sites of discal spinal pathology, hence, diagnostic and therapeutic interventions are commonly performed at these levels. While performing fluoroscopically guided spinal procedures such as discography or intradiscal electrothermal anuloplasty (IDEA), antero-posterior (AP), lateral, and oblique views are utilized. However axial projection is not typically possible without three-dimensional imaging such as computerized tomography (CT). Intraprocedural CT is not commonly available. Instead, post-discography CT axial views are used to grade the degree of disruption. However, post-procedural CT is not always immediately available, and it increases costs and may increase patient discomfort, inconvenience, and radiation exposure. Intra-procedure fluoroscopic axial (F-axial) views offer the benefit of dynamic information by helping confirm needle, introducer, or intradiscal catheter position.

Objective: To describe an alternative approach to axial imaging of the L5-S1 intradiscal space.

Setting: Spine Speciality Center.

Technique: We describe a simple technique for visualizing L5-S1 axial images intra-procedurally using F-axial views. Taking advantage of the patient's lordosis, the C-arm image intensifier is rotated cadally so F-axial images are obtained. We also demonstrate other uses of intra-procedural F-axials, including confirmation of discography needle placement and IDEA introducer and catheter positioning.

Conclusion: The L4-5 and L5-S1 intervertebral disc spaces are frequent sites of discal spinal pathology. Multiple diagnostic and therapeutic procedures are performed at these levels. This report describes an adjunctive technique for visualizing the L5-S1 axial images intra-procedurally using a fluoroscopic axial (F-axial) view.