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Lower Cervical Nerve Root Block using CT Fluoroscopy in Patient with Large Body Habitus: Another Benefit of the Swimmer’s Position 2006

Interventional Spine

Walter S Bartynski, MD, ASSR Member
William E Rothfus, MD, ASSR Member
Rex B Jennings, DO, Non ASSR Member

Scientific Poster

Purpose

Cervical nerve root block/steroid injection (CNRB) is commonly performed with CT Fluoroscopy (CTF). This procedure can be a challenging, in particular at lower cervical levels and in patients with a large body habitus (LBH) due to difficulty in obtaining acceptable image quality or limitations in foramen access options. Compromised visualization of critical structures including the carotid artery, jugular vein, vertebral artery and neural foramen can occur. The swimmers position has recently been advocated as a potential solution to improving image quality in the lower cervical spine for diagnostic CT. (1) We recently encountered several patients with LBH and lower cervical radiculopathy in which we modified our standard CNRB technique employing a swimmers position for improved visualization and access to the lower cervical foramina. We describe here our experience with this technique modification.

Methods & Materials

CNRB was performed in six patients with LBH and lower cervical radiculopathy. Patients were placed in the swimmers position after initial scout scan resulted in suboptimal visualization of critical anatomic structures. CNRB was performed in the swimmers position using CTF and standard 25 gauge needle technique. Needle tip location was verified with a small non-ionic contrast test injection and CNRB was obtained with a mixture of 80mg methylprednisolone acetate and 2cc Bupivicaine 0.25%.

Results

Adequate visualization of critical structures was obtained with CTF in the swimmers position employing only minor modification of standard mAs and KVp settings. This was due to a significant decrease in tissue mass encountered by the CT beam. The ability to use CTF allowed rapid access to the neural foramen even in these patients with LBH resulting in short CNRB procedure time. All CNRBs were successful. No complications were encountered.

Conclusion

CNRBs at low cervical levels can be successfully performed with CT Fluoroscopy in large patients by employing the swimmers positioning to reduce scanned tissue mass and improve trajectory options.

References

1. Kane AG, Reilly KC, Murphy TF. Swimmer's CT: Improved Imaging of the Lower Neck and Thoracic Inlet. AJNR Am J Neuroradiol 2004; 25:859-862