CT-Guided Steroid Injections for Relief of Spine Pain

Some patients may be concerned about the safety of treating radiating back pain with corticosteroid injections in the wake of a recent article in the Los Angeles Times that warned about the risks associated with corticosteroid injections in the spine.

Most of the reported serious complications result from inadvertently injecting steroids with particulate matter into blood vessels close to the injection site, which can lead to brain or spinal cord injury.  The risk of stroke or spinal cord damage from a transforaminal or epidural steroid injection is quite low, and at UCSF two critical considerations allow us to reduce that low risk even further.

The first consideration involves the steroids themselves.  Corticosteroids are a group of medications that may contain particles within solutions, and steroids range in strength and the size of particles within the solutions. There is a higher risk of stroke from steroids that contain particles because the particulate matter can form clusters that could obstruct a blood vessel that supplies the spinal cord or brain. This is referred to as embolization, and it can result in a stroke.  Some corticosteroid solutions contain no particles, carrying less risk of embolization and stroke.

At UCSF, when we are injecting near blood vessels, we use a steroid that has no particles in order to minimize the risk of embolization.

The second critical consideration involves the use of CT scanning to guide our injections.  The community standard for spinal steroid injections involves the use of an X-ray machine called a fluoroscope.  While used routinely throughout the nation, fluoroscopy can only show bones and some elements of soft tissue, but not the nerves themselves or the blood vessels.

UCSF is unique in using CT guidance for needle placement, and we have a dedicated CT scanner for spine interventional procedures at the UCSF Precision Spine and Peripheral Nerve Center.

The CT scanner gives a cross-sectional view of all the vessels and nerves, as well as the spinal cord, so the physician performing the injection can avoid the major vessels that a needle might accidentally penetrate.

CT guidance also provides an additional look at the area of interest at the time of the procedure.  This proves advantageous because sometimes the CT scan actually shows the problem causing the patient’s symptoms to be at a different level than what was suggested by the clinical examination. So what we see in the CT scan at the time of the procedure may prompt us to change the injection to another level or add additional injection sites for maximal relief of pain.  Since fluoroscopy does not reveal the detailed anatomy that is available with CT, additional or different areas of pain generation are not visible, so those other potential areas are rarely identified when using fluoroscopy.

CT guidance has been shown in published medical studies to result in more accurate and precise placement of needles and medication, resulting in better patient care.  We have tailored our CT technique to minimize radiation dose and have shown that the radiation levels for injections with CT guidance are at or below the levels that occur with conventional fluoroscopy.  In fact, to further minimize the patient’s exposure to radiation we often limit the scan to just one or two segments that are of importance instead of scanning the entire spine.

In summary, the patient referred for spinal injections should be aware that complications from these procedures, while rare, may occur, and that these can be minimized by selection of a safer steroid mixture and proper image guidance.  We welcome the worthwhile opportunity to discuss these and other important issues with our patients, and we are available to answer any questions from patients.