Technology: SPECT-CT: A Valuable Diagnostic Tool for Spinal Pain

Novel use of old imaging modality can uncover the source of hidden problems.

The complexity of the spine includes many moving parts that can make it challenging to pinpoint a patient’s pain. Many patients today also have spinal instrumentation obstructing a clear view of spinal anatomy.

Root of the problem

To identify where pain is generating, we look to structures that are abnormal and contributing to the pain. Yet two patients with similar anatomy may present with different pain complaints. In order to define the source of pain, spine surgeons use radiographic modalities that are anatomic in nature. This means they must often make assumptions as they develop pain treatment plans around anatomic imaging that is insufficient to reach a definitive conclusion. But what else can we do?

SPECT-CT combines computed tomography and single-photon emission computed tomography to provide functional and anatomic imaging in one scan. I’m not the first neurosurgeon to discuss SPECT-CT as a spinal pain diagnostic tool. However, I am certainly an advocate for it. I use it frequently in my practice at DISC Sports & Spine Center in Valencia, Calif. Although this imaging modality is readily available, its application in diagnosing spinal pain is still underappreciated and underused. My practice has changed dramatically because of my access to such technology and the opportunity to hone in on the precise source of pain.

New upgrade to an old imaging modality

The combined CT and SPECT modality is a newer upgrade to older CT imaging techniques commonly used for other applications such as identifying metastatic cancers throughout the body in oncology patients. SPECT is a nuclear medicine test using an injected radiotracer that excites white blood cells to assess the perfusion and functionality of specific tissues. When combined with CT scan to register detailed anatomic structures, the SPECT-CT can indicate a very specific source of the greatest area of inflammation where white blood cells are most concentrated against an exact anatomic location. Software developments and more advanced reconstruction algorithms for this imaging technology have significantly improved image quality.

I first learned about this imaging modality when a radiologist colleague recommended I assess it at our hospital. I was well aware of SPECT-CT, but the quality has improved to such a degree over the past decade that its diagnostic value has similarly expanded.

I trialed it for several of my patients with spinal pain that was challenging to locate. While I held little hope for a miracle diagnostic advance, I was very pleased to find just that. The scans showed the source of pain and, confidently, I provided the patient a precise treatment plan.

What a joy it has been to sit down with patients experiencing chronic pain —even after multiple surgeries — who were referred to me looking for hope and have the diagnostic tool to give them just that. SPECT-CT allows me to tailor individual treatments for many of my patients to help them achieve very effective pain relief. For some of my patients whose continued pain has required surgical intervention, their SPECT-CT scan helped me create a more precise surgical plan to resolve their pain. This is why I use SPECT-CT in my practice, and I’ve converted several colleagues to do the same. I truly believe it can improve how we diagnose spinal pain.

Game changer for axial pain

One important indication for SPECT-CT is axial pain, which can be challenging to assess using standard anatomic imaging. Because SPECT-CT provides a three-dimensional, functional view of a patient’s spine inflammation in the context of anatomic location, this detail helps identify which element of the spinal anatomy is the source of pain. For example, when a patient has axial pain tied to multiple pain triggers, a SPECT-CT scan of the pain region can show a greater level of detail than a CT or MRI to help determine each area that is triggering pain.

Considerations for SPECT-CT usage

I encourage any neurosurgeon or spine surgeon looking to improve their diagnostic toolkit for better pain source identification to explore the SPECT-CT modality. Here are three ways I’ve optimized how to order and analyze these scans to provide more diagnostic information.

“A SPECT-CT scan of the pain region can show a greater level of detail than a CT or MRI.”

First, it’s important to confirm the SPECT-CT technology you will order for your patient is the most current to ensure scan specificity. If the technology can identify the radioisotope update in the small cervical facet joints, it reflects the recent upgrade. If the radiology group you work with is open to upgrades, it’s not a huge investment if they have the equipment. Second, once you confirm the scan will be optimized for spine pain diagnosis, I recommend trialing SPECT-CT scan with a few patients, especially patients with pain that is difficult to locate. You’ll start to see the value of this imaging modality and use it more often.

Lastly, I recommend collaborating with a radiologist who specializes in SPECT-CT to learn more about how to leverage this technology in practice. I’ve found tremendous benefit in speaking with my radiology colleagues about individual scans and even reviewing them together.

View toward the future

I encourage experts working in any realm of spine pain management to consider SPECT-CT as a valuable diagnostic tool. I’m a firm believer in continuously looking for new ways to help my patients, and this tool gives me the comfort and confidence to ensure an unambiguous diagnosis and design the perfectly targeted treatment plan for it. OSM