In the past 20 years, radiology has seen the emergence of hybrid diagnostic imaging machines. This technology, such as the Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT), allows for quicker turnaround times, better image results, and ultimately a better patient experience. Discover how SPECT/CT machines help make this possible.
SPECT/CT technology has evolved rapidly in the last decade. Once not widely available in nuclear medicine departments worldwide, it is now routinely used in diagnostic imaging.1
The acronym SPECT/CT means a hybrid scanner, where the camera, otherwise known as the “gantry”, includes one SPECT (single photon emission computed tomography) scanner and one CT (computed tomography) scanner. This technology eliminates the issue of a patient having to move to be scanned on two separate devices.
Commonly used to diagnose heart problems and skeletal and gastrointestinal disorders, SPECT scans allow doctors to analyze the function and physiological processes of internal organs with the injection of a radioactive substance and a special camera to take 2D or 3D pictures.2
With the addition of the 3D images from the CT scan, radiologists are able to accurately identify the anatomic location. SPECT/CT scans clarify issues in cardiac, general nuclear medicine, oncologic and neurologic applications where SPECT scans alone were inconclusive.3
Role of a Technologist
It is up to Radiologic Technologists RT(N) and Certified Nuclear Medicine Technologists (CNMT) to not only take the images of a patient’s internal organs and other functions but also to make sure the equipment is up to date and functioning at its best.
Arguably, the most important role technologists have is patient comfort. This is a consideration for all medical imaging procedures, including SPECT/CT. One important part of the technologist’s role is to treat patients in a professional manner and not disclose the interpretation of the scans.4
How SPECT/CT differs from other modalities
SPECT/CT scanners are not the only hybrid scanners used for diagnostic imaging. Depending on the organ or tissue in question, positron emission tomography (PET) in conjunction with computed tomography (CT) may identify body changes at a cellular level and possibly detect the early onset of disease.
The main difference between SPECT/CT and PET/CT is the type of tracer being used for imaging. SPECT uses a single photon emitter while PET positron uses a positron emitter that emits 2 photons in 180deg in opposite directions.5
How SPECT/CT Scans Can Save Time
Because the SPECT/CT is a hybrid machine, it may save referring physicians, radiologists, technologists and ultimately the patients time.6 Here are several ways it makes this possible:
- Provides Clarity: When other diagnostic imaging results have proved inconclusive, SPECT/CT is a viable next step to provide clarity and help radiologists and doctors make an accurate diagnosis.
- Better Lesion Detection: One study indicated that SPECT/CT performs better in the assessment of endocrine and neuroendocrine tumors, with improved lesion localization and characterization.
- Possible Shorter Scan Time: While it depends on the type of scan being administered, some SPECT/CT scans take between 30-45 minutes. In contrast, PET/CT scans can take up to two hours.
Emerging Trends in SPECT/CT
Here are some of the top trends in SPECT/CT to monitor:
Theranostics: In a November 2018 study, theranostics was referred to as the “epitome of personalized medicine.”7 With theranostics, the goal is to find the right treatment for the patient at the right time. In terms of SPECT/CT, this aligns nuclear medicine clinical research with standard medical and radiation oncology protocols, setting a precedent for individualized molecular oncology and precision medicine.8
Reduced Radiation: This is a common theme going forward in radiology. Researchers and medical professionals are searching for ways to further reduce a patient’s radiation exposure.9
Whole-body SPECT/CT: Unlike planar SPECT/CT, whole-body SPECT/CT has acquisition from “the base of the skull to the proximal femurs.”10 In comparison with planar SPECT/CT, whole-body SPECT/CT has a significantly higher sensitivity and is better able to detect bone metastases and extra-axial metastases.11
- “Clinical Applications of SPECT/CT.” Radiology Society of North America. April 23, 2015. (Accessed February 20, 2019) Available online: https://pubs.rsna.org/doi/full/10.1148/radiol.2015154009
- “SPECT Scan.” Mayo Clinic. (Accessed February 25, 2019). Available online: https://www.mayoclinic.org/tests-procedures/spect-scan/about/pac-20384925
- Bybel, Bohdan, et al. SPECT/CT Imaging: Clinical Utility of an Emerging Technology. Radiographics. July 1, 2008. (Accessed February 24, 2019). Available online: https://pubs.rsna.org/doi/full/10.1148/rg.284075203
- “Everything You Need to Know about Becoming a Radiologic Technologist.” Florida National University. February 27, 2018. (Accessed February 25, 2019). Available online: https://www.fnu.edu/radiologic-technologist/
- “Nuclear Medicine.” National Institute of Biomedical Imaging and Bioengineering. https://www.nibib.nih.gov/. Accessed February 27, 2019.
- Soo, Geoffrey, M.D., Cain, Timothy, M.D. “SPECT-CT Scan.” https://www.insideradiology.com.au/spect-ct-scan/. Accessed February 25, 2019.
- Turner, JH. “An introduction to the clinical practice of theranostics in oncology.” https://www.ncbi.nlm.nih.gov/pubmed/30179054. Accessed March 27, 2019.
- “What is Theranostics?” Theranostics Australia. http://theranostics.com.au/what-is-theranostics/. Accessed March 27, 2019.
- 2018 CT Market Outlook Report. IMV Medical Information Division. November 2018. (Accessed February 19, 2019).
- “Whole-Body SPECT/CT versus Planar Bone Scan with Targeted SPECT-CT for Metastatic Workup.” EurekaMag.com. https://eurekamag.com/research/060/477/060477308.php. Accessed March 27, 2019.
- “Whole-Body SPECT/CT versus Planar Bone Scan with Targeted SPECT/CT for Metastatic Workup.” National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5546128/. Accessed March 27, 2019.