What are Spect Scans?
A SPECT scan is a type of nuclear imaging test, which means it uses a radioactive substance and a special camera to create 3-D pictures. While imaging tests such as X-rays can show what the structures inside your body look like, a SPECT scan produces images that show how your organs work.
Brain perfusion single-photon emission computed tomography (SPECT) imaging is a functional nuclear imaging technique performed to evaluate regional cerebral perfusion.
Because cerebral blood flow is closely linked to neuronal activity, the activity distribution is presumed to reflect neuronal activity levels in different areas of the brain.
How does a SPECT scan work?
A SPECT scan integrates two technologies to view your body: computed tomography (CT) and a radioactive material (tracer). The tracer is what allows doctors to see how blood flows to tissues and organs.
Before the SPECT scan, you are injected with a chemical that is radiolabled, meaning it emits gamma rays that can be detected by the scanner. The computer collects the information emitted by the gamma rays and translates them into two-dimensional cross-sections. These cross-sections can be added back together to form a 3D image of your brain.
The radioisotopes typically used in SPECT to label tracers are iodine-123, technetium-99m, xenon-133, thallium-201, and fluorine-18. These radioactive forms of natural elements will pass safely through your body and be detected by the scanner. Various drugs and other chemicals can be labeled with these isotopes.
The type of tracer used depends on what your doctor wants to measure. For example, if your doctor is looking at a tumor, he or she might use radiolabled glucose (FDG) and watch how it is metabolized by the tumor.
The test differs from a PET scan in that the tracer stays in your blood stream rather than being absorbed by surrounding tissues, thereby limiting the images to areas where blood flows. SPECT scans are cheaper and more readily available than higher resolution PET scans.
What does a SPECT scan show?
A SPECT scan is primarily used to view how blood flows through arteries and veins in the brain. Tests have shown that it might be more sensitive to brain injury than either MRI or CT scanning because it can detect reduced blood flow to injured sites.
SPECT scanning is also useful for presurgical evaluation of medically uncontrolled seizures. This type of scanning is also useful in diagnosing stress fractures in the spine (spondylolysis), blood deprived (ischemic) areas of brain following a stroke, and tumors.
Brain perfusion SPECT imaging can aid in the diagnosis and ongoing evaluation of many different medical conditions, as follows:
Detection and evaluation of cerebrovascular disease
Aid in the diagnosis and differential diagnoses of suspected dementia
Detection of seizure focus
Assessment of brain death
Evaluating suspected brain trauma
Neuropsychiatric disorders: Mood disorders, evaluating and subtyping attention-deficit disorder
Infection/inflammation(these will take you to a different site)
positron emission tomography (PET): a nuclear medicine test in which tissue function can be imaged. Damaged tissues have reduced metabolic activity; therefore, gamma radiation from these areas is reduced or absent.
Published Research and Facilities that Do SPECT
(these will take you to a different site)
Mayfield Brain and Spine – PDF Explanation
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