PET Scan

The photons are then tracked by a tomographic scintillation counter, and the information is processed by a computer to provide both image and data on blood flow and metabolic processes within bodily tissues. PET scans are particularly useful for diagnosing brain tumor and the effects of strokes on the brain, along with various mental illnesses. They are also used in brain research and in mapping of brain functions.

     The brain function being studied during a PET scan determines which positron-emitting radiopharmaceutical is used. Oxygen-15 can be used to label oxygen gas for the study of oxygen metabolism, carbon monoxide for the study of blood volume, or water for the study of blood flow in the brain. Similarly, fluorine-18 can be attached to a glucose molecule to produce 2-fluoro-2-deoxy-D-glucose (FDG) for use in the observation of the brain’s sugar metabolism.

During the last decade, major progress has been made in the treatment of disease with radioisotopes. Treatments involving the use of medical isotopes are gaining momentum in the race against many types of cancer. FDA approved and highly promising therapies are doubling every 3 to 4 years. Some researchers predict that over 80% of cancer types should be treatable with

A reduction on the regional uptake of 18F labeled fluordeoxyglucose is another biomarker of AD that is measured by PET (Kazemifar et al., 2017). Amyloid PET scan is a new imaging technique that directly visualize the amyloid plaques in the brain with high affinity binding of Amyvid (Florbetapir F-18) (Page et al., 2017). A positive amyloid scan indicates moderate to frequent amyloid plaques (Page et al., 2017). Amyloid scan should be utilized in addition to clinical diagnostic evaluation since elderly patients without AD can have a degree of accumulation of amyloid plaque (Page et al., 2017). A negative amyloid imaging is significant in a patient who has a clinical diagnosis of AD, could indicate a misdiagnosis and oftentimes produce changes in therapeutic planning (Page et al., 2017). A positive PET scan highly indicates fibrillary amyloid beta which is a hallmark of AD (Grill et al., 2017). An increased amyloid

• A PET (positron emission tomography) scan may help to show cancer activity in some other parts of the body. This can be helpful for “staging” the cancer (see

New functions of the brain are now clear due to new technologies. The positron emission tomography (PET) scan and the functional magnetic resonan imaging (FMRI) scan are two ways of imaging the brain in action. PET scans measure blood flow in the brain. To produce the PET scan, a person is injected with a slightly radioactive substance, unlike the FMRI scan, where an injection isn't necessary. The substance travels through the blood to the brain where it collects in active areas.The scans produce colored maps of brain activity.

The radioisotope Fluorine-18 is a radioactive isotope of fluorine. Fluorine has nine protons and ten neutrons, fluorine-18 has only nine neutrons which is less than normal. F-18 produces gamma radiation in the body, gamma rays are electromagnetic waves with an extremely high frequency, unlike alpha and beta radiation, gamma has no mass, and travel at a speed of light with the ability to penetrate human skin, only stop by lead. F-18 is used as a tracer in nuclear medicine imaging, specifically positron emission tomography (PET) scans. PET scans are used to provide precise and sophisticated three dimensional images for diagnosis of diseases within the body such as cancer. During its creation in the cyclotron particle accelerator, F-18 is combined

There are a few alternatives to using fMRI such as positron emission technology (PET), but fMRI holds many advantages over PET as fMRI does not require radioactive injections, its total scan time is usually very short, and it is suitable to assist in a neurosurgical treatment plan for specific individuals (Columbia University, 2010).

A PET scan does not only look at the size and shape of the brain, is also looks at and assesses the function. Meaning it tells you how the brain is working. There is little doubt that as we age structural changes happen in our brain. A way to test for this is to use neuroimaging techniques while performing certain tasks (i.e. recall or reading of names, etc. to test memory).

Furthermore, the cost of Nuclear Imaging is relatively high and, as a result, is not being commonly installed in hospitals. The reason is the necessity of having the PET facility close to a cyclotron since the useful radioisotopes have small half-lives; thus the time between its production and the final injection must be small. In this way, the optimal use of high levels of radioactivity during the first few half-lives can be utilised to produce high-quality images (Andrew Olesnicky, Neville Lawrence,

PET scans can identify several cancers, heart diseases, and brain disorders before other examinations determine conditions therefore physicians are able to better diagnose conditions. Factors which cause error in diagnosis includes allergic reactions, small amount of radiation exposure to fetus as well as breastfeeding from tracer drug (Mayo Clinic, n.d,

Another search in Medline/Pubmed was performed via PICO. The search was done as follows. Patient/Problem: neoplasm, Intervention: Diffusion weighted imaging , Compare to: fdg, Outcome: accuracy. This gave a total of 26 results. From these 26 articles 5 were included into this review (2) (3) (4) (5) (6). Exclusion of articles was based on: the absence of statistical numbers, not being a clinical trial, and the participation of less than 25 patients.

Nuclear Medical Imaging (NMI) uses small amounts of radiopharmaceuticals or radiotracers to diagnose, evaluate and treat a variety of diseases such as cancer, heart disease, gastrointestinal, endocrine, neurological and skeletal disorders (McKinnis, 2014; RadiologyInfo.org (2014b). In comparison with other radiographic procedures, except for intravenous injections, NMI is noninvasive and diagnoses disease based on the physiological or functional changes of the tissue, organ, bone or system within the body rather than structural changes of anatomy (McKinnis, 2014; RadiologyInfo.org, 2014b; Smith, n.d.). These radiotracers are either injected, ingested or inhaled as a gas into the body and absorbed by the organ or area of the body to be examined

The technology that is being investigated is the PET scan. The PET scan functions as a result of the specific atomic properties of positrons which are subatomic particles that have the opposite charge of electrons but the same mass. The PET scanner detects these positrons which are emanated by the radioactive chemicals attached to a chemical the body naturally metabolizes (Positron Emission Tomography, 2014). The PET scan is used in the fields of oncology, neurology, and cardiology to determine the flow of blood, the functionality of the organs, the health of heart tissue, the movement of cancer, and so forth (Positron Emission Tomography, n.d.). This technology works by inserting the patient with a radioactive material through injection,

Over the past decades medical imaging has increased rapidly, and fluoroscopy is one of main contributors to radiation exposure. Fluoroscopy is a commonly used medical technique that uses real-time live images with a continuous x-ray beam to see the internal structures of the body. It can gauge respiratory function or evaluate motility and function of the pharynx, esophagus, stomach, bowel, pumping of the heart, or placement of catheters in the veins or arteries. It also has the ability to look at many body systems, including the skeletal, digestive, urinary, cardiovascular, respiratory, and reproductive systems. The radiation beam in fluoroscopy procedures is typically directed at a moderately small patch of skin for a considerable length of