Claim: Using PET Scans to Discover Early Signs of Alzheimer’s
Verdict: REFUTES

Retrieved passages:
title: Brain positron emission tomography
text: changes in brain metabolism, which in turn causes easily detectable changes in PET scans. PET is probably most useful in early cases of certain dementias (with classic examples being Alzheimer's disease and Pick's disease) where the early damage is too diffuse and makes too little difference in brain volume and gross structure to change CT and standard MRI images enough to be able to reliably differentiate it from the "normal" range of cortical atrophy which occurs with aging (in many but not all) persons, and which does "not" cause clinical dementia. PET is also actively used for multiple sclerosis and

title: Avid Radiopharmaceuticals
text: with symptoms of Alzheimer's disease detected plaque in a PET scan in areas where it was typically found in the brain. Further tests found that the scans detected plaque in patients with Alzheimer's, didn't find it in those without the diagnosis and found intermediate amounts in patients with early signs of dementia. The tests found amyloid plaque in 20% of its test patients over age 60 that had been in the normal range, but had performed worse than a control group on tests of mental acuity. In order to confirm if the dye was accurate in detecting Alzheimer's, an advisory

title: Alzheimer's disease
text: to low accuracy, the C-PIB-PET scan is not recommended to be used as an early diagnostic tool or for predicting the development of Alzheimer's disease when people show signs of mild cognitive impairment (MCI). The use of ¹⁸F-FDG PET scans, as a single test, to identify people who may develop Alzheimer's disease is also not supported by evidence. There is no definitive evidence to support that any particular measure is effective in preventing AD. Global studies of measures to prevent or delay the onset of AD have often produced inconsistent results. Epidemiological studies have proposed relationships between certain modifiable factors,

title: Florbetapir (18F)
text: of Alzheimer's disease detected plaque in a PET scan in areas where it was typically found in the brain. Further tests found that the scans detected plaque in patients with Alzheimer's, didn't find it in those without the diagnosis and found intermediate amounts in patients with early signs of dementia. The tests found amyloid plaque in 20% of its test patients over age 60 that had been in the normal range, but had performed worse than a control group on tests of mental acuity. In order to confirm if the dye was accurate in detecting Alzheimer's, an advisory committee at

title: Neuroimaging
text: all cause great changes in brain metabolism, which in turn causes easily detectable changes in PET scans. PET is probably most useful in early cases of certain dementias (with classic examples being Alzheimer's disease and Pick's disease) where the early damage is too diffuse and makes too little difference in brain volume and gross structure to change CT and standard MRI images enough to be able to reliably differentiate it from the "normal" range of cortical atrophy which occurs with aging (in many but not all) persons, and which does "not" cause clinical dementia. Single-photon emission computed tomography (SPECT) is

title: Brain positron emission tomography
text: that because the radioactivity decays rapidly, it is limited to monitoring short tasks. Before the use of functional magnetic resonance imaging (fMRI) became widespread, PET scanning was the preferred method of functional (as opposed to structural) brain imaging, and it still continues to make large contributions to neuroscience. PET scanning is also useful in PET-guided stereotactic surgery and radiosurgery for treatment of intracranial tumors, arteriovenous malformations and other surgically treatable conditions. PET scanning is also used for diagnosis of brain disease, most notably because brain tumors, strokes, and neuron-damaging diseases which cause dementia (such as Alzheimer's disease) all cause great

title: Neurotechnology
text: In addition, PET scans have been found to be 93% accurate in detecting Alzheimer's disease nearly 3 years before conventional diagnosis, indicating that PET scanning is becoming more useful in both the laboratory and the clinic. Stem cell technologies are always salient both in the minds of the general public and scientists because of their large potential. Recent advances in stem cell research have allowed researchers to ethically pursue studies in nearly every facet of the body, which includes the brain. Research has shown that while most of the brain does not regenerate and is typically a very difficult environment

title: Florbetapir (18F)
text: 2011 in the "Journal of the American Medical Association", Avid reported on the results of further studies conducted based on 152 test subjects who had agreed to receive the company's PET scans and to have their brains analyzed after death for definitive determination of the presence of amyloid plaques. Of the patients included in the study, 29 who died had autopsies performed on their brains and in all but one the brain autopsy results matched the diagnosis based on the PET scan taken before death. Avid's technique is being used to test the efficacy of Alzheimer's disease treatments being developed

title: Neuroimaging
text: when they first became available. The improved resolution permitted better study to be made as to the area of the brain activated by a particular task. The biggest drawback of PET scanning is that because the radioactivity decays rapidly, it is limited to monitoring short tasks. Before fMRI technology came online, PET scanning was the preferred method of functional (as opposed to structural) brain imaging, and it continues to make large contributions to neuroscience. PET scanning is also used for diagnosis of brain disease, most notably because brain tumors, strokes, and neuron-damaging diseases which cause dementia (such as Alzheimer's disease)

title: Alzheimer's disease
text: infection in the CNS, as found by R. Moir and R. Tanzi in mouse and worm models of AD. Of the many medical imaging techniques available, single photon emission computed tomography (SPECT) appears to be superior in differentiating Alzheimer's disease from other types of dementia, and this has been shown to give a greater level of accuracy compared with mental testing and medical history analysis. Advances have led to the proposal of new diagnostic criteria. PiB PET remains investigational, but a similar PET scanning radiopharmaceutical called florbetapir, containing the longer-lasting radionuclide fluorine-18, is a diagnostic tool in Alzheimer's disease. Amyloid

title: Dementia
text: in assessing long-standing cognitive dysfunction, since they have shown similar ability to diagnose dementia as a clinical exam and cognitive testing. The ability of SPECT to differentiate the vascular cause (i.e., multi-infarct dementia) from Alzheimer's disease dementias, appears superior to differentiation by clinical exam. Recent research has established the value of PET imaging using carbon-11 Pittsburgh Compound B as a radiotracer (PIB-PET) in predictive diagnosis of various kinds of dementia, in particular Alzheimer's disease. Studies from Australia have found PIB-PET 86% accurate in predicting which patients with mild cognitive impairment will develop Alzheimer's disease within two years. In another study,

title: Avid Radiopharmaceuticals
text: without the disease. In results presented in July 2010 to an international conference on Alzheimer's disease held in Hawaii, the company showed that for 34 out of the 35 hospice patients who had been scanned, the initial scan results were confirmed when pathologists counted plaque under a microscope and when a computerized scan of the plaque was performed on material from the autopsied brain. The findings will require review by the FDA to confirm its reliability as a means of diagnosing the disease. If confirmed, the technique would provide a means to reliably diagnose and monitor the progress of Alzheimer's

title: Positron emission tomography
text: of dementia. Less often, other radioactive tracers, usually but not always labeled with fluorine-18, are used to image the tissue concentration of other types of molecules of interest. One of the disadvantages of PET scanners is their operating cost. PET is both a medical and research tool. It is used heavily in clinical oncology (medical imaging of tumours and the search for metastases), and for clinical diagnosis of certain diffuse brain diseases such as those causing various types of dementias. PET is also an important research tool to map normal human brain and heart function, and support drug development. PET

title: Florbetapir (18F)
text: by other pharmaceutical firms as a means of determining the ability of the drugs to reduce the buildup of amyloid protein in the brains of living subjects. On January 20, 2011, an FDA advisory committee unanimously recommended that Avid's PET scan technique be approved for use. The advisory committee included a qualification requiring Avid to develop clear guidelines establishing when the tests had spotted enough of the amyloid plaque to make a diagnosis of Alzheimer's, a task that Avid CEO Daniel M. Skovronsky stated could be resolved in several months. Avid Radiopharmaceuticals was based at the University City Science Center

title: Florbetapir (18F)
text: the Food and Drug Administration demanded that the team of Avid, Bayer and General Electric perform a study to test their method. Avid established a study with a group of 35 hospice patients, some that had been diagnosed with dementia and others that had no memory problems. The participants and their families agreed that they would undergo the PET scans and would have their brains autopsied after their death by pathologists. After the study was conducted, Avid received confirmation in May 2010 that the results of the test were successful in distinguishing between those with Alzheimer's and those without the

title: Florbetapir (18F)
text: disease. In results presented in July 2010, the company showed that for 34 out of the 35 hospice patients who had been scanned, the initial scan results were confirmed when pathologists counted plaque under a microscope and when a computerized scan of the plaque was performed on material from the autopsied brain. The findings required review by the FDA to confirm their reliability as a means of diagnosing the disease. Once confirmed, the technique provideed a means to reliably diagnose and monitor the progress of Alzheimer's and allowed potential pharmaceutical treatments to be evaluated. In a study published in January

title: Concussions in American football
text: living players, are associated with Alzheimer's disease. Previously, this type of exam could only be performed with an autopsy. Scientists at UCLA created a chemical marker that binds to the abnormal proteins and they are able to view this with Positron Emission Tomography (PET) scan. Researcher at UCLA, Gary Small explains, "Providing a non-invasive method for early detection is a critical first step in developing interventions to prevent symptom onset and progression in CTE". Post-Concussive Symptoms (PCS) is an area of recovery that is often not discussed. New evidence suggest that new recovery protocols have been recommended and designed to

title: Avid Radiopharmaceuticals
text: Avid's technique is being used to test the efficacy of Alzheimer's disease treatments being developed by other pharmaceutical firms as a means of determining the ability of the drugs to reduce the buildup of amyloid protein in the brains of living subjects. On January 20, 2011, an FDA advisory committee unanimously recommended that Avid's PET scan technique be approved for use. The advisory committee included a qualification requiring Avid to develop clear guidelines establishing when the tests had spotted enough of the amyloid plaque in order to make a diagnosis of Alzheimer's, a task that Avid CEO Dr. Daniel M.

title: Neuroimaging
text: machines to cut imaging time and give higher resolution. Like PET, SPECT also can be used to differentiate different kinds of disease processes which produce dementia, and it is increasingly used for this purpose. Neuro-PET has a disadvantage of requiring the use of tracers with half-lives of at most 110 minutes, such as FDG. These must be made in a cyclotron, and are expensive or even unavailable if necessary transport times are prolonged more than a few half-lives. SPECT, however, is able to make use of tracers with much longer half-lives, such as technetium-99m, and as a result, is far

title: Frontotemporal dementia
text: MRI scans often reveal frontal lobe and/or anterior temporal lobe atrophy but in early cases the scan may seem normal. Atrophy can be either bilateral or asymmetric. Registration of images at different points of time (e.g., one year apart) can show evidence of atrophy that otherwise (at individual time points) may be reported as normal. Many research groups have begun using techniques such as magnetic resonance spectroscopy, functional imaging and cortical thickness measurements in an attempt to offer an earlier diagnosis to the FTD patient. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) scans classically show frontal and/or anterior temporal hypometabolism, which helps