Featured Research

from universities, journals, and other organizations

PET's Imaging Power May Be Best Indicator For Determining Which Patients Develop Alzheimer's

October 6, 2005
Society of Nuclear Medicine
Positron emission tomography (PET) imaging--with the radiotracer fluorodeoxyglucose (FDG)--is a promising tool in detecting Alzheimer's disease in patients who have mild cognitive impairment (MCI), according to a study reported in the October issue of the Society of Nuclear Medicine's Journal of Nuclear Medicine.

"PET imaging with FDG represents one of the mostpromising tools for diagnosis of Alzheimer's," said Alexander Drzezga,M.D., who is the senior physician with the department of nuclearmedicine at the Technical University of Munich in Germany. In fact,using PET imaging with FDG "may be the best indicator for determiningwhich MCI patients are most at risk of developing Alzheimer's," addedthe lead author of "Prediction of Individual Clinical Outcome in MildCognitive Impairment (MCI) by Means of Genetic Assessment and 18F-FDGPET."

Mild cognitive impairment (MCI) is a term used to describea subtle but measurable deterioration of cognitive capabilities, suchas memory function. Individuals with MCI are able to functionreasonably well in everyday activities, such as managing finances andpurchasing items at stores without assistance, but may have difficultyremembering details of conversations, events and upcoming appointments.

Patientswith MCI do not yet exhibit the criteria for the diagnosis of dementia,but the disorder is seen as a precursor to Alzheimer's disease, whichtakes years to develop in a person, said Drzezga. Many patients withMCI develop a progressive decline in their thinking abilities overtime, and Alzheimer's disease is usually the underlying cause.Alzheimer's is the most common form of dementia among older people; itis a progressive, irreversible brain disorder with no known cause orcure. More than 4.5 million Americans suffer from Alzheimer's and itssymptoms of memory loss, confusion, impaired judgment, personalitychanges, disorientation and loss of language skills.

"A highpercentage of MCI patients will develop Alzheimer's disease within ayear; however, some of these patients will never develop dementia andmay even improve with time," said Drzezga. Most MCI patients who showedabnormalities typical of Alzheimer's in their original PET scandeveloped dementia within 16 months, according to findings from the30-patient study. Most patients who did not show abnormalities in theiroriginal PET scan remained stable, he added.

Patients withAlzheimer's show characteristic changes of the cerebral glucosemetabolic pattern, with a decrease in affected brain regions, saidDrzezga. PET imaging with FDG allows the analysis of regional cerebralglucose metabolism. The study showed that "the assessment of cerebralglucose metabolism actually reflects ongoing pathological changesassociated with Alzheimer's disease on a molecular level and that themolecular imaging method PET is capable of depicting subtle changes inthe brain of MCI patients before a diagnosis of Alzheimer's based onneuropsychological evaluation is possible," said Drzezga.

Thestudy revealed that PET with FDG has a significantly higher accuracyfor detection of Alzheimer's than the genetic screening for theAPOEe4-risk factor. In addition, using both PET with FDG and theAPOEe4-genotype as genetic markers "allowed the definition of subgroupsof patients with very high risk and with very low risk," he added. Thisfinding could have implications for risk stratifying MCI patients intherapeutic trials, said Drzezga. "This study implies that PET—and inconsequence nuclear medicine—should continue to be strongly involved inthe challenging process of Alzheimer's research for early diagnosis aswell as for the development and evaluation of new treatment options,"he added.

Although there is currently no cure for Alzheimer's,new treatments are on the horizon as a result of accelerating insightinto the biology of the disease. "It is of increasing importance toidentify 'converters' at the earliest possible stage of disease todevelop and evaluate new and upcoming treatment options forAlzheimer's," added Drzezga, an SNM member.

PET is a safe,effective and painless biological imaging exam that "photographs" ordetects the presence and extent of neurological conditions. PET usesvery small amounts of radioactive materials that are targeted tospecific organs, bones or tissues. Radiotracers (such as FDG) areinjected and then detected by a special type of camera that works withcomputers to provide precise pictures of the area of the body beingimaged and molecular images of the body's biological functions. "Thecombination of molecular imaging with genotype assessment representsthe unique opportunity to interpret imaging findings in the context ofbackground information," explained Drzezga. "As we increase ourunderstanding of the human genome, individualized therapy andindividualized diagnosis will become increasingly important," he added."The current study underlines that a genetic disposition does notnecessarily represent a determined prognosis, thus, the need formeasures that allow the definition of the actual onset of a diseaseprocess is apparent. Molecular imaging could play an important role inthis context," he stated.

"Prediction of Individual Clinical Outcome in Mild Cognitive Impairment (MCI) by Means of Genetic Assessment and 18F-FDGPET" appears in the October issue of the Journal of Nuclear Medicine,which is published by the Society of Nuclear Medicine. Besides Drzezga,authors include Markus Schwaiger, M.D., department of nuclear medicine,Technical University of Munich, Germany; Timo Grimmer, M.D., MatthiasRiemenschneider, M.D., Panagiotis Alexopoulus, M.D., and AlexanderKurz, M.D., all with the department of psychiatry and psychotherapy,Technical University of Munich, Germany; Nicola Lautenschlager, M.D.,school of psychiatry and clinical neurosciences, University of WesternAustralia, Crawley, Australia; Hartwig Siebner, M.D., department ofneurology, Christian-Albrechts-University, Kiel, Germany, andNeuroImage-Nord, Hamburg, Germany; and Satoshi Minoshima, M.D., Ph.D.,department of radiology, University of Washington, Seattle.

Story Source:

The above story is based on materials provided by Society of Nuclear Medicine. Note: Materials may be edited for content and length.

Cite This Page:

Society of Nuclear Medicine. "PET's Imaging Power May Be Best Indicator For Determining Which Patients Develop Alzheimer's." ScienceDaily. ScienceDaily, 6 October 2005. <www.sciencedaily.com/releases/2005/10/051005231450.htm>.
Society of Nuclear Medicine. (2005, October 6). PET's Imaging Power May Be Best Indicator For Determining Which Patients Develop Alzheimer's. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2005/10/051005231450.htm
Society of Nuclear Medicine. "PET's Imaging Power May Be Best Indicator For Determining Which Patients Develop Alzheimer's." ScienceDaily. www.sciencedaily.com/releases/2005/10/051005231450.htm (accessed July 23, 2014).

Share This

More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.


Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News


Free Subscriptions

Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile

Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?

Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins