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Imaging Dementia—Evidence for Amyloid Scanning (IDEAS) Study


This study will assess the impact of amyloid positron emission tomography (PET) imaging on outcomes in patients with mild cognitive impairment or dementia of uncertain origin. Researchers seek to demonstrate that amyloid PET can help clinicians diagnose the cause of cognitive impairment, provide the most appropriate treatments and recommendations, and improve health outcomes.

Minimum Age Maximum Age Gender Healthy Volunteers
65 Years N/A Both No
February 2016
December 2017

  • Medicare beneficiary
  • Diagnosis of MCI or dementia
  • Cognitive complaint verified by objectively confirmed cognitive impairment
  • Cause of cognitive impairment is uncertain after comprehensive evaluation by dementia specialist, including general medical and neurological examination, mental status testing, laboratory testing, and structural neuroimaging
  • Alzheimer's disease is a diagnostic consideration
  • Knowledge of amyloid PET status is expected to alter diagnosis and management
  • Head MRI and/or CT within 24 months prior to enrollment
  • Clinical laboratory assessment (complete blood count, standard blood chemistry profile, thyroid stimulating hormone, vitamin B12) within 12 months prior to enrollment
  • Able to tolerate amyloid PET imaging
  • English or Spanish speaking
  • Willing and able to provide consent; consent may be by proxy

  • Normal cognition or subjective complaints that are not verified by cognitive testing
  • Knowledge of amyloid status that, in the opinion of the referring dementia expert, may cause significant psychological harm or otherwise negatively impact patient or family
  • Scan ordered solely based on family history of dementia, presence of apolipoprotein E, or in lieu of genotyping for suspected autosomal mutation carriers
  • Scan ordered for nonmedical purposes, such as legal, insurance coverage, or employment screening
  • Cancer requiring active therapy (excluding non-melanoma skin cancer)
  • Hip/pelvic fracture within 12 months prior to enrollment
  • Body weight exceeds PET scanner weight limit
  • Life expectancy of less than 24 months based on medical co-morbidities
  • Residence in a skilled nursing facility

The IDEAS Study will enroll more than 18,000 Medicare beneficiaries who meet criteria determined by dementia specialists participating in the study. All PET scans conducted during the study will be reimbursed by Medicare. Amyloid PET will be performed and interpreted at each facility, with results provided to the ordering physician to support further clinical decisionmaking.

The main hypothesis is that, in diagnostically uncertain cases, knowledge of amyloid status, as determined by amyloid PET imaging, will lead to significant changes in patient management, which will translate into improved long-term outcomes. Investigators will evaluate the impact of amyloid PET on short-term patient management by comparing pre-PET intended management to post-PET actual management 90 days after the scan. The primary objective is to test whether amyloid PET leads to a 30 percent or more change between intended and actual patient management, including drug therapy, other therapy, and counseling about safety and future planning.

Researchers will also assess the impact of amyloid PET results on clinical diagnosis and prevention of unnecessary diagnostic procedures and treatments. They will use Medicare claims data to compare medical outcomes at 12 months for patients with known amyloid PET to control patients who have never undergone amyloid PET. The primary objective is to determine if amyloid PET in the "known" group is associated with a 10 percent or more reduction in hospitalizations and emergency room visits compared to the controls.

The evidence obtained by the IDEAS Study may support reimbursement of amyloid imaging by Medicare and other third-party payers.

For more information about this study and a list of study locations, visit

American College of Radiology Imaging Network

  • Alzheimer's Association

Name Role Affiliation
Gil D. Rabinovici, MD Principal Investigator University of California, San Francisco

Name Phone Email
Cynthia Olson
Leslie Sears


Imaging Dementia—Evidence for Amyloid Scanning (IDEAS) Study: A Coverage With Evidence Development Longitudinal Cohort Study