Open-label, non-randomized, multi-centre positron emission tomography (PET) imaging study to evaluate a single dose of 250 MBq BAY858102 ([F-18]DPA-714) for its diagnostic potential in discriminating patients with probable Alzheimer's disease from healthy volunteers and to evaluate the radiation dosimetry of a single dose of 150 MBq BAY858102 ([F-18]DPA-714) in healthy volunteers

Inclusion criteria for AD Patients , Healthy volunteers for brain and whole body imaging
1. Participants must be able to understand the information provided on purpose and conduct of the clinical study, must be capable of giving fully informed consent in writing, and have read and signed the informed consent prior to study participation.
2. Male or females >= 50 years of age.
3. Females of child-bearing potential must provide:
- Agreement to practice adequate contraception methods (abstinence, intrauterine
contraceptive device [IUCD], condoms, oral contraceptives, or other adequate barrier contraception)
- barrier contraception has to be in combination with local application of a
spermicide and
- Negative urine pregnancy test results (beta-HCG)
For females >= 60 years of age postmenopausal status will be determined by medical history (last spontaneous bleeding at least 1 year prior to radiotracer administration or hysterectomy or a bilateral oophorectomy at least three months prior to radiotracer administration).;Additional inclusion criteria for healthy volunteers for brain imaging only
1. Adequate visual and auditory acuity to complete neuropsychological testing.
2. MMSE score of >= 28
3. CDR score of zero (0)
4. Confirmation by other neuropsychological test results that the volunteer does not show any signs of cognitive impairment or dementia (e.g. results lying within an interval of one standard deviation from the mean value, mean value and standard deviations adjusted for age and education);Additional inclusion criteria for probable AD patients only
1. Adequate visual and auditory acuity to complete neuropsychological testing.
2. Patient fulfills DSM-IV and NINCDS-ADRDA criteria for probable AD, which are
cognitive deficits such as memory decline and impairment in at least one other cognitive domain (aphasia, apraxia, agnosia or executive dysfunction).
3. Patient has mild to moderate dementia :
- with a dementia score of >= 20 on the Mini-Mental Status Examination (MMSE)
- with a Clinical Dementia Rating score of 1 or 2 (CDR)
4. Patient has had the following further tests:
- Neurological examination
- Psychometric testing
- Brain MRI

Exclusion criteria: healthy volunteers for brain and whole body imaging and probable AD patients
1. Any disease, condition, or concomitant medications that significantly compromises the function of the body systems and could result in excessive accumulation, impaired metabolism, altered excretion of the radiotracer, or might interfere with the conduct of the study or interpretation of the results.
2. Current unstable medical condition (e.g. unstable angina, myocardial infarction or
coronary revascularization in the preceding 12 months, cardiac failure, chronic renal
failure, chronic hepatic disease, severe pulmonary disease, blood disorders, poorly
controlled diabetes, chronic infection)
3. Current systemic autoimmune disease or clinically relevant systemic inflammatory
disease.
4. History of cancer or current cancer, including brain tumors.
5. History of or current alcohol or drug abuse/dependence or suspicion of alcohol or drug abuse/dependence.
6. History of anaphylactoid or anaphylactic reactions to any allergen including drugs and contrast media.
7. Pregnancy or lactation.
8. History of significant occupational exposure to ionizing radiation or application of
radioactive substances or ionizing radiation for the purposes of diagnosis or treatment within the last year according to recommendations from current guidelines, or whose occupational exposure to radioactivity is monitored or (Netherlands only) application of radioactive substances or ionizing exposure to radiation during an investigation / study in the year preceding the PET scan
9. Haematological or biochemical parameters that are outside the normal range and are considered clinically significant by the investigator, in particular the presence of hepatitis B virus surface antigen (HBsAg), hepatitis C virus antibodies (anti-HCV) or human immune deficiency virus antibodies (anti-HIV). Minor deviations in lab parameters that are considered by the evaluating physician to be not clinically significant with respect to safety or interpretation of study results are not considered an exclusion criterion.
10. Clinically relevant findings in the 12 lead ECG as determined by evaluating physician.
11. Donation of blood within 4 weeks (12 weeks for Finland only) or plasmapheresis within 2 weeks before the radiotracer administration.
12. Criteria which in the opinion of the investigator preclude participation for scientific reasons, for reasons of compliance, or for reasons of the subject*s safety.
13. Subject is in custody by order of an authority or a court of law.
14. Exclusion periods from other studies or simultaneous participation in other clinical studies or previous assignment to radiotracer administration in this study.
15. Close affiliation with the investigational site (e.g. close relative of investigator),
dependent person (e.g. employee or student of investigational site).;Additional exclusion criteria for healthy volunteers for brain imaging and probable AD patients only
1. Evidence for, history of or imaging findings indicative of any neurological disease (AD patients: other than Alzheimer*s disease, including other dementias) or psychiatric disorder, including e.g. brain surgery, intracranial hematoma, stroke/cerebrovascular disease, epilepsy, inflammatory or infectious disease, severe depression, attempted suicide or current suicidal ideation.
2. MRI brain scan findings that reveal changes indicative of stroke and/or generalized cerebrovascular disease, e.g., the ARWMC scale with a white matter lesion score of >2 and a basal ganglia score of >1.
3. Allen*s test indicative of reductions in arterial perfusion of the hand which would
compromise the perfusion during arterial blood sampling
4. Receiving drug therapy with known significant action on the CNS such as NSAIDs
(within 24 hours), aspirin (within 12 hours), or benzodiazepines, corticosteroids,
vinpocetine, vincamine and other eburnamine derivatives, within 5 half-lives of the
respective drug before radiotracer administration.
5. Subjects in whom magnetic resonance imaging (MRI) is contraindicated or receipt of any contrast material (X-ray, MRI) or radiopharmaceuticals within 48 hours or 5 half lives prior to the application of the radiotracer or if application of such a substance is planned during the observation period.;Additional exclusion criteria for healthy volunteers for brain imaging only
1. Clinical significant abnormal physical examination.
2. Family history of AD in 1st or 2nd degree relative.