Unable to reach the target enrollment of 40 participants with Alzheimer's disease.

This study involves imaging participants' brains using MRI. The goal is to develop a high-resolution, high-sensitivity imaging tool, hyperpolarized xenon functional brain magnetic resonance imaging, which can provide more sensitive measurement of brain function, facilitating the development of drugs for more successful treatment of Alzheimer's disease.

The described study is a pilot study in which the investigators aim to develop an enhanced sensitivity tool for assessment of neural function. Participation involves at least two study visits no longer than three hours in length each. During visit 1, informed consent and screening for eligibility will take place. During visit 2, fMRI scanning will take place in which participants will complete simple tasks. Two types of MRI scans will be performed: traditional proton fMRI and hyperpolarized xenon-129 fMRI (HP 129Xe fMRI) scans. The trade name for xenon-129 hyperpolarized with a Xemed LLC polarizer is NeuroXene.

Participants will be placed in the 3T MRI at the Thunder Bay Regional Research Institute with a Clinical MR Solutions (CMRS) Dual Brain Coil that fits over their head like a helmet. Several inhalation procedures will be performed by participants when breathing NeuroXene from a tube in the scanner. Preparation and administration of NeuroXene and the CMRS Dual Brain Coil will be carried out according to the SOP's developed by the TBRRI and Xemed LLC.

MRI scanning will be performed with a MR Tech and Registered Respiratory Therapist present. Dispensing of 129Xe will be monitored using a gas dispensing form and a drug accountability log. This study will have a monitor assigned to it from the TBRRI that is not involved in this clinical trial. This is to ensure participant safety and adherence to the protocol.

Inclusion Criteria:

A participant is eligible for inclusion in the study if the individual meets all of the following criteria:

1. Self-reported proficiency in English language.
2. Equal to or more than 8 years of education.
3. Normal or corrected to normal vision.
4. Able to provide informed consent.
5. Able to hold their breath for 20 seconds.

Normal cognition for healthy participant group inclusion criteria:

1. Preserved independence in functional abilities.
2. MoCA score no less than 26.
3. Males and non-lactating females of 18 to 85 years of age.

Alzheimer's disease group inclusion criteria:

1. Participants meet National Institute on Aging-Alzheimer's Association for probable or possible Alzheimer's Disease dementia.
2. MoCA score no less than 16.
3. Males and non-lactating females of 60 to 85 years of age.
4. Have a family member, close friend, or LAR that can be present for the informed consent process and study visits.

Exclusion Criteria:

A participant is ineligible for the study if the individual meets any of the following criteria:

1. Serious underlying medical condition, other, then the condition being investigated, which may affect cognitive function of the participant (in the opinion of the investigator): substance abuse, psychotic or depressive disorder, advanced or poorly controlled cardiac, pulmonary, hepatic, renal, neurological disorders in which the patient has significant speech, visual, motor or cognitive deficit, seizure disorders, endocrine or infectious disease or active malignancy.
2. MRI incompatibility as determined by MR Technologist during MRI screening.
3. Self-identifies as claustrophobic.
4. Female exclusion only: Are or may be pregnant; Planning on becoming pregnant.
5. Is a student currently enrolled in a course at Lakehead University where the Principal Investigator (PI) is the instructor.
6. Is a student currently enrolled in a degree program at Lakehead University where the PI is their direct thesis supervisor.
7. Is currently an employee of the PI at the Thunder Bay Regional Research Institute (TBRRI) and/or Lakehead University.

Normal cognition group exclusion criteria:

1. History of diagnosed neurological disease or injury.

Alzheimer's disease group exclusion criteria:

1. Existing diagnosis of dementia of etiology other than Alzheimer's disease.
2. Acute Delirium on the day of scanning (CAM tool assessment)