Amyloid PET CT

Amyloid PET CT is an imaging method used to diagnose Alzheimer's disease; it helps visualize beta-amyloid accumulation in the brain.

What Is Amyloid PET CT?

Amyloid PET CT is a nuclear medicine imaging method used to diagnose Alzheimer's disease and detects the presence and distribution of beta-amyloid plaques in the brain. Beta-amyloid plaques are an accumulation of a protein that is a marker of Alzheimer's disease.

In an amyloid PET CT scan, a special radioactive marker that binds to beta-amyloid plaques is administered intravenously to the patient, and then the plaques to which this substance has bound are visualized in the brain.

Amyloid PET CT can detect micro-beta-amyloid accumulations that cannot be detected with classic MRI or CT, and early diagnosis can be achieved. The scan result is reported as "positive" or "negative".

What Is Amyloid PET CT Used For?

The primary purpose of Amyloid PET CT is to detect the presence of beta-amyloid plaques in the brain, as beta-amyloid plaques are a sign of Alzheimer's disease. Amyloid PET CT is performed to detect the following conditions:

• Diagnosis of Alzheimer's or dementia
• Diagnosis of persistent or progressive unexplained mild cognitive impairment
• Assessment of patients diagnosed with Alzheimer's disease but with unexpected symptoms or accompanying medical problems
• Assessment of patients who are asymptomatic or whose symptoms are not confirmed by clinical examination
• To determine the risk of Alzheimer's disease
• Early diagnosis need for patients with a family history of dementia or with the ApoE gene

How Is Amyloid PET CT Performed?

Amyloid PET CT is a non-invasive method and generally involves the following steps:

• Before the procedure, a radioactive tracer that binds to beta-amyloid protein is injected into the patient intravenously.
• It takes approximately 1 hour for the substance to enter the bloodstream.
• After the waiting period, the patient is placed supine on the PET CT device and their head is stabilized.
• The PET scan detects the radiation emitted from the radioactive tracer and creates images of the brain.
• The amyloid PET CT scan takes an average of 15–20 minutes.
• No pain is felt during the procedure.
• The patient must remain still during the scan.
• The images obtained of the amyloid plaques are evaluated by a nuclear medicine specialist and a radiologist.
• After the procedure, the patient can return to their daily life.

Which Patients Undergo Amyloid PET CT?

Amyloid PET CT is not performed on all patients and is preferred in certain patient groups. It is particularly performed on patients experiencing unexplained cognitive decline. It helps in diagnosing dementia cases that are inconsistent with Alzheimer's or have an atypical course. It is also preferred in cases where clinical evaluation, neuropsychological tests, and MRI results are contradictory.

Patients suitable for Amyloid PET CT include:

• Individuals showing signs of memory loss or cognitive decline
• Patients who cannot receive a definitive diagnosis through magnetic resonance imaging (MRI) or clinical examination
• Patients who require greater clarity in diagnosis and treatment planning

How Are Amyloid PET CT Results Interpreted?

Amyloid PET CT results are evaluated as "positive" or "negative". A positive amyloid PET CT result indicates a significant level of beta-amyloid accumulation in the brain. A negative amyloid PET CT result indicates that there is no significant level of beta-amyloid accumulation in the brain. A negative amyloid PET CT result rules out the possibility of Alzheimer's disease.

What Are the Advantages of Amyloid PET CT?

• It enables the early and accurate diagnosis of Alzheimer's and other types of dementia.
• It reduces the risk of misdiagnosis, thus eliminating the need for unnecessary treatment.
• It facilitates the planning of personalized treatment methods.
• It is a clearer source of information about the disease for the physician.

Frequently Asked Questions About Amyloid PET CT

Is Preparation Required Before Amyloid PET CT?

No preparation is required before an amyloid PET CT scan, but mild fasting may be requested. The patient can return to their daily life after the procedure. Comfortable clothing can be worn on the day of the procedure, and metal accessories should be removed. Patients with claustrophobia should inform their physician in advance, and mild sedation may be administered if necessary.

How Is the Medication Administered During an Amyloid PET CT Procedure?

The medication used in an Amyloid PET CT procedure is called a radioactive tracer and is usually injected intravenously into the arm.

Is Amyloid PET CT Harmful?

Amyloid PET CT is generally considered a safe imaging method. There is exposure to a low dose of ionizing radiation during the procedure, but this dose is similar to most CT methods.

What Is the Price of an Amyloid PET CT Scan?

The price of an amyloid PET CT scan varies depending on the hospital, the physician, the radioactive tracer used, and insurance coverage.

What Is the Centiloid Score?

The Centiloid score is a measurement system that indicates the amyloid burden detected in the brain during an amyloid PET scan. The Centiloid scale ranges from 0 to 100. A value of 100 indicates the high amyloid burden typically seen in Alzheimer's patients. A value of 0 indicates the amyloid burden seen in young and healthy individuals.