Exploring the Depths of Memory: Unlocking Dementia with Brain PET Imaging (Florbetaben)
Update Date：2025/02/07，
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Department of Nuclear Medicine, Dr. Yu-Shan Wang / Dr. Li-Fan Lin
Frequent Brain Lags? Beware of Dementia Warning Signs
Memory decline and cognitive impairment—such as frequently forgetting things, missing dates, or forgetting names—are not always just a result of aging; they could be signs of dementia. Dementia is a collective term for a variety of symptoms and diseases. According to the 2024 survey conducted by the Ministry of Health and Welfare, the prevalence of dementia among individuals aged 65 and older in Taiwan is about 7.99%. The causes of dementia can be categorized as degenerative dementia (70%), vascular dementia (20%), and other factors (10%).
Among degenerative dementias, Alzheimer's disease (AD) is the most common, and its early symptoms include memory loss, difficulty with speech, and confusion about time and place. Physicians assess potential dementia using clinical symptoms such as memory loss, language difficulties, and disorientation, along with dementia cognitive scales.
Recent research has shown that amyloid plaques (a form of protein deposit) are the earliest pathological features in Alzheimer’s disease. Therefore, early use of diagnostic imaging to detect amyloid plaque accumulation in the brain could significantly aid in identifying potential causes of the disease and guide future treatment strategies.
Imaging Assistance: Making Amyloid Plaques Visible
With the advancement of nuclear medicine, Amyloid PET (Positron Emission Tomography) has become an important imaging tool for diagnosing dementia. Currently, the FDA-approved PET tracers such as F-18-Florbetaben, F-18-Flutemetamol, and F-18-Florbetapir are all radiolabeled with the F-18 isotope.
After intravenous injection, these tracers cross the blood-brain barrier and bind to beta-amyloid plaques in the brain. Using PET scanning, the distribution of these plaques in the brain can be clearly visualized. Amyloid PET is highly accurate, with current studies showing a sensitivity of 96-98%, making it a critical tool in diagnosing Alzheimer's disease and other forms of dementia.
Amyloid PET is suitable for:
1. Patients with atypical clinical presentations of dementia.
2. Patients with mild cognitive impairment of unknown cause.
3. Patients under the age of 65 who present with suspected early-onset dementia.
This non-invasive test provides clear imaging data, making it a powerful tool for early diagnosis even before symptoms manifest. However, it is not currently covered by national health insurance, and patients are required to bear the cost of the test themselves.
As people age, it's possible for small amounts of amyloid protein to accumulate in the brain, even in healthy individuals. Therefore, the imaging results need to be compared with those of healthy individuals and typical Alzheimer's disease patients. A positive result indicates significant amyloid protein accumulation in the brain; however, the clinical symptoms still vary from person to person. A negative result suggests a lower likelihood of Alzheimer's disease, and further investigations should be conducted to identify other potential causes of dementia symptoms.
Before the examination, the patient can eat normally but should avoid wearing metal jewelry. If the patient is pregnant, breastfeeding, or allergic to any medications, they should inform the healthcare provider in advance. After the drug injection, the patient needs to wait for 70-90 minutes to allow the medication to enter the brain and bind to the amyloid protein. The scanning process takes about 20 minutes, during which the patient lies flat on the examination bed and breathes normally. The medication is primarily eliminated through the urinary system, and drinking water can help speed up its excretion. Since the radiation dose is extremely low, there is no risk to the patient or their family. After the examination, the patient can return home and rest.
In recent years, the U.S. FDA has approved several treatments for Alzheimer's disease. Amyloid PET imaging has brought a new breakthrough in diagnosing Alzheimer's disease by non-invasively detecting amyloid protein deposition in the brain, allowing for early diagnosis and assisting in assessing whether a patient is suitable for related drug treatments. If you or your loved ones have any concerns, it is recommended to consult a professional physician early to determine if this examination is appropriate.
