PET for the diagnosis of Alzheimer's disease

Diagnosis of Alzheimer's disease is often a very difficult task, since a number of other diseases can cause similar symptoms. An international team of researchers led by Professor Oskar Hansson from Lund University (Sweden), has developed a new method of imaging brain tissue to solve this problem. It provides an opportunity to identify deposits of tau protein specific to Alzheimer's disease.

The image obtained using positron emission tomography shows a significant prevalence of tau protein in the temporal and parietal regions of the brain of patients with Alzheimer's disease. Experts know of two proteins associated with Alzheimer's disease: beta-amyloid, which forms plaques in brain tissue, and tau protein, which forms strands inside brain cells.

Beta-amyloid spreads through the brain tissue at an early stage of the disease, long before the patient begins to notice the symptoms of the disease. Tau protein, on the contrary, comes into play later and gradually spreads from the temporal lobes to other regions of the brain. It is then that neurons begin to die and the patient has the first cognitive problems. If the visualization of the brain of a patient with memory disorders shows a large amount of tau protein, the attending physician can diagnose Alzheimer's disease with a high degree of confidence.

The authors proposed to visualize the accumulation of tau protein using positron emission tomography (PET), carried out with the help of radioactive markers moving to different regions of the body. In this case, a special marker based on radioactive fluorine ¹⁸ F is used to detect tau protein.

The results of their study, which involved more than 700 patients, demonstrated a high sensitivity and specificity of the method. With its help, it was possible to identify 90-95% of all cases of Alzheimer's disease, while only a few false positive results were obtained in patients with other diseases.

The method of imaging tau protein using PET has a significantly higher diagnostic efficiency compared to magnetic resonance imaging, and also gives fewer false positive results than the use of PET to detect beta-amyloid. Therefore, as soon as the new method is approved for clinical use, it will need to be most actively used in the examination of patients with memory disorders.

Despite the lack of effective treatments for Alzheimer's disease, correct diagnosis of the disease is extremely important. On the one hand, the patient will be able to receive medications to alleviate symptoms, and on the other hand, physical activity, proper nutrition and the correct dosage of other medications taken by him can help in optimizing cognitive abilities.

In addition, the use of PET to visualize tau protein can be very useful in conducting clinical trials of new drugs for the treatment of Alzheimer's disease, since it can be used to assess the ability of the drug to prevent the spread of pathological protein in brain tissue.

Article by Rik Ossenkoppele et al. The discriminatory accuracy of [¹⁸ F]flortaucipir PET for Alzheimer's disease versus other neurodegenerative disorders is published in the Journal of the American Medical Association.

Evgenia Ryabtseva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of Lund University: New method enables accurate diagnosis of Alzheimer's disease.