The prediction of Alzheimer by MRI is better than the current tests

Although there is currently no cure for Alzheimer's disease (AD) and few drugs have been clinically effective in slowing progression, early detection remains a priority for proper management of the disease. . Now, a new study by researchers at the Washington University Medical School's Mallinckrodt Radiology Institute (WUSM) found that brain MRI scans were more effective than clinical trials to predict which patients would develop Alzheimer's disease. disease – a disease that affects 5.5 million Americans. The results of this new study were recently presented at the annual meeting of the North American Radiological Society (RSNA) as part of a presentation titled "Parcel-based Spatial Statistics in People Who Develop Dementia." of Alzheimer's: a study of the Neuroimaging Initiative of Alzheimer's Disease (ADNI) ". ). "

"Alzheimer's disease is the most common cause of dementia in the world and is expected to increase globally, especially in the United States, as the population ages," said the researcher. Chief Cyrus Raji, MD, Ph.D., assistant professor of radiology at the Mallinckrodt Radiology Institute at WUSM. "As we develop new drug therapies and study them during clinical trials, we need to identify the people who will benefit from these drugs earlier during the course of the disease."

Current predictive models, such as standardized questionnaires used to measure cognition and testing of the APOE4 gene, a variant of the gene associated with a higher risk of AD, have limitations and, with precision rates of 1 to 4%. order of 70 to 71%, do not identify many people develop the disease. However, in recent years, researchers have opted for brain MRI using diffusion tensor imaging (DIT), a promising option for analyzing the risk of dementia. These exams evaluate the state of the white matter of the brain.

"With DTI, you observe the movement of water molecules along the white matter pathways, the telephone cables of the brain," said Dr. Raji. "When these pathways are not well connected, cognitive problems can result."

DTI provides different measures of white matter integrity, including fractional anisotropy (AF), a measure of how water molecules move along the white matter pathways. A higher FA value indicates that the water is moving more neatly along the pathways, while a low value means that the pathways are probably damaged.

In the present study, the researchers sought to quantify the differences in ITDs in people with normal cognitive decline or mild cognitive impairment to Alzheimer's dementia compared with controls not developing dementia. They performed brain DTI exams on 61 people from the Alzheimer's Disease Neuroimaging Initiative, a large-scale, multi-site study of disease progression.

About half of the patients developed Alzheimer's disease and DTI identified quantifiable differences in the brains of these patients. People who developed the disease had less FA, compared to those who did not, suggesting white matter lesions. They also had statistically significant reductions in some leaflets of the frontal white matter.

"The DTI performed very well compared to other clinical measures," noted Dr. Raji. "By using the values ​​of AF and other global measures associated with the integrity of the white matter, we were able to obtain an accuracy of 89% to predict who would develop Alzheimer's disease. The mini mental status exam and the APOE4 gene test have accuracy rates of about 70 to 71%. "

The research team was enthusiastic about their results, but understood that more work needed to be done before the approach was ready for routine clinical use. The findings suggest a future role for DTI in diagnosing people at risk for AD. Since many people have already benefited from an MRI as part of their care, the DTI could therefore bring significant added value to the examination without significantly increasing costs.

"Research shows that the risk of Alzheimer's disease can be reduced by tackling modifiable risk factors such as obesity and diabetes," Dr. Raji concluded. "With early detection, we can implement lifestyle interventions and engage volunteers early in drug trials."