- Alzheimer’s disease is now diagnosed by the onset and acceleration of symptoms.
- Researchers now say they are hopeful that a new MRI-based brain scan can detect the disease before symptoms appear.
- The scan uses an algorithm to scan 115 regions of the brain.
- Another group of researchers says they are working on another method in which the brain is scanned for regions that aren’t functioning due to the loss of healthy neurons.
The race is on to find new ways to get an early diagnosis of Alzheimer’s disease using easy, noninvasive, low-cost methods.
Some of the most recent research has focused on using magnetic resonance imaging, or MRI, scans of the brain.
Alzheimer’s is usually diagnosed by the onset of symptoms, but by that time the disease is already underway.
Once diagnosed, an MRI scan is able to show brain shrinkage associated with Alzheimer’s. So far, however, an MRI hasn’t been useful in picking up early signs of the disease.
Now scientists say there may be some breakthroughs in getting an early diagnosis using an MRI. One of the latest studies was
A team of researchers from both the United Kingdom and the United States says their predictive model relies on getting an MRI on a standard 1.5 Tesla machine that’s used for routine scans.
They adapted an algorithm used to classify cancer tumors. They divided the brain into 115 regions and allocated different features to each region.
They trained the algorithm to identify where changes to those features could accurately predict the existence of Alzheimer’s disease.
The team tested its approach on brain scans from more than 400 people with early-stage and late-stage Alzheimer’s and other neurological conditions. The researchers also tested it on data from more than 80 people undergoing tests to diagnose Alzheimer’s.
They reported that in 98 percent of cases, their MRI-based machine learning system could accurately predict whether a person had Alzheimer’s-related brain changes.
They said it was also able to distinguish between early-stage and late-stage Alzheimer’s with fairly high accuracy in 79 percent of people.
Healthline asked Rebecca Edelmayer, Ph.D. to weigh in on the research. She is a scientist and senior director of scientific engagement for the Alzheimer’s Association.
“This research is in its early days and it is not ready to be used as a stand alone diagnostic tool,” she told Healthline.
“It is a model that will need more testing in a larger prospectively collected set of data from a diverse group of individuals,” Edelmayer added. “For the model to be effective at predicting Alzheimer’s and other dementia, it will need to be generalizable to the broader Alzheimer’s population.”
Edenmayer also noted that the diagnostic model was developed for a specific type of MRI machine with a particular strength of magnetic field.
She said with a variety of machines in use, the results can’t be generalized to all types of scanners. But she said the research is working to address an important issue in the field — early detection.
“With FDA [Food and Drug Administration] accelerated approval of the first anti-amyloid disease-modifying Alzheimer’s treatment and more coming down the pipeline, it is vital that individuals with Alzheimer’s be diagnosed early in the disease process when treatment may be most beneficial,” she explained. “Plus, early detection of Alzheimer’s allows individuals and their families more time to plan for the future, participate in clinical trials and seek community resources.”
“There is a lot of research going in this direction to try to use MRI or some other kinds of technology to detect early onset of Alzheimer’s,” said Dmitriy Yablonskiy, Ph.D., a professor of radiology at the Mallinckrodt Institute of Radiology at the Washington University School of Medicine in St. Louis.
Yablonskiy and his colleagues say they have a “novel MRI approach” that could be a way to identify brain cell damage in people in the early stages of Alzheimer’s before brain shrinkage is visible and before they have cognitive symptoms.
“It is easy to implement on commercial MRI scanners and it takes six minutes to get this information,” he told Healthline.
The researchers published their study results in the Journal of Alzheimer’s Disease three months ago.
Their approach involves a new quantitative Gradient Echo (qGRE) MRI technique developed in the Yablonskiy lab to show brain areas that are no longer functioning because of a loss of healthy neurons. Using the qGRE technique, those areas where the neurons were starting to degenerate appeared as so-called “dark matter.”
Without using that technique, they would appear normal on the MRI.
The research team studied 70 people, ages 60 to 90. They included people with no cognitive impairment as well as those with very mild, mild or moderate impairment.
Researchers applied their qGRE MRI technique to scan the hippocampus, the brain’s memory center and one of the earliest regions affected in Alzheimer’s. Their results showed that, in some participants, the region often contained a healthy tissue section with relatively preserved neurons and a “dark matter” dead zone without healthy neurons.
Those “dark matter” zones showed up in people who tested positive for amyloid but were not yet experiencing symptoms.
Yablonskiy says next his team will set out to validate its findings with a larger study group. He believes their technique could be widely used to get an early Alzheimer’s diagnosis.
“I’m really excited about this, yes absolutely,” he said. “Not just me, but the whole team here.”