Machine learning is a type of artificial intelligence that allows computer programs to learn when exposed to new data without being programmed.
Now, researchers in The Netherlands have coupled machine learning methods with a particular MRI technique that measures the perfusion, or tissue absorption rate, of blood throughout the brain to detect early forms of dementia, such as mild cognitive impairment, according to a new study published online in the journal Radiology.
“MRI can help with the diagnosis of Alzheimer’s disease,” said principal investigator Alle Meije Wink, Ph.D., from the VU University Medical Centre in Amsterdam.
“However, the early diagnosis of Alzheimer’s disease is problematic.”
Scientists have long known that Alzheimer’s disease is a gradual process and that the brain undergoes functional changes before the structural changes associated with the disease show up on imaging results.
Physicians have no definitive way of identifying who has early dementia or which cases of mild cognitive impairment will progress to Alzheimer’s disease.
“With standard diagnostic MRI, we can see advanced Alzheimer’s disease, such as atrophy of the hippocampus,” Dr. Meije Wink said.
The automated machine learning program is taught to recognize patterns in these maps to distinguish among patients with varying levels of cognitive impairment and predict the stage of Alzheimer’s disease in new cases.
The study group included 100 patients diagnosed with probable Alzheimer’s disease, 60 patients with mild cognitive impairment and 100 patients with a subjective cognitive decline and 26 healthy controls.
The automated system was able to distinguish adequately among participants with Alzheimer’s disease, MCI, and SCD. Using classifiers based on the automated machine learning training, the researchers were then able to predict the Alzheimer’s diagnosis or progression of single patients with a high degree of accuracy, ranging from 82 percent to 90 percent.
“ASL is a promising alternative functional biomarker for the early diagnosis of Alzheimer’s disease,” Dr. Meije Wink said.
“ASL-MRI can identify brain changes that appear early in the disease process when there’s a window of opportunity for intervention,” Dr. Meije Wink said.
“If the disease process from SCD to MCI to Alzheimer’s disease could be intercepted or slowed, this technique could play a role in screening.”