Edwin L. Aguirre
It starts out as memory loss — forgetting names, places, dates or phone numbers and misplacing things. Most people tend to dismiss such lapses as normal aging, but as Alzheimer’s disease progresses, the symptoms can include confusion and increasing difficulty in communicating, working or organizing. Eventually, patients in late stages of the disease require round-the-clock care.
According to the Alzheimer’s Association, there are 5.4 million Americans living with the disease today, including an estimated 200,000 under the age of 65. By 2050, up to 16 million will have Alzheimer’s. While treatments for managing symptoms are available, there is currently no known cure for Alzheimer’s. Researchers around the world are working to change that with projects targeting improved prevention, diagnosis and treatment.
Among the investigators involved Alzheimer’s research is Asst. Prof. Joyita Dutta
of the Department of Electrical and Computer Engineering
, who leads the Biomedical Imaging and Data Sciences Laboratory at UMass Lowell. Her lab is involved in developing novel image- and data-processing tools that merge traditional signal processing with the emerging field of data science.
“My goal is to develop imaging-based biomarkers, measurable substances in the patient’s brain whose presence are indicative of Alzheimer’s disease,” says Dutta, who is also a radiology instructor at Harvard Medical School and assistant in physics at Massachusetts General Hospital.
The hallmark indicators for Alzheimer’s are two types of abnormal proteins that aggregate in the brain: beta-amyloid plaques and tau tangles, both of which appear many years before the onset of any symptom, Dutta says. The plaques build up in the spaces between the brain’s nerve cells, called neurons, disrupting communication between cells. Tangles, on the other hand, accumulate inside the cells, damaging and killing them.
“If we can develop biomarkers that precisely quantify these abnormal proteins in living patients through imaging, we can help doctors diagnose Alzheimer’s in its early stages, allowing them to accurately monitor the progression of the disease and develop disease-modifying therapies such as anti-amyloid and anti-tau treatments,” explains Dutta.
A Pivotal Role in Research and the Clinic
According to Dutta, tau tangles are known to have a strong connection with neurological degeneration and cognitive deficiencies in the brain. In recent years, new injectable radioactive drugs called “radiotracers” have been developed for positron emission tomography (PET) that can help visualize tau tangles in living patients. PET is an imaging technique that tells physicians how the tissues and organs are functioning. In this case, a radiotracer called “fluorine-18” collects in brain tissues with higher levels of chemical activity, which usually correspond to the diseased areas. On a PET scan, these show up as bright spots or regions.
“My research aims to develop computational methods for generating high-resolution images of tau tangles and studying the spatial distribution and connectivity patterns of these abnormal proteins,” explains Dutta. “By using information from high-resolution MRI [magnetic resonance imaging] scans of the brain, I am able to enhance the resolution of PET images of tau tangles to a level that enables us to measure tau accumulation in small brain structures, which is vital in Alzheimer’s research.”
Dutta says that by acquiring time-series images and modeling the rates of biochemical reactions of the radiotracer, she is able to derive measurements of tau that are far more accurate than what a traditional static PET image provides.
She adds: “I am using high-resolution tau imaging to understand the relationship between the tau connectivity networks and the structural network of the brain, the latter being based on the actual physical connections between neurons. These will yield new tau-based biomarkers for Alzheimer’s, which are expected to play a pivotal role both in research and in the clinic.”
Dutta’s research is supported by a five-year, $603,000 grant from the National Institute on Aging. She is collaborating with Massachusetts General Hospital and Harvard Medical School on the project.