Arterial spin labeling technique uses MRI to diagnose Alzheimer's

Researchers from the Perelman School of Medicine at the University of Pennsylvania (Philadelphia, PA, USA) are using a magnetic resonance imaging (MRI) technique called arterial spin labeling (ASL) to diagnose Alzheimer's disease.

Researchers from the Perelman School of Medicine at the University of Pennsylvania (Philadelphia, PA, USA) are using a magnetic resonance imaging (MRI) technique called arterial spin labeling (ASL) to diagnose Alzheimer's disease.

The team has determined that the ASL-MRI test is a promising alternative to the current standard -- a specific positron emission tomography (PET) scan that requires exposure to small amounts of a radioactive glucose analog and costs approximately four times more than an ASL-MRI.

In brain tissue, regional blood flow is tightly coupled to regional glucose consumption. Increases or decreases in brain function are accompanied by changes in both blood flow and glucose metabolism.

ASL-MRI can be used to measure neurodegenerative changes in a similar way that fluorodeoxyglucose positron emission tomography (FDG-PET) scans are used to measure glucose metabolism in the brain. Both tests correlate with cognitive decline in patients with Alzheimer's disease.

Dr. John Detre, a professor of neurology and radiology at the university, said that the ASL-MRI test had been designed to allow cerebral blood flow to be imaged noninvasively and quantitatively using a routine MRI scanner.

When Alzheimer's disease is suspected, patients typically receive an MRI initially to look for structural changes that could indicate other medical causes, such as a stroke or brain tumor.

Adding about 10-20 minutes to the test time, ASL can be incorporated into the routine MRI and capture functional measures to detect Alzheimer's disease upfront, turning a routine clinical test (structural MRI) into both a structural and functional test.

Given that ASL-MRI is entirely noninvasive, has no radiation exposure, is widely available and easily incorporated into standard MRI routines, it is potentially more suitable for screening than FDG-PET scans.

-- By Dave Wilson, Senior Editor, Vision Systems Design

More in Home