Current diagnosis of Alzheimer’s relies largely on documenting mental decline. Individuals who are diagnosed in this manner have already suffered severe brain damage. Neuroimaging is among the most promising areas of research focused on early detection. Today, a standard screening for Alzheimer’s includes structural imaging with magnetic resonance imaging (MRI) or computed tomography (CT). These tests are used to screen for diseases similar to Alzheimer’s that require different treatment methods. Structural imaging can reveal tumors, head trauma, or strokes.
Recently, the U.S. Food and Drug Administration approved the first molecular tracer for use of patients being evaluated for Alzheimer’s disease. This tracer is radioactive allowing it to be seen during a positron emission tomography (PET) brain scan, broadening the scope of treatment.
A task force of the Society of Nuclear Medicine and Molecular Imaging (SNMMI) and the Alzheimer’s Association recently published criteria dictating when certain diagnostic imaging procedures for Alzheimer’s evaluation was appropriate.
Structural Imaging
Structural imaging studies have revealed that the brains of people with Alzheimer’s shrink significantly as the disease progresses. Research has increasingly determined that shrinkage of specific areas of the brain – such as the hippocampus, may be an early sign of Alzheimer’s. However, scientists have yet to agree on standardized values for brain volume that would establish the significance of a specific degree of shrinkage for anyone person.
Functional Imaging
Functional imaging research with positron emission tomography (PET) and other methods suggest that people with Alzheimer’s have less brain activity in certain areas. Alzheimer’s often parallels deficiencies of glucose in areas known for processing memory, learning and executive function. However promising these studies may be, research is still in its nascent stages and no conclusive patterns can be established for diagnostic information about individuals.
Molecular Imaging Technologies
Molecular imaging technologies are on the forefront of new approaches to diagnose Alzheimer’s in its earliest stages. Molecular diagnostics may be able to detect biological cues long before the disease causes permanent damage to the brain’s structure or function. Molecular imaging offers a new strategy for monitoring disease progression and assess next-generation disease treatments.
Fortunately, the strengths and weakness of available imaging technologies are complementary. This has led to multi-modal imaging studies in which several techniques are simultaneously or sequentially applied to the same subjects for the same period of time. The value of any imaging technology will be determined by its efficacy in finding and implementing therapies. The value is inclusive of contributions to diagnosis. Because imaging technology’s most effective use in the treatment of Alzheimer’s has been early-stage evaluation, there has been an interest in “prevention” studies. Research is being done to see whether therapies are having a disease-modifying effect that could potentially translate into a delay in clinical onset.
For more information on, or to set up an appointment with The Center for Diagnostic Imaging, call 1-800-371-0002.
 "June is Alzheimer’s Awareness Month."){kind=logo}
