Radiologists in Switzerland and the Netherlands say an MRI without a contrast agent was enough to detect a telltale biomarker in the brain for Alzheimer's disease. The Los Angeles Times reported that the study used an imaging technique known as arterial spin labeling to detect low blood flow in the brain's posterior cingulate cortex. This biomarker predicts mental decline 18 months after, according to the story. Researchers recruited 148 patients for their research who, when the trial began, had no dementia. After 18 months, almost half had "deteriorating cognitive function." Patients who showed no decline in cognitive function had normal blood flow in the posterior cingulate cortex, but it was lower in patients who had even mild cognitive decline prior to "deteriorating cognitive function." While more research is needed, the hope is that the diagnostic technique could help spot patients at highest risk for developing Alzheimer's so doctors can intervene sooner for treatment, according to the story. Details are published in the journal Radiology. Story