Washington, June 24 : Physicians would now be able to accurately detect Alzheimer's disease at an earlier stage- thanks to an automated system for measuring brain tissue with magnetic resonance imaging (MRI), a new study has revealed.
Alzheimer's disease is characterised by nerve cell death and tissue loss leading to shrink of all areas of the brain, especially the hippocampus region.
And now, radiologists would be able to visualize subtle anatomic changes in the brain that signal atrophy, or shrinkage with the help of MRI with high spatial resolution. However, the standard practice for measuring brain tissue volume with MRI, called segmentation, is a complicated, lengthy process.
"Visually evaluating the atrophy of the hippocampus is not only difficult and prone to subjectivity, it is time-consuming. As a result, it hasn't become part of clinical routine," explained the study's lead author, Olivier Colliot, Ph.D, from the Cognitive Neuroscience and Brain Imaging Laboratory in Paris, France.
For the study, the researchers used an automated segmentation process with computer software developed in their laboratory for measuring the volume of the hippocampus in 25 patients with Alzheimer's disease, 24 patients with mild cognitive impairment and 25 healthy older adults.
Later, these MRI volume measurements were compared with those reported in studies of similar patient groups using the visual, or manual, segmentation method.
A significant reduction in hippocampal volume was found in both the Alzheimer's and cognitively impaired patients when compared to the healthy adults. Alzheimer's patients and those with mild cognitive impairment had an average volume loss in the hippocampus of 32 percent and 19 percent, respectively. Studies using manual segmentation methods have reported similar results.
"The performance of automated segmentation is not only similar to that of the manual method, it is much faster. It can be performed within a few minutes versus an hour," said Colliot.
The Alzheimer's Association said that one of the goals of modern neuroimaging is to help in the early and accurate diagnosis of Alzheimer's disease, which can be challenging. When the disease is diagnosed early, drug treatment can help improve or stabilize patient symptoms.
"Combined with other clinical and neurospychological evaluations, automated segmentation of the hippocampus on MR images can contribute to a more accurate diagnosis of Alzheimer's disease," said Colliot.
The study is published in the upcoming issue of the journal Radiology.