Researchers at Stanford University have developed a new method to quantitatively measure human brain tissue using magnetic resonance imaging.
"We're moving from qualitative--saying something is off--to measuring how off it is," Aviv Mezer, a postdoctoral scholar in psychology and a member of the interdisciplinary research team at Stanford, said in an announcement. Their work has been published online in an article in the journal Nature Medicine.
The ability to quantitatively measure the volume of large molecules within each cubic millimeter of the brain, the researchers say, could change the ways in which doctors diagnose and treat neurological diseases like multiple sclerosis.
To date, the problem with taking quantitative measures with MRI has been that they take too long to process, according to Mezer. Brian Wandell, a psychology professor at Stanford, and Mezer have developed a faster scanning technique that while initially inconsistent, has become more reliable, Mezer said.
In MRI imaging, brain images consist of voxels, or three-dimensional elements. According to Mezer, the fraction of each voxel filled with brain tissue is called the macromolecular tissue volume (MTV), and different areas of the draft have different MTVs. Being able to measure and track MTV is useful, Mezer said, since it is "the most basic entity of the structure--it's what the tissue is made of."
The Stanford team used this quantitative approach to analyze a group of multiple sclerosis (MS) patients. In the case of MS, the disease erodes myelin--which comprises most of the volume of the brain's white matter. As the myelin erodes, the MTV of the white matter changes. Mezer and Wandell found that MS patients' white matter tissue volumes were significantly lower than those of healthy volunteers. Now they're following up with the patients to see how they're affected by MS drug therapies by measuring MTV values to track individual brain tissue changes over time.