It only takes a smidgeon of emotion to make the heart rate accelerate… It is proof of how our feelings can influence our cardiac muscle. But it is also true that while blood is being pumped around our body, the brain is affected too, and we don’t just mean because of our mood changes, but because of our brain structure.
These cerebral motions are tiny. Almost unnoticeable, no more than 10 to 15 micrometres of magnitude, which is barely the diameter of a human hair. And yet, a new technique of brain imagery means researchers can now expand and magnify these tiny movements straight onto recorded images. It’s called aMRI or ‘phase-based amplified MRI’.
This imaging method using magnetic resonance is the product of work done by a team of researchers from the University of Stanford and the Institute of Stevens Technology, in New Jersey – both in the United States, as well as a team from the University of Auckland, in New Zealand, who have just published a study in the Magnetic Resonance in Medicine journal.
A unique technique
Thanks to their joined efforts, scientists have managed to develop a new device, combining the effects of an MRI machine with a pulsometer, a device capable of measuring the number of arterial pulses. Using an algorithm, information from the cardiac rhythm provided by the pulsometer were then synchronised with the cerebral images.
The researcher’s goal was to be able to ‘magnify’ in real-time videos each of these micro-movements that appear in the brain when blood is being pumped around the body. And the very least we can say is that scientists really have risen to the challenge, as one of the co-authors of the study, Itamar Terem, from the University of Standford says.
We have succeeded in revealing small motions near the midbrain [or mesencephalon], spinal cord, cerebellum and even in areas such as the frontal lobe.
A clever algorithm
To come to this ground-breaking result, the algorithm specifically targets these rather precise areas of the brain. The treatment applied to images records the shape of the brain as well as all anatomical characteristics. The movement of cerebral tissue, the blood flow and the cerebrospinal fluid, for their part, are exaggerated in order to reveal the subtlety in the recorded images.
Besides these slight yet noticeable movements, another even more subtle motion has been recorded and revealed in other regions of thebrain that were previously unknown about. Samantha Holdsworth a co-developer of the technique from the University of Auckland stated:
You can sometimes capture the whole head ‘nodding’ in the scanner due to the force of the blood pumping into the brain every time the heart beats.
In order to prove what this new imaging technique can do, researchers have tested it on two patients, one who was healthy, and another who was suffering from Arnold-Chiari, a congenital rare cerebellum malformation, particularly caused by intracranial hypertension and neurological disorders.
New perspectives for neurological medicine
For the patient suffering from this condition, the technique was able to record more significant cerebral movements than in the healthy patient, which marks the first step towards a more efficient treatment for the condition. Mehmet Kurt, from the Steven’s Institute of Technology, explained:
Better visualisation and understanding of the biomechanical properties of the brain could lead to earlier detection and monitoring of brain disorders.
After these first steps of conclusive tests, researchers now plan to take advantage of their technique to study other conditions such as aneurysms, hydrocephalus, or even brain concussions. This seems to be a new era for neurology.