By Avigayil Kadesh
An Israeli company is using advanced imaging to reveal subtleties about the workings of the human body that will help physicians diagnose diseases earlier, devise personalized treatments and evaluate how those treatments are working.
“This is a unique company in Israel and there are not many like it in the world. Most of our clients are drug developers, medical device companies and academic researchers,” says Efrat Sasson, who co-founded BioImage in Tel Aviv with fellow neuroscientist Tamar Blumenfeld-Katzir in 2009.
“Both of us earned a PhD in the field of MRI [magnetic resonance imaging], and during our studies we realized the need for expertise in imaging. Since we founded BioImage, we have been involved in projects in many areas, among them multiple sclerosis, aging, cognition, oncology, Alzheimer’s disease and cartilage healing.”
"Most people know that getting an MRI means being slid into a big machine that provides high-resolution images of internal organs," says Sasson. “But MRI also can be used like a kaleidoscope, so when you turn it you can receive different images and contrasts that are not only anatomical but quantitative. This is of great value to researchers and pharmaceutical companies to investigate the efficacy of treatments.”
The method is called diffusion MRI, or diffusion tensor imaging (DTI).
In early 2013, the journal Experimental Neurology published research by Sasson and Blumenfeld-Katzir, together with Prof. Ruth Arnon from Weizmann Institute, showing that DTI can reveal the pathology of multiple sclerosis (MS) in the brain, as well as how the Israeli-innovated MS drug Copaxone effects improvement.
In another project, they analyzed before-and-after images in 3D for IceCure, maker of an Israeli device that freezes fibrous breast tumors out of existence. BioImage was able to show the change in the density of the cells after treatment.
Now working with Simona Bar Haim of Ben-Gurion University of the Negev, the BioImage team is scanning the brains of adults with cerebral palsy, and learning how the pictures can help determine what type of physical therapy would be most likely to help each patient.
White matter matters
Sasson explains that advanced imaging makes it possible to photographically reconstruct the neuronal fiber bundles of the brain.
“The brain is like a telephone network,” she explains. “Different functional regions are connected to one another by nerve fibers, allowing communication between them. Electrical signals pass through these fibers like telephone cables, and the fibers are surrounded by a white fatty tissue called myelin that allows faster conduction.”
In people affected by diseases and disorders such as Alzheimer’s, some of the connections are impaired because of inadequate myelin, and the DTI technique illustrates this graphically.
As part of her doctoral studies under Prof. Yaniv Assaf of the Sagol School of Neuroscience at Tel Aviv University, Sasson scanned 52 volunteers, aged 25 to 82, to see how the brain’s fiber tracks correlate with cognitive skills and how aging changes those tracks.
The subjects performed computerized cognitive tests devised by the Israeli company NeuroTrax, as their brains were being scanned at the Tel Aviv Sourasky Medical Center using the advanced methodology. Results were published last March in the journal Frontiers in Brain Imaging Methods.
The images showed interesting correlations: People with denser white matter between their frontal and parietal lobes performed math faster. Those with denser white matter along fibers connecting two language regions of the brain were more quickly able to name the color in which a word for a different color was written (for example, the word “red” printed in blue). Subjects with superior memories were found to have higher fiber density in the area known as the fornix.
“Deterioration with age was found, too, which is not surprising,” says Sasson.
However, an earlier study by Blumenfeld-Katzir, published in a 2011 edition of PLoS ONE, demonstrated it is possible to change the structure of white matter at various ages and improve specific mental functions in lab rats.
“You can improve the brain even in aging,” emphasizes Sasson. “With special learning tasks, we can train the mind and our imaging enables us to see even the little differences it makes.”
DTI has promising implications, Sasson says, for earlier diagnosis of diseases and for efficacy studies to show how tissue improves after treatment. Best of all, it’s not invasive.