On the outside, it looks like every other brain scanner — a hollow metal cylinder with a hard, retractable cot. On the inside, however, the Connectome scanner boasts the most advanced brain imaging technology in the world. Installed at Massachusetts General Hospital in Boston in September 2011, this magnetic resonance imaging (MRI) scanner is poised to be the Hubble Space Telescope of neuroscience.
The scanner, built as part of an $8.5 million federal grant, features a gradient field that is eight times more powerful than a conventional MRI machine. It produces images that are four to eight times more detailed, and does so in one-sixth of the time. The scanner, quiet enough for a baby to sleep inside, relies on a new brain-imaging technique called diffusion MRI, which maps long-distance white matter connections in the brain by tracking the movement of water.
The scanner plays a part in the Human Connectome Project, a five-year effort with National Institutes of Health funding to map every twist and turn of the 86 billion neurons in the human brain. Researchers hope that clarifying the structure of the brain will help us understand its function and dysfunction.
Typically, scanning is done for the purpose of finding lesions in the head, such as for diagnosing a stroke, says Van Wedeen, inventor of one type of diffusion MRI called cross-fiber and director of connectomics at the Athinoula A. Martinos Center for Biomedical Imaging at MGH. Yet evidence suggests that conditions such as post-traumatic stress disorder, autism and dementia involve alterations in white matter. So while the Connectome scanner is currently used only for research purposes, it could someday objectively diagnose mental disorders, he says.