The newer 7T machines however get images down to a microscopic level. In human blood there are hydrogen atoms in the water molecules it contains. When they are placed in a strong magnetic field, they align with the field, in a sense acting like a magnet. Radio waves produced by the scanner excite these hydrogen atoms causing them to spin Once they stop twirling, they emit specific signals that are detected by the scanner and processed by computers to produce an image. With the 7T scanners, even the tiniest fluctuations in blood flow in the brain and other metabolic changes are picked up and this makes the images much more helpful to doctors.
Another advance in brain imaging comes from taking MRI images and images from Diffuse Tensor Imaging scans, which track the movement of water molecules through the brain’s fibrous stuctures, and creating a 3D holographic image of the network of fibers in the brain. Being able to visualize these structures is important for evaluating patients who may have Alzheimer’s or other forms of dementia. The British company Holoxica has created a prototype of the technology and hopes to have it in production soon. The CEO Dr. Javid Khan said in a press release, “A recent study concluded that 3D visualisation is up to 75 per cent better than 2D for certain types of tasks including spatial manipulation, finding, identifying or classifying objects, but our future plan is to take 3D imaging to the next level using our holographic video display, which is being designed for medical imaging machines including MRI, CT and Ultrasound scanners.” The video below explains these two kinds of imaging and what they mean for neuroscience.
Sources: Holoxica, The Daily Record, Siemens