If a picture is worth a thousand words, an image is worth a thousand measurements. Imaging offers information on a scale that completely changes what we are capable of learning, and thus what we are capable of doing. Medical imaging has seen an amazing level of innovation and growth, and 2012 has continued this trend. Some of these advances change what we know about the human body and how it works. Others have changed how we approach clinical challenges and study a body that doesn’t work quite right. All of them combine to create a field of medical imaging that allows us to visualize the inner workings of our bodies in new and important ways.
Consider, for example, the work done in imaging patients suspected of having Alzheimer’s Disease. As the brain works, it consumes energy. The gas keeping our cerebral cars running comes in the form of glucose, which we can measure with an imaging study called a FDG-PET scan. Studies have shown that the brains of patients with Alzheimer’s Disease indeed are starting to slow down (i.e., consume less glucose). However, learning this requires injecting an expensive radioactive tracer which isn’t commonly available in many locations due to the technical difficulties associated with actually manufacturing and delivering it. Instead, there has been recent work showing that it may be possible to forego imaging glucose directly, and instead image blood flow (which then transports glucose) as an alternative. The advantage here is that this technique uses widely available and non-invasive MRI equipment, doesn’t expose anyone to harmful radiation, and can be significantly less expensive while yielding very similar results. As brain activity begins to slow, so too does blood flow begin to decrease. Interestingly, we should recognize that this is the application of an existing technique in a new way that has clear and definite benefits to patient care.
Similarly, imaging has taken advantage of advances made in computer engineering and mathematics to lay the groundwork to revolutionize how we will be acquiring images in the near future. One example is the application of “compressed sensing” techniques to image reconstruction. Compressed sensing makes use of redundant information in images to reduce the number of measurements that actually have to be made for any given exam. Much like the way you can reconstruct an entire Sudoku puzzle, given only a few of the numbers, we can reconstruct entire images given a relatively small number of measurements. The result is shorter imaging studies, higher quality images, and fewer demands placed on patients. This is already being realized in the research imaging context, and will certainly play a role in clinical imaging at some point in the future.
In summary, the field of imaging has seen a great deal of innovation and advancement over the course of the last year. While the forms these advances take may change, they all come back to the goal of improving patients’ lives. 2012 has seen many steps in that direction, and I have no doubt we will be able to see more going forward.
Allen T. Newton is Senior Imaging Research Specialist at Vanderbilt University.
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