When speaking of the potential of medical technology, there is still a tendency to think in linear terms. For example, physicians will talk about faster and smaller CTs, which use less x-ray energy to image the human body. This is a legitimate way of thinking, because it is consistent with the general experience with consumer oriented devices and services. Everyone expects their cell phone to become more capable and thinner year after year. Everyone expects Wi-Fi access to be more widespread year after year. So, it is fair for physicians to think of the future in terms of present day technologies, but smaller and faster.
A recent article that appeared in the journal Nature, speaks of early development with visible light, which apparently can be used to image “hidden” items as well. Before I discuss this visible light approach to medical imaging, let me take a moment to quickly review the concept behind using x-rays for internal organ imaging.
The concept behind using x-rays is very simple. X-rays are also a form of light, but such a form that is not seen by our human eyes. For our eyes to see something, energy has to stimulate special sensory cells in the back of our eyeballs. This collection of sensory cells is called the retina. X-rays do not stimulate these sensory cells and as such, we cannot see them.
The usefulness of x-rays lies in the fact that they are powerful enough to penetrate our bodies but are still affected by our internal structures. With a plain x-ray, the kind that is done after you have injured a hand and the doctor wants to rule out a fracture, the x-ray beam is focused at the injured area and an impression of the bones is recorded on film that is placed behind the bones. If this sounds similar to the way a regular film camera works, that is because it is.
When a plain x-ray is produced by this method, a person’s bones, which reflect more x-rays than internal organs like the liver, appear white. Once again, this is similar to the way regular film cameras used to work. An object that would reflect all visible light, would appear white. These days, x-rays are digital, and regular film is no longer used [in, at least, the Western world]. But the concept is still the same.
CT machines are in fact glorified regular x-ray machines. They do not use film [chemical or digital], but instead have specialized sensors that read the x-rays after they pass through the human body. This approach, along with a lot of brilliant math, makes it possible for a CT machine to produce the amazing realistic images that it does.
There is one problem with x-ray-based systems, and it is a significant problem. As x-rays pass through the human body, they affect the organs they pass through. Imagine thousands of ping-pong balls being thrown at a person at high speed. afterwards, you would likely see some bruising on the person’s body. In the same way, x-rays “bruise” a person’s internal structures. The huge debate is now whether this amount of damage is easily repaired by the body or if it leaves persistent cellular injury that over time, could even manifest as a disease like cancer. This is not a reason to stop doing CTs, because the information they provide is critical to healthcare and the risk is still considered small, but it does leave the door open for looking for options.
This brings me back to the discussion of using visible light instead of x-rays. Visible light is of much less energy than x-rays and thus does not cause the damage that x-rays do. It was, however, always assumed that visible light could never penetrate the human body and thus could never image internal organs. But based on this recent research, it does appear to be that visible light can pass through things like paint and human tissue and thus could be the basis of a future imaging device that is totally safe.
Turning this research into an actual device will take years if not longer. But the key is that in 20 years from now, CTs may be replaced by such a new imaging system, or by another imaging approach that no one has even thought of yet.
This is the critical element which is missing when most people speak about the future of medicine. It is not just about improving what we have now. It is about a total change in our approach to healthcare. In 20 years from now, the practice of medicine could be so different that present-day physicians will need to be effectively retrained.
In 20 years from now, it might very well be that everyone has a safe and inexpensive full body scanner in their home, which checks our state of health on a daily basis. It could be that within two decades, the idea of going to the hospital for anything other than major surgery, will seem totally antiquated.
As I have said in previous blog posts, it is effectively impossible to predict the path of technology beyond a couple of years into the future. Physicians must begin to be trained to be flexible and to constantly self update. There is simply no way to be an effective physician in this day and age without constant knowledge and skill-set updates. And this will be more and more true as every year passes.
I personally am very excited by all of this potential. Ultimately, it will be the average person in the community who will benefit from all of these advances. I have no idea how such future technology will affect reimbursements and doctors’ salaries and status in the community. Considering that every physician ultimately wants what is best for the patients, none of these side issues should be of concern. As long as patients are kept safer and healthier, medicine is doing its job. And whatever role present-day physicians will play in this future reality, it should be welcomed..
Thanks for listening