My Research - Detecting Cancer with Positron Emission Tomography

Hi Readers,

I periodically have these blogging sprees like today. It's too bad they don't come more often than they do. Right now, many of you probably know that I am at Stanford University, en route to getting a Ph.D in electrical engineering. However, I don't think I've ever talked about what kind of research I do there.

Like the title suggests, I work in a group  that focuses primarily on a medical imaging method called Positron Emission Tomography (PET). It is a technique commonly used for "functional imaging", which means that you are trying to image a process in the body, instead of the structure of the body. Most conventional imaging, such as CT scans (shooting x-rays through the body), MRIs (using magnetic fields to induce proton rotation in the body), and ultrasounds (bouncing sound waves through the body), use structural imaging to accomplish their task.

Here's a simple explanation of how PET works for cancer imaging. Cancer tumors are simply clumps of cells whose only orders are to grow as fast as they can, and forget about what they were originally supposed to do. To grow, they must have as much sugar as possible, and so they gobble up all the sugars in the body to maximize their growth rate. Therefore, if we can attach some kind of tracking device to sugar, we should be able to see where the tumors are by seeing where the sugars go. This is exactly how PET works.

In the case of PET, the "tracking device" is actually a positron that the specialized sugar (called FDG) releases in the body. When the positron is released, it will hit an electron in the body; since one is matter and one is antimatter, they will disappear into pure energy (called annhilation). In this case, the pure energy is released as two photons, or light particles, which shoot out of the location of annihilation in the complete opposite direction of each other. As these two leave the body, they hit detectors that surround the body, which records down their location. After that, you simply draw a line between these 2 locations (like connect the dot), and now you have a line which shows the possible places the tumor is located. These lines go in every random direction and share only one common trait, which is that they must intersect the tumor somewhere. Therefore, if you draw a million lines, the place where they all cross each other is the place where the tumor is located.

The project that I am working on involves the construction of a PET machine that can be used specifically for breast cancer imaging. There are five members on the project team. I am the person in charge of designing and integrating hardware to monitor the operation of the machine. This involves prototyping different configurations of the signal lines on the machine, sensors for temperature and humidity, as well as the detector-by-detector monitoring. Of course, it involves more than that, and probably has much more in common with an industry job than a university Ph.D, but it is a fulfilling and exciting role on a team of brilliant people.

Till next post!
FCDH

Journeying through Time

Hi Readers,

As one of my friends had his wedding this week in Chicago (congrats to SF and RZ!), I decided to take the entire week off to catch up with friends in the Chicago area. I flew into Sioux Falls, South Dakota, to meet up with one of my best friends, SB. We planned on taking a roadtrip through South Dakota and western Nebraska, before driving back to Chicago for the wedding. We saw a bunch of national parks and monuments and did cool things, including the minuteman missile silos, Mt. Rushmore, caving in the Black Hills, driving through herds of buffalo in Custer state park, and hiking at Scottsbluff. After I returned to Chicago, I attended the wedding with another one of my best friends, LB. We proceeded to hang out for the rest of the weekend. I am writing this post from the flight back to SF right now.

Hanging out with these friends, it is hard to believe that 2 years have already passed since I graduated from undergrad. It seems almost as if nothing has changed, and that I am in undergrad again. Time seems to be accelerating. Already, half of my twenties are gone. SB is moving to Canada, and LB may soon become engaged. As much as I would like to think that time is static and that I can continue doing what I've been doing, the reality is that I'm getting old and cannot keep doing this for much longer.

With every year that passes, time becomes more and more valuable. People say that the twenties are the golden years, a time to take risks, have fun, and be reckless. The twenties are the time when people are the most flexible with their life options. That should make it the golden time to try new things. Some people think the only thing worth trying out in the twenties are different people, but that is only one aspect of life. But it is easy to get stuck in a groove of doing the same things day in and day out. And then, before you know it, the thirties arrive, along with a whole new wave of expectations.

My biggest fear is to live life with regrets. When I reach thirty, I want to be able to look back and see that I lived it to the fullest. To do this, I must continue to learn how to use my biggest fear to overcome my other fears. Please, let me have the strength and foresight to do so.

FCDH