Some Main Stream Media (MSM) news about CT

The MSNBC homepage (msn.com) today had a link about CT scans may raise cancer risk. To a Medical Physicist, this is pretty old news. Unfortunately, for the general public, this may actually be something new. Nothing in the name of CT imply the use of X-ray, even though a chest CT is easily equivalent to hundreds of chest X-rays. Most people I know seem to understand that a Chest X-ray is somewhat harmful, and should not be repeated again and again without good reason. But if you ask people the harm of CT, they would be pretty surprised to know that a CT is as bad as hundreds of chest X-rays. I think it's a good thing that the general public learn more about the harm of CT.

Just for your information, a chest CT has a dose of 8 mSv. A chest X-ray has a dose of 0.02 mSv. The background radiation received by the general public is about 4 mSv per year, and the upper limit of occupational exposure for non-nuclear energy worker is 1 mSv.

Here's the link.

Nuclear medicine making a come back?

During my undergrad, when people talk about Medical Physics, they assume it's either external beam radiotherapy, or CT/MRI imaging. Sometimes Health Physics is included. Rarely was nuclear medicine mentioned. But apparently, with the introduction of PET/CT combined scanner, nuclear medicine as its own specialty is making a come back. The use of radioactive source and x-ray imaging requires a special type of Physicist, the Nuclear Medicine Physicist. Until now, the role and responsibility of Nuclear Medicine Physicist is not yet well defined, but we should see changes in this area soon. In external beam therapy, for example, various protocols have been established by either AAPM or ICRU to define the required treatment quality as it pertains to physics. We may expect to see similar things being introduced to Nuclear Medicine, specifically to PET/CT scanner.

On LSO scintilation crystal

Like almost any technology, medical devices go in and out of vogue all the time. One thing I find worth noticing is the growth in Nuclear Medicine due to the introduction of PET/CT imaging. Just like IMRT spurred explosive growth in external beam radiotherapy, PET/CT scan promises to do the same to nuclear medicine imaging. One of the technologies in development is LSO scintillation crystal, used in PET detectors. Compared to older BGO crystals, it has certain merits. The raw source, Lutetium, cost about six times as much as gold. Considering that scintillation crystals are macroscopic sized, the cost of raw element would be considerable.

Lutetium is a rare earth element, commonly found with other Lutetium. As I learned in grade school, China is a major exporter of rare earth elements. (Can you tell I'm Chinese? It's one of the few things I learned in the Communist brainwashing.) Chances are, most Lutetium in the world is produced in China. Another example of the interdependence of global economy. China can't produce LSO based detectors, but it produces the raw material, and uses the devices produced.

The pesky problem called snow

It's Montreal after all, so I shouldn't be surprised to see snow in November. It doesn't make me feel any better walking around in boots, though. Being the only one from West Coast in my class, it doesn't feel very good to adjust to the cold weather. Oh well, at least I live kinda close to the hospital. Let's see how I fare in the coming months.

Bizzare experience with contact lens

Having paid for PGSS insurance, I decided to get something out of it. The natural first step would be contact lenses, as I don't have contacts yet. The buying was pretty smooth, even though I had to front the cash and get reimbursed. After I got home, the contacts turned out alright. I've only had hard contact lenses before, and never got used to them enough to wear them daily. The soft contact lenses are much easier on my eye, although they're quite difficult to put on for someone inexperienced like me.

Having put two on, I suddenly found that my right eye was blurry. Thinking that I lost it, I sighed for the cost, and opened another lens and put it on. Two hours later, the contacts were that comfortable, so I took them off before having dinner. Putting my glasses back on, I went on with my things. A while later, I suddenly found that my right eye couldn't see well. Somehow, there's a contact in my eye! I took that off, look at all three of them, now lying in lens boxes. The only conclusion I could make, was that I had two contact lenses in my right eye.

A brief Google search didn't return anything. That's it for now. Hope the contacts work out well for me.