Monday, October 09, 2006

A Science Article I Won't Mock

As the article points out, the inability to give MR scans to patients with pacemakers is a non-trivial problem--MR provides a lot of information that is not easily obtained otherwise.

This is cool.

The article does describe a few different approaches. One is covering the patient with a blanket that shields the pacemaker from rf interference. Presumably, given both the technology and the company, this is similar in nature to the building of a stealth airplane. Again, making some assumptions, it's likely that the device will not be suitable for scanning near the pacemaker--if you block out the rf, you can't get an image in that area.

The Medtronics approach relies on making a better pacemaker. This is probably the best long term solution--although we have to keep in mind that with MR scanners reaching higher and higher fields, and with gradient technology improving, there will always be limits to what you can do. But this could be a breakthrough.

The third method is not well described. It repeatedly uses words like "dose" that don't make a lot of sense in an MR context. My best interpretation is that, roughly speaking, the researchers looked at which pacemakers could be scanned by using low flip-angle scans.

Flip angle is a parameter in MR that's not talked about much in popular news, on the basis that it's not easily explained. Roughly speaking, one aspect of this is that you can reduce the flip angle to reduce the heat deposited in the body (this is actually a big deal, but that's another post). Naturally, this comes at a cost, the most obvious of which is that the images have lower signal--that is, they look grainer.

That said, if in even a few cases it's possible to image someone with a pacemaker without special equipment, that's cool. Risky, but with a huge payoff...


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