For your short relaxation times.
In the course of developing ReviseMRI.com, I’ve read lots about how to make an interesting, interactive web site which is user (and browser) friendly. The biggest noise made about this concerns web standards.
If you’re designing websites, the following may provide some interesting reading. (If not…maybe skip this post.) Continue Reading »
In a past interview for research funding (a Fellowship award), I boldly stated
“Statistics makes the research-world go round.”
Whilst my eagerness to impress the interviewers is now embarrassingly obvious to me, I don’t think the statement is all that far from the truth. Here’s one case in point: it is well established that confidence intervals (CIs) communicate more useful information than P values in hypothesis testing. Continue Reading »
Artificial heart valves are usually safe for MRI, because any torque or attraction forces exerted by the external magnetic field are minimal compared to the force exerted by the beating heart. However, there is an interesting safety issue surrounding the induction of electric current in the artificial heart valve, which might theoretically compromise the function of some heart valves, in rare cases. The issue is the Lenz effect (aka eddy current damping).
The unit of magnetic field is the Tesla, named after Nikola Tesla (visionary / genius / crazy / misunderstood et cetera). A company named after Tesla is Tesla Motors, who make the Tesla Roadster. Check this out:
Magnetic media (e.g. your credit card) may be affected at field strengths of 3 millitesla (mT). For comparison, this magnetic field strength is about 100 to 200 times stronger than the normal magnetic field on the surface of the Earth (depending where you are on the planet). The 3 mT field line around a typical shielded 1.5 T MRI magnet is about 2 metres from the side of the magnet, and less than 3 metres from the ends of the magnet.
Notice that the magnetic field around an MRI magnet is 500 times smaller than the strength at the isocentre at just 2 to 3 metres distance!
I wonder how the magnetic field affects the newer chip-and-pin microchip which is embedded in credit cards. Anyone care to comment?