Being interested in science often means digging a little deeper.

Being interested in science often means digging a little deeper.

Originally shared by Chad Haney

Safety first

A lot of people seem to be sharing the story about the guy who died in Mubai from an MRI accident. I figured I should clear up a few things because all of the stories I’ve seen so far have a lot of mistakes.

There’s no way liquid oxygen is involved. He died from his chest getting significant trauma from the oxygen cylinder. I’ve never heard of someone dying from breathing in too much pure oxygen (except divers, premature babies, etc.) I’ll grant that it is possible if he was stuck there for a long time. However, I’m assuming that the patient had a small portable E cylinder, not the H size cylinders that you might see welders use.

The magnet didn’t quench so he was not breathing helium (from the boiling liquid helium). You can certainly die of asphyxiation when a super-conducting magnet quenches but that’s not what happened. This article said that the cylinder was still there the next day. https://goo.gl/aHCaZz

Patient oxygen cylinders are almost always steel, and heavy iron steel at that, not stainless steel. If a patient needs oxygen, they often have tubes going into the MRI room so that the gas cylinder can be a safe distance away, most likely in a “tank closet”. A tank closet has many cylinders with a monitoring system that automatically switches from an empty cylinder to a full one. Many hospitals actually have huge liquid oxygen storage tanks outside and pump gaseous oxygen throughout the building into patient rooms, operating rooms, etc. Whoops, let’s get back on track.

MRI magnets ARE ALWAYS ON. We have a sign on the door for maintenance, janitorial, and emergency personnel. When you turn the MRI “off”, i.e., ramp down the magnetic field, it’s a slow, deliberate process. One of our MRI scanners has a liquid helium regenerating system. We ramp down the field every two years to replace that system. It has to be done very carefully and slowly. You also tend to lose liquid helium in the process. So turning an MRI “off” would be expensive.

This story reminds me of the website that collects MRI accident images.

http://www.simplyphysics.com/flying_objects.html

I hope Lacerant Plainer has a better article to point me to but here’s what I have so far.

Mumbai MRI accident: Ward boy told us machine was switched off, said relative of deceased

Hindustan Times

https://goo.gl/urJVjn

Image source:

https://radiologykey.com/wp-content/uploads/2016/01/c17-fig-0003.jpg

For background on MRI and CT see my #CHMedicalImagingSeries

Medical Imaging 101 pt 3: MRI

http://goo.gl/UVbiU

What is MRI quenching, you ask? Read more here:

https://plus.google.com/u/0/+ChadHaney/posts/HrrgtcK7NHU