MRI imaging

Today John and I took the scorpions to St. Joseph’s hospital for the MR (magnetic resonance) imaging.

After considering various ways to kill the scorpion we had selected to image (subject cannot move during imaging), I decided to have the scorpion anesthetized so that it would be easier to handle, then made an incision across its back, right behind the eyes to sever the spinal nerve. We then proceeded to place the dead scorpion in a 50mL vial filled with water and insert it into the MR machine.

Because of the tendency of the scorpion tail to bend, we had some difficulties getting a clear image. We decided that, as we were primarily concerned with getting images of the structure of the tail, to remove it an image it alone (because the tail is not very wide we could put it in a much smaller vial, thus keeping it straight). This improved our images but lead us to discover that we were not getting a strong enough signal from the internal structures of the tail. This was due to the fact that an MR machine sees hydrogen atom nuclei (protons), and as our subject was suspended in water, we were getting a large signal from the water surrounding the tail, thus masking the weaker signal originating from the tail itself (akin to taking a picture of something with the sun behind it). To fix this we switched the water for a perfluorinated fluid (a hydrocarbon-like molecule where all hydrogen atoms have been replaced with fluorine) atoms that does not have a magnetic signal.

After all of this we were finally able to get a clear image. The high resolution scanning was started with an estimated time until completion of six and a half hours.

Advertisements

One thought on “MRI imaging

  1. Pingback: Second scorpion MR | Barrett's Projects

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s