I spent this week at the National Institutes of Health (NIH) in Bethesda, MD http://www.nih.gov/ . The NIH is funded by the U.S.government and has a campus full of scientists and doctors working on many different medical research projects. The scientists are all aiming to find out more about human diseases, such as heart disease and cancer, so that we can eventually use the knowledge they discover to help understand, diagnose or even cure diseases.

I visited a scientist (Karin) working in the National Institute for Neurological Disorders and Stroke (NINDS: one of 27 different institutes that make up the NIH). She works to improve a technique for taking pictures of the brain called Magnetic Resonance Imaging (MRI). MRI can also be used to take very detailed pictures (images) of many other parts of the body without using X-rays. Teams of scientists are working hard to try to improve the MRI images to give us more information about the brain and the human body.

MRI scanners use very strong magnetic fields produced by large superconducting magnets. Superconductors are materials which can carry a large electric current with very little electrical resistance. To stay superconducting, they have to be kept very cold and the magnets in MRI scanners are pumped full of liquid Helium (at a temperature of around minus 269 degrees Celsius or minus 453 Fahrenheit) to keep them cold enough. The magnets look like huge long doughnuts; the person to be scanned lies down inside the doughnut hole in the middle of the magnet.

When I arrived at the NINDS they were just installing a new MRI scanner. The magnet for the new scanner was going to have a magnetic field strength of 7 Tesla. Tesla is a measure of how strong the magnet is. Just to give you an example of what that means, it takes a magnet of around 1 Tesla to lift up a car made of steel in a junk yard! To make sure the new magnet would get cold enough to become superconducting and magnetic, it had to be pumped full of  liquid Helium. Before we could fill the magnet with Helium, we had to fill it with liquid Nitrogen first to start cooling it down. Here you can see a picture of me with big flasks (called dewars) of liquid Nitrogen, ready to be pumped into the new magnet behind them that will eventually be the new 7 Tesla MRI scanner:

The scientists develop new and improved ways of making MRI images. To develop and test those new imaging techniques they often scan healthy volunteers to see whether the new techniques produce high quality images of the volunteers; brains. Before volunteers can be scanned, they have to fill out a form to make sure they don't have any magnetic metal pieces in their body that could be pulled towards the magnet (see an example here). There is also a form to tell people about the MRI scan which explains a little more about how MRI works (click here to see that form).

Click on the link below to see an example of the kind of brain MRI images that I saw the scientists collect using the 7T scanner. It is really fascinating to be able to see what is inside our brains in such fine detail!

MRI_Brain_Images.pdf  

I also watched the scientists scanning volunteers in the older 7 Tesla MRI scanner that has been running for about 7 years. I couldn't go inside the room where the MRI scanner was because I have some metal parts in my body (that allow me to speak).  Below is a picture of me standing near the door of the 7 Tesla MRI scanner. You can see the signs warning people of the strong magnetic field. I'm also standing next to a big jar of bright orange ear plugs. Anyone who goes inside the MRI magnet for a scan has to wear ear plugs to protect their hearing because the MRI scanner can be very noisy when it is taking images.

Below are pictures of me taking some images using another type of scanner which only has space for very small samples and sometimes small animals like mice. It is a 14 Tesla magnet – twice as strong as the 7 Tesla human scanners, and you can see that this scanner sits upright so that this time the space for the samples runs vertically instead of horizontally. I could get closer to this magnet because it is much smaller than the human scanners and so its magnetic field doesn't reach out as far: