written by Matthew L. Hayes BSRS RT (R)(MR)(CT)
Adjunct Faculty | Radiologic Sciences| Online Learning
Adventist University of Health Sciences
This blog is contributed thanks to our very own Professor Matthew L. Hayes, an adjunct professor of CT and MRI at Adventist University of Health Sciences. Professor Hayes has spoken at events for the Radiological Society of North America (RSNA) and the American Society for Radiation Oncology (ASTRO) and brings more than 13 years experience in the field to ADU. He graduated from ADU with his associates and bachelors in radiologic sciences and has been fortunate to travel the world and learn from some of the brightest minds in the field. In this blog series, he will be contributing updates to his imaging work at ADU and abroad.
As I walk down the jet way to board my flight to State College from Philadelphia, I see what has to be the smallest plane in the fleet. It’s my plane. It’s a prop plane that looks like it’s meant to
hold 10 people, tops. I say a quick “here we go” under my breath and cling to hope. I have to admit, it was a terrific flight. As we were descending, I saw what had to have been “happy valley”- nestled between mountain ranges on either side. After I de-board, I’m met by one of my close friends, Dr. Brian Johnson, from the Penn State University Center for Sport Concussion Research and Service (http://concussion.psu.edu/). Before focusing on research and academia, he was a full time MRI Tech. The reason I make this trip from the Sunshine state to the Keystone state is to take part in the “travelling phantom” imaging project for the Concussion Neuroimaging Consortium (CNC: http://www.concussionimaging.org/index.html). CNC is comprised of various universities and leaders in imaged based concussion research. In the coming weeks, I will travel to the CNC institutions to optimize and standardize imaging sequences and protocols across different vendors and locations.
Being a pretty insane college football fan (Roll Tide), I can see why even visiting teams’ fans love to visit Penn State. Passing beaver stadium, you can see and feel how important football is. 9 out of 10 people wear only blue and white and are very proud of their school. The weather is mild, the town is charming and the campus is beautiful. I like it here. I attended ADU for my associates and my bachelors degree and loved my school. It was big to me, but this is on another level. Having never attended a public school, I’m always awestruck by the shear enormity of it all.
After a walk along college and beaver streets, Brian and I stop by his lab and he shows me some projects that they’re working on. We nerd out for a while. Anyone who knows me knows how excited I get about MRI. I honestly feel like there’s no ceiling to the uses of MRI. It’s potential seems endless. Put me in a room with these guys and I can talk shop for hours. Its closing time for those in the lab so Brian spends a good part of the evening showing me all the good places to eat. There’s no shortage of food in state college. There’s an Austrian restaurant that the owner yells at you if you don’t eat all of your food. As tempting as that sounds, I opt for a burger from Primanti Brothers. It’s one of the best I’ve ever eaten. I can feel myself getting chubbier. I’ll worry about all that later. When in rome, I say. When in Rome.
Brian has us set up in the apartment of a colleague of his. I unpack and grade some papers and answer some e-mails. We then (as is tradition) sit down and talk all things MRI. We also try and convince the other that we’re the best tech out of the two of us. In the end I let him think it’s a tie.
The next morning, Brian has some proprietary work to do in the lab, so I grab some breakfast before we’re booked to begin. We later meet at the chandlee building, right behind “old main”. This is where all the MRI research takes place and houses a 7T and a 14T magnet. The magnets are so powerful, they have very small bore openings which only allow imaging to be performed on small animals such as mice and fish. The pictures they yield are amazingly high in detail and spatial resolution. Did I mention that I like it here? For human research, they utilize a 3T Siemens Prisma. To date, it is the most advanced 3T production scanner ever built- boasting a 64 channel coil configuration as well as an industry best, 80mT/m gradient configuration. Having such a supercharged gradient system means that the rise time of the gradients can up to full strength for imaging in less time. As a result, you can have shorter scan times and capture data faster-especially in EPI sequences.
One of the more interesting EPI sequences to me these days is the blood oxygen level deficiency (BOLD) technique. We are utilizing it within our concussion protocol to measure the brain’s activity during rest following a concussion. It is the technique of choice for functional MRI (fMRI) and is based on the brain’s need for new oxygen after activity. Anything you think about, anything you see, any move you make requires your brain’s neurons to fire off electrical signals to either give a command or process data. In order to fire, they need oxygen rich blood called oxyhemoglobin. After the neuron has fired, the blood is filled with deoxyhemoglobin, which is paramagnetic and will have susceptibility artefact secondary to phase shift. Assuming the brain continues to perform activities, cerebral blood volume will increase to supply it with new blood. BOLD imaging is measuring the difference in phase shift from oxyhemoglobin to deoxyhemoglobin. Only areas in the brain that are being used will require it. As a result, we can understand what areas of the brain are being used when you tap a finger or even where certain emotions originate from. BOLD fMRI imaging has been a valuable tool in unlocking many behavioral mysteries as well as understanding what tasks certain parts of the brain control.
As with any EPI based sequence that fills k-space with one TR period, peripheral nerve stimulation (PNS) may occur. PNS is basically involuntary muscle movement caused by time varied magnetic fields. I could actually feel in the lower right side of my back twitching in rhythm while being scanned. It wasn’t uncomfortable by any means. I always like things like this so I can be more empathetic and informative to my patients that I scan.
After the rest of our phantom scans had been performed, we download the scanning data to an external hard drive to be processed later. We thank Brenda, the staff technologist on site, and are off. Its been a long and productive day in happy valley. I fly out early tomorrow morning. I love going new places, but I strongly dislike the actual travel. I can only imagine the size of my plane out of there. I’m less than excited to go through security. All that can work up an appetite. I’m thinking Austrian food would hit the spot.