"By cooperating with the hospital we can make better use of research data, which makes me work more efficiently"

Martijn Nagtegaal (Delft University of Technology - Applied Physics), PhD student with the scientific programme Medical Delta Diagnostics 3.0: Dementia and stroke, is researching MR Fingerprinting. This is a technique that allows you to get faster and more accurate scans, and measures the underlying values in the brain. Ultimately, he hopes that these advanced scans will help us better understand how dementia develops.

This interview is the third in a series of interviews with PhD candidates and PostDoc researchers. Martijn’s research is funded by the scientific programme: Medical Delta Diagnostics 3.0: Dementia and stroke.

What motivates you to do your research?

I studied technical mathematics and physics, and I have always been fascinated by MRI research. With the MRI scanner, you can, unlike the CT scanner, turn a lot of knobs and set the MRI scanner in many ways to create different images. I like the puzzle of these settings, and constantly trying to see more.

What has your research revealed so far?

At the moment, we use qualitative scans in black-grey-white for MRI scans. This means that you only see the brain in grey tones. A deviation can only be seen due to the difference in colour between one spot and the other, but not by the exact value. I am researching quantitative MRI, which does not show the grey values but measures the underlying absolute values of the tissue properties. Because we can compare these numbers between multiple people over time, the given results will be more widely usable. With which we can develop a method to detect dementia, for example.

The brain consists of white and grey matter. In people with dementia, you often see that the white matter in the brain decreases. With which you can tell early on that they have the disease. But with current scans it is difficult to see exactly where the white matter ends and the grey matter begins. With MR Fingerprinting, the technique I'm researching, you can create many more images than with the scanner we're currently using, sometimes as many as 500 in a row. So you can see very precisely how much white or grey matter is present somewhere.

I am very happy that we can work closely together with doctors within Medical Delta.

What I have now achieved with my research into MR Fingerprinting is that we can make faster MRI scans that are also more accurate. That can give more insight into changes in the brain in one person. And you can compare the scans with those of other people, giving a more accurate picture of any abnormalities. In this way, I hope that we will get a better picture of dementia. With these new insights, I hope that we will be able to detect dementia in people at an earlier stage and that we will be able to make a more accurate diagnosis.

How does the collaboration in Medical Delta benefit your research?

I am very happy that we can work closely together with doctors within Medical Delta. My supervisor suggested that I needed a clinician as co-supervisor, and that turned out to be a very good idea because it raises other questions and ensures that I keep an eye on practice. For one of the papers I wrote, I needed MRI scans from ten people. I wanted to approach research participants, but the corona pandemic made it difficult to get scans. Dr Dirk Poot, a researcher at Erasmus MC and one of my co-promoters, heard about the problem and told me that he still had scans from a similar study. I could use the data that he and Laura Nunez-Gonzalez (PhD student at Erasmus MC) had collected earlier. So, by cooperating with Erasumus MC, we make better use of research data and share the knowledge, which makes me work more efficiently. I also work closely with the MRI specialists of the LUMC. These kinds of collaborations take my research further.

What do you want to do when you finish your PhD?

I still have a few months to go and I really enjoy what I do: both the research and supervising students. That is why I would like to continue in science. One of the things I would like to work on is making research protocols and scans from different MRI scanners interchangeable. At the moment there are scanners in Leiden and Rotterdam and other cities in the Netherlands made by different manufacturers. I would like to develop a protocol that makes it easier to share the developed MRI sequences, without someone having to reprogram it based on a publication. That would make exchanging advanced MRI scans much easier.

Bo Li, whose interview appeared last month, asked: what advice would you give to the next generation of researchers?

Look for cooperation! I have several supervisors who each have their own input and vision, and I learned a lot from them. And I worked together with two master's students, both physicists. Without their contribution, I would not have been able to develop my research so far.