Above all, radiologist Jeroen Hendrikse is a busy man. Despite the many research grants that he has received for his MRI study on local causes of stroke – including a VIDI grant in 2011 and an ERC starting grant in 2014 – he continues to perform his normal clinical work. ‘As a researcher, if you’re not careful, things will become increasingly complicated. It’s good to be confronted with day-to-day reality, in which we still don’t understand many common clinical pictures.’ Hendrikse sees questions as challenges: ‘I’m still not able to answer all of the questions from the other specialists in the treatment team. For example about the effect of the selected treatment.’ Judging from his drive, this is only a matter of time.
Pipes, Perfusion and Parachyma
If you were to make a drawing of of a specialist, it would probably look a lot like Jeroen Hendrikse: striped shirt, short, bristly hair and small metal-framed eyeglasses. He shifts restlessly in his chair. “We already know a great deal about strokes caused by small blood clots (embolism) from the heart or the jugular vein that become lodged in the smaller arteries of the brain. However, we still don’t know very much about strokes that originate in the small arteries of the brain. Until recently, it was impossible to chart these types of strokes. The powerful 7 Tesla MRI scanner now makes it possible to scan the small blood vessels in the brain.’ His post-doctoral research started with perfusion, the quality of the circulation in various parts of the brain. He also brought the small blood vessels of the brain into view; the quality of these vessels is one of the determinants of the reserve capacity of blood vessels in the skull after damage has occurred. He succeeded in visualising the entire vascular wall. ‘This technique is now being applied for young patients as well, in which inflammation in the vascular wall is often the cause of stroke.’ Finally, he charts and characterises the damage, which he summarises as ‘Pipes, Perfusion and Parachyma.’
‘I think one of the nicest things about radiology is the collaboration with all types of specialists, including neurologists, neurosurgeons, epidemiologists, physicists, pathologists and vascular surgeons. The UMC Utrecht has a tradition of working in multi-disciplinary teams. We are a world leader in this regard. For example, I am working with Prof. Luijten’s 7 Tesla team, which includes all of the users of this powerful MRI scanner. Radiologists are obviously expected to bring defects into view. Before they can do that, however, they need to have a clear idea of what they are looking for. That’s the challenge. Which contrast are we looking for; what do we want to see?’
‘In global perspective, the clogging of the small arteries of the brain (atherosclerosis) is the most important cause of strokes, although it appears to be the cause of only a small share of the strokes in Europe. We need to know if this is actually the case. More than half of all strokes are due to unknown causes. I am going to be following 100 patients who are at increased risk for stroke in order to determine how strokes occur and what types of damage they cause. I am also using data from a larger-scale epidemiological study in which MRI scans were made in successive years and in which a great deal of patient data were collected. In addition, I will be conducting post mortem brain studies, which often reveal minor strokes.’
The goal is stated ambitiously in his ERC proposal: ‘I aim to understand the cause of stroke in every single patient.’ Although the proposal developed by Hendrikse was initially rejected, the questions raised by the evaluating committee spurred him on to refine his ideas. ‘I was ultimately able to explain the importance better. I also answered every possible question. For example, I would not be able to conduct this study using the brains of laboratory animals, because they are too small.’
So many questions, so little time. ‘As a leading researcher, your work has to be your hobby. For example, part of my vacation was spent on a working visit to Hong Kong. The pay-offs are huge; once we know more about the origin of strokes, we can start to design specific treatments.’ And then? ‘Oh, there is plenty to do. MRI is only one method; nuclear techniques are also quite promising.’ You can almost see the next project on the horizon.
Written by: Youetta Visser