Nieuwe MRI-methode voor de bloedstroom in de hersenen

 Op dit moment worden elk jaar  ongeveer honderd van deze gespecialiseerde MRI-scans uitgevoerd bij het  UMC Utrecht. De methode wordt officieel aangeduid als arteriele spin-etikettering, of ASL. De bloedstroom in de hersenen kan worden gevisualiseerd door magnetisch etikettering van watermoleculen met radiofrequente pulsen. Deze methode spoort  alle gebieden van de hersenen op die te weinig of te veel bloed krijgen.Engelstalig bericht

Doctors at UMC Utrecht are using the method mainly in two types of patient. Firstly, patients who have had surgery for a brain tumor are sometimes left with residual tumor tissue. The ASL method of an MRI scan can differentiate between harmless scar tissue and residual pieces of tumor where blood flow is higher. Secondly, in patients who undergo brain bypass surgery for a brain infarction or stroke, the ASL MRI method can be used to see which areas of the brain have a poor blood flow. This is very useful for estimating the best place for placing the bypass.

“I think that we will probably use the method for about ten to twenty percent of all our MRI brain scans”, says radiologist Dr Jeroen Hendrikse of UMC Utrecht. He is supervising the research into the ASL method of magnetic resonance imaging. “In recent years, the images have become clearer and clearer and we can now make them in less time. We have also noticed that both radiologists and doctors who request MRI scans are becoming more aware of the possibilities of this method “.

Advantages
The ASL method has several advantages. The actual procedure takes only four minutes and can be performed in one go with a regular MRI scanner. Moreover, no contrast agents are necessary. Although contrast agents are not harmful in principle, they cannot be used in patients who have a poor kidney function, for example. Moreover, a contrast fluid has to be administered through an infusion into a blood vessel but no infusion is necessary with the ASL method. Incidentally, blood vessels and blood flow can also be visualized through CT scans and other types of scanners but these expose patients to small amounts of radiation.

Although the ASL method is new, it has been around for twenty years. During the last ten years, doctors and researchers at UMC Utrecht have been among the first in Europe to use this method with patients. In their experience the ASL method improves diagnoses.

Radiologist in training Reinoud Bokkers will receive his doctorate on this subject on July 8, 2011 from the University Medical Center Utrecht.