Please activate JavaScript!
Please install Adobe Flash Player, click here for download

EH 1_2015

Improved security for the patient! The injector itself remains wireless and mobile! Improved workflow in angiography! Keep track of things! Hauptstrasse 255 · D-66128 Saarbruecken For more info: Contrast medium injectors and consumables for CT, MRI and angiography For Philips & Siemens angiography devices! NEW: DVI-interface between Accutron® HP-D and monitors EUORPEAN_HOSPITAL_1-4_Seite_HPD.qxp_Anzeige 18.02.15 09:21 Seite 1 EUROPEAN HOSPITAL  Vol 24 Issue 1/15 10 EH @ ECR also the scatter and reflectance of the external excitation light, degrad- ing the sought after signal. With Cerenkov luminescence imaging the light emanates from the radiotracer within the body. It is an ultra low signal that requires total darkness and very sensitive cameras to be detected. ‘We calculate this light is one billion times weaker than ambient light in an operating room, Grimm explained. ‘To image Cerenkov light means shielding it from this billion- times stronger light, otherwise it would be like trying to see a candle held up against the sun. ‘We have shown that we can do this even in the clinical setting. This provides us with two types of infor- mation coming from one source – the radioactive agent. We, and other groups, are now working to create specific agents that make use of the Cerenkov light and some very unique features that allow us to do some very neat tricks’. One advantage is better quantifi- cation of the light, he said. ‘There are all sorts of light propa- gation models for radiotracers, but with Cerenkov light we can abso- lutely measure the radioactivity and then calculate how much light is being generated. We can determine the difference between the light actually generated and the light arriving at the detector, which allows us to calculate an absorption factor for light. Or, as we demonstrated, we can use the light and modulate it to create radiotracer-based sensors, switching Cerenkov on or off with smart tracers to provide additional information one cannot get with just radioactivity alone.’ Another advantage of Cerenkov luminescence imaging is the cost of the camera, which is 25% of the cost of a PET scanner. Additionally, in pre-clinical animal studies, where usually one mouse can be imaged at a time with PET, Grimm pointed out, ‘we can image five mice at the same time and it takes about five minutes.’ The ability to capture Cerenkov luminescence remains the great challenge. Going inside the patient during endoscopic procedures shows promise because the human body serves as a natural shield for the faint blue light. Xenon aids exposure of previously unseen structures Xe-MRI advances body exploration Medical physicist Leif Schröder has led the Molecular Imaging research group at Leibniz Institute for Molecular Pharmacology (FMP) in Berlin since 2009. Their focus is on the development of Xenon biosensors that highly increase the significance of magnetic resonance imaging (MRI). Schröder gained an initial five-year grant from the European Research Council to explore the potential of these novel contrast agents. Among the physicist’s many awards are the Emmy-Noether research fellowship and the Philips Research Prize for medical physics. ©SilkeOsswald,Leibniz-Institutfür MolekularePharmakologie,Berlin Clinical routine would be inconceivable without Magnetic Resonance Imaging. Without exposure to radiation, doctors can make a patient’s organs and tissue structures clearly visible. However, pathological changes in the early stages, degenerated cells or small areas of inflammation, have so far remained almost invisible on these images. In 2014, for the first time, a team of cell biologists, chemists and physicists working with Dr Leif Schröder, Head of the ERC-Project on Biosensor Imaging at the Leibniz-Institute for Molecular Pharmacology (FMP) in Berlin-Buch, succeeded in generating ‘two-colour’ images for different molecular markers with the help of Xenon-MRI. Report: Sascha Keutel Xenon-MRI (Xe MRI) was developed in the mid-1990s to facilitate diag- nostic imaging of the lung. Unlike conventional MRI it does not detect water molecules but instead the non-poisonous, noble gas Xenon. The system then directly visualises the ventilated lung areas. For new kinds of imaging, first a contrast medium is administered, which binds specifically to the marker and accumulates in the diseased tissue. Then Xenon is administered, either via inhalation of a mixture of gases containing Xenon, or dissolved in substances such as blood plasma. Advantage: These directly injectable substances can be available in the blood stream immediately. The FMP scientists aim to bind Xenon gas combined with biosen- sors, like a contrast medium, to go precisely to disease-specific mark- ers in the tissue. ‘We very recently published the results of a first study where we could bind Xenon biosen- sors to certain glucose structures on the cell surface. These play a certain role in tumours and can- not be visualised with other MRI contrast media. This was proof that the technology has made structures visible for the first time that were previously inaccessible via MRI,’ Schröder reports. The scientists also succeeded in marking different cell types so that they send out radio waves on differ- ent frequencies. In the same way as with a light microscope they gener- ate images where some cells glow in red, others green. The researchers used a concept from the world of laser physics where the Xenon sig- nal is amplified about 10,000 times – the gas is ‘hyperpolarised’. In the test object itself they then rescind this situation in a controlled man- ner through a co-action between the biosensor and the MRI exposure sequence. This results in a further amplifica- tion, with an order of magnitude of around three, and allows the detec- tion of relatively small amounts of the specific marker. In the first step, biosensors without Xenon are administered that selectively bind to diseased cells or, respectively, are washed out in other locations. Once the Xenon has dissolved in the nutrient solution for the cells – or later in the patient’s blood- stream – the bound sensors become visible and show the sites of patho- logical changes. Then the Xenon is detected; in the MRI it ‘gives itself away’ through a certain resonance frequency in the MRI when bound in the sensors. The images are then superimposed with conventional MRI images to obtain anatomical as well as biochemical information (such as in the PET/MRI hybrid procedure). Xe MRI has various fields of application With the help of Xe MRI the researchers aim to significantly expand the range of applications for MRI. They are convinced that, Faster than lightCerenkov luminescence merges optical imaging with nuclear medicine in a novel modality Report: John Brosky PET scanners are not the only way to image radiotracers. Recent work developed around a phenomenon called Cerenkov luminescence aims to bring a new modality out of pre- clinical development and into clini- cal practice. First noted by Marie Curie, it was Soviet physicists who first described the strange blue light that occurred when charged particles travelled through water. Among the Russian group was Pavel Alekseyevich Cerenkov, who shared a Nobel Prize in 1958 for this work. Long applied in nuclear physics, the Cerenkov effect is now being developed for use in nuclear medi- cine and biomedical imaging. At the ECR, on Saturday, Jan Grimm MD PhD presents the lec- ture ‘Cerenkov: Faster Than The Speed Of Light’, offering a review of this new method that promises new ways to image radiotracers and describing advances in both tech- nological developments and clinical studies. ‘Optical imaging with radiotrac- ers is one of the very few new and novel modalities described in recent years,’ said Grimm, who is an Assistant Professor at Memorial Sloan Kettering Cancer Center and Cornell University, New York. He is a Laboratory Head and also Assistant Attending Radiologist in the Radiology and Nuclear Medicine group at Memorial hospital. ‘By combining optical light and radioactivity, we are merging the two fields of optical imaging and nuclear medicine, which creates a whole range of new opportunities with possibly huge advantages for patient care. This is totally new, and can be brought relatively quickly into the clinic because the tracers are all available. We just have to figure out the right clinical setting.’ In conventional optical imaging a light is projected onto the area of study to excite an injected fluoro- chrome. The more external light, the stronger the obtained signal – but The technique is being used in animal studies Metastastic SLN PNG - enhanced - with scale and colourbar1 EUORPEAN_HOSPITAL_1-4_Seite_HPD.qxp_Anzeige 18.02.1509:21 Seite 1

Pages Overview