EH 4_2015

www.healthcare-in-europe.com L O N D O N • G R E AT B R I TA I N 2 9 A U G - 0 2 S E P 2 0 1 5 www.healthcare-in-europe.com A new kid on the block, PET/MR enables the acquisition of soft tis- sues definition and contrast unseen in PET/CT. The new hybrid com- bines both PET and MR strengths – excellent spatial resolution with molecular data – an alliance that has begun to tickle the interest of the cardiology community. ‘What are we going to get when we put PET and MR together?’ asks Bristol-based cardiologist Dr Chiara Bucciarelli-Ducci, who has used MR extensively in her work. ‘Potentially a lot,’ she added, ‘but we still don’t know because it’s early days.’ Cardiac imaging, she believes, is still very much a niche for PET/MR, but its potential in myocardial func- tion makes it an attractive option. ‘Although these machines were not developed for cardiac imaging, but rather oncology, their potential in myocardial infarction assessment represents an opportunity. Acute myocardial infarction is the nearer development and this is where car- diac MRI has really been worked on, to find some constraints that hope- fully now, adding PET, we’ll be able to understand better.’ MR pictures of recent myocardial damage usually show a large scar with micro vas- cular structure on top. Adding PET to the formula, cardiologists can not only see a lack of metabolism in the damaged area itself, but also in sur- rounding segments. ‘What it means is still a bit unclear, but it offers unprecedented pathophysiological opportunities to understand these complex process- es,’ Bucciarelli-Ducci said. For the last few years, MR has been an exciting tool for interven- tional radiologists in myocardial salvage after primary percutane- ous coronary intervention (PPCI) in acute ST-segment elevation myo- cardial infarction, to show the area at risk as end point for successful PPCI. Simply put, MR is increasingly used because it allows a reduction of miscalculation. Stress MRI is excellent to image induced myocardial ischemia; combining it with PET could also increase diagnostic accuracy. PET/MR also holds promise in sarcoidosis and acute myocarditis, an acute inflammatory disease of the heart. ‘The potential here is really immense. The question is really how do we combine the During a session focused on innova- tions in cardiovascular imaging, at the British Cardiovascular Society annual conference (Manchester in June), Professor Dudley Pennell, Director of the Cardiovascular Magnetic Resonance (CMR) Unit, and Director of Non-Invasive Cardiology at Royal Brompton and Harefield NHS Foundation Trust, outlined the background to dif- fusion tensor imaging (DTI). He explained how the technology yields information on water diffu- sion in tissue and is widely used by neurologists. It allows the mapping of the diffusion process of water molecules in biological tissues, in vivo and non-invasively, with the water molecule diffusion patterns revealing microscopic details about tissue architecture, either normal or in a diseased state. Tractography Through seven individual measure- ments taken by MRI, the DTI can map out the path of neurons and myocytes using an image processing technique called tractography. ‘With brain tractography, the images are colour-coded for direc- tion and it reveals amazing details in 3-D and is used by neurologists to map where the neurons are going,’ Pennell explained. ‘It also has an application for the heart and can image the organisation of myocar- dial cells.’ DTI has been around since the mid-1990s but until recently has been a slowly evolving tech­ nology. It has taken huge steps for- ward with the use of acceler- ated imaging, advanced tech- nology, and high field magnets (3-Tesla). Within cardiology, it has an application for cardio- myopathy, myocardial infarction and congeni- tal heart disease. The challenges ‘There are, however, major challenges for cardiac DTI,’ the professor added. ‘Because of the move- ment, there is a need for advanced motion freezing techniques, for spatial and temporal reso- lution and the complexity of myocardial architecture also pose challenges.’ DTI is an evolving discipline and one that is revealing stunning images that will help in the diagnos- tic process, particularly with hyper- trophic cardiomyopathy (HCM) and there may yet be a range of further cardiac applications that it may have a role in, Pennell suggested. He showed how abnormal contraction in hypertrophic cardiomyopathy has been shown to result from abnor- mally reduced rotation of blocks of myocytes, called sheetlets, which are organised contractile structures in the heart consisting of many myocytes. ‘With Cardiac DTI the current approaches appear promising and it is improving our understanding of normal cardiac structure,’ he con- cluded. During the same session, Derek Hausenloy, Professor of CardiovascularMedicineatUniversity College London and Duke-National University of Singapore, outlined the role of Hybrid PET/MR imaging in cardiac disease. A technology that has only been available since 2011, he said it had the advantage in that the PET ele- ment images the biological process and MR the tissue characteristics. Hausenloy: ‘Through that, we are gaining new pathophysiological insights into cardiac disease.’ information and how do we want to use these techniques,’ she added. PET/MR has long been studied for oncology but the technique also holds promise in cardiovascular applications, according to a panel of experts at the recent International Conference on Nuclear Cardiology and Cardiac CT (ICNCT), Mélisande Rouger reports. An innovative imaging technique, more commonly used in neurosurgery, is finding fresh applications within cardiovascular imaging. Diffusion tensor MRI is an evolving form of imaging that is offering new insights into tissue architecture, Mark Nicholls reports. PET/MR is promising Improved soft tissue definition and contrast Diffusion tensor MRI A consultant cardiologist and lecturer at the UK’s Bristol Heart Institute, Dr Chiara Bucciarelli-Ducci also co-directs the Clinical Research and Imaging Centre (CRICBristol) and leads creative medical research (CMR ) at the Bristol National Institute of Health Research (NIHR) Biomedical Research Unit (BRU). Dudley Pennell is Professor of Cardiology at the National Heart and Lung Institute, Director of the National Institutes of Health Research Cardiovascular Biomedical Research Unit located at Royal Brompton Hospital, and additionally he directs the Cardiovascular Magnetic Resonance (CMR) Unit. New imaging technique offers insights in cardiovascular tissue. Continued on page 10 N E W S A N D T E C H N O L O G Y U P D A T E S F O R C A R D I A C C A R E CARDIOLOGY 2015 L O N D O N • G R E AT B R I TA I N 29 A U G - 02 S E P 2015

Pages Overview