Next Generation MR Diagnostic Tool May Transform Cardiovascular Patient Outcomes

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The role of perfusion imaging in clinical decision-making is in the process of being refined. Magnetic resonance (MR) perfusion imaging allows measuring blood flow to the heart muscle with an unprecedented spatial resolution and without any ionizing radiation. Multicenter data have already suggested the superiority of this technique in comparison to methods now used on a routine basis.

New findings presented by Prof. Dr. Eike Nagel, chair of clinical cardiovascular imaging at King’s College London (UK), presented during the 12th annual scientific sessions (January 29 to February 1, 2009) of the Society for Cardiovascular Magnetic Resonance (SCMR), held in Orlando, FL, USA, demonstrate an expansion of MR perfusion’s role, suggesting that new techniques with faster imaging will further improve spatial resolution and enhance diagnostic accuracy.

MR perfusion imaging may also be used in patients after bypass surgery. This is due to its ability to discriminate areas with scar from complex flow patterns as found after surgery. Similarly, the high spatial resolution allows detecting remaining areas of reduced blood flow after therapy. These new areas for using MR perfusion imaging, according Prof. Nagel, expand the indications of this comparatively young technique and lead to a reconsideration of the application of MRI mostly as a second line technique.

Data from a German registry on the utilization of cardiovascular MR in clinical practice covering nearly 10,000 patients demonstrates that this technique will generate a final diagnosis in more than 70% of the patients. In the registry, 16% of the patients came up with a different diagnosis after the scan, than what was to be expected before the test.

These numbers are even more convincing when the complexity of the patients is taken into account. Most of the patients already underwent several other diagnostic tests before the cardiovascular MR examination. These numbers further underline the benefit of cardiovascular MR in clinical cardiology practice. In addition, the use of cardiovascular magnetic resonance as a first line technique, rather than late during the diagnostic workup of patients needs to be considered.

The registry will now be extended to an international level with participation of more than 50 major diagnostic centers. “Given the amount of information we get from a single examination, ranging from the size and function of the heart, through scar tissue after myocardial infarction, to an excellent visualization of myocardial blood flow,” said Christoph Klein, M.D., from the German Heart Institute Berlin. “We should use magnetic resonance imaging as the premier imaging technique in a large group of patients.”

Additional research is geared towards quantitative assessment of myocardial blood flow to allow clinicians not only to discriminate between normal and abnormal blood flow, but also to measure the effect of therapy and to individually guide patient management, according to the researchers.