Magnetic Resonance Myocardial Perfusion Imaging (MRMPI)- A New Era in the Detection of Reversible Myocardial Ischaemia

Stuart Watkins ^1*, Keith G Oldroyd ² and Stephen Frohwein ³

¹ Western Infirmary, Glasgow, United Kingdom
² Western Infirmary, Glasgow
³ American Cardiovascular Research Institute

^* To whom correspondence should be addressed. E-mail: s.watkins{at}clinmed.gla.ac.uk.

Accepted 1 August 2006

Abstract

The currently employed tests for the detection of reversible myocardial ischaemia have a number of limitations. Exercise electrocardiography has only moderate sensitivity and specificity (68% and 77%).1 Single photon emission computerised tomography (SPECT) has improved sensitivity of 86% and equivalent specificity of 74% but the radiation exposure is considerable at between 8 and 20 millisieverts depending on the radioisotope utilised and the images are frequently degraded by photon scatter and attenuation artefacts.2. Positron emission tomography (PET) is widely regarded as the non-invasive gold standard but it is expensive, requires radioisotopes and has very limited availability in the UK. Stress echocardiography involves no radiation and can be utilised in conjunction with either exercise or pharmacological stress. It has comparable sensitivity and specificity to SPECT but a proportion of patients have inadequate imaging windows.3 Multidetector CT coronary angiography (CTA) is a relatively new imaging modality which was reviewed in the journal last year.4 As with nuclear imaging techniques radiation exposure is not insignificant and like conventional coronary angiography it is not possible to confirm the functional significance of any stenoses identified.5 6