Myocardial function and perfusion assessment with exercise stress cardiovascular magnetic resonance using an MRI-compatible treadmill in patients referred for stress SPECT
© Thavendiranathan et al; licensee BioMed Central Ltd. 2012
Published: 1 February 2012
Exercise stress cardiac magnetic resonance (CMR) has recently become feasible with the development of a fully MRI-compatible treadmill system along with improvements in imaging techniques. The utility of this setup has not been systematically compared with nuclear perfusion imaging. The study objective was to evaluate the accuracy and prognostic value of exercise stress CMR with a treadmill placed immediately next to the MRI scanner table in patients referred for treadmill stress nuclear perfusion imaging.
Exercise time averaged 10.0±2.9 minutes. Exercise ECG was interpretable during all stages of exercise in 95% of the patients. Stress cine imaging commenced on average at 28±5sec following end of exercise, and stress function and perfusion were completed by 64±7sec, vs. previously reported 42±5sec and 88±8sec, respectively, using a partially modified treadmill in the corner of the scanner room. Agreement between SPECT and CMR for the detection of ischemia and scar was moderate (κ = 0.56). Accuracy for detection of significant CAD in the 21 patients who had coronary angiography was 21/21 for CMR and 17/21 for SPECT (p = 0.13). Follow up at 8-12 months indicated excellent prognosis, with all patients with negative CMR or SPECT having no coronary events.
Exercise stress CMR using an MRI-compatible treadmill to assess wall motion and perfusion was feasible, accurate, and had good prognostic value in patients with suspected ischemic heart disease. Larger-scale, multicenter studies are needed to confirm our initial experience that suggests comparable accuracy of exercise CMR vs. SPECT to identify myocardial ischemia and infarct scar due to CAD.
National Institute of Health (NIH).
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