2007 Blood oxygen level-dependent MRI in myocardium and skeletal muscle at 1.5 T and 3.0 T
© Bernhardt et al; licensee BioMed Central Ltd. 2008
Published: 22 October 2008
Blood-oxygen level dependent (BOLD) cardiac magnetic resonance imaging (CMR) is a potential diagnostic tool to differentiate ischemic from non-ischemic myocardium.
T2* values of the myocardial and calf muscle were measured and compared between 1.5 T and 3 T to quantify the respective changes in the tissue T2* property, its dependency on the spatial resolution and to assess the sensitivity of the different field strength for hypoxia. T2* mapping of the calf muscle was performed in 15 volunteers before, during and after no-flow ischemia of the leg. In 23 healthy volunteers T2* maps of the myocardium were generated. Additionally, T2* was measured during adenosine infusion in eight volunteers.
Mean myocardial T2* at 1.5 T was 47.96 ± 10.69 ms and at 3 T 20.44 ± 4.49 ms. After obstruction of the leg the T2* reduction of the calf at 1.5 T was 3.4% (p = 0.001) and 13.0% at 3 T (p < 0.0001). T2* relaxation increased significantly during adenosine at 1.5 T and 3 T (p < 0.0001).
T2* quantification at 1.5 T and 3 T yields a linear relationship. No significant difference could be observed between breath hold and respiratory navigator gated techniques indicating the feasibility of T2* quantification at high spatial resolution. The T2* decrease during hypoxemia of the calf ant the increase during hyperemia of the myocardium indicate that our presented protocol could possibly be applied for evaluation of inducible myocardial ischemia.
This article is published under license to BioMed Central Ltd.