Quantitative assessment of myocardial perfusion with a spin-labeling technique: preliminary results in patients with coronary artery disease.

Purpose: To determine perfusion and coronary reserve in human myocardium without contrast agent using a spin labeling technique.

Materials And Methods: Assessment of myocardial perfusion is based on T1 measurements after global and slice-selective spin preparation. This magnetic resonance imaging (MRI) technique was applied to 12 healthy volunteers and 16 patients with suspected coronary artery disease under resting conditions and adenosine-induced vasodilatation.

Results: In volunteers, quantitative perfusion was calculated as 2.4 +/- 1.2 mL/g/minute (rest) and 3.9 +/- 1.3 mL/g/minute (adenosine), respectively. Perfusion reserve was 2.1 +/- 0.6. In patients, when comparing perfusion reserve in the anterior and posterior myocardium, reduced values according to a stenotic supplying vessel could be seen in seven of 11 patients who underwent stress testing. In these patients, the relative difference of coronary reserve was 44% +/- 18%. Two patients without stenosis of coronary arteries showed no differences in coronary reserve (with a relative change of 2 +/- 2%).

Conclusion: In patients with single-vessel coronary artery disease, differences in coronary reserve were clearly detectable when comparing anterior and posterior myocardium. The spin labeling method is noninvasive and easily repeatable, and it could therefore become an important tool to study changes in myocardial perfusion.