Combined coronary lumen and vessel wall magnetic resonance imaging with i-T2prep: influence of nitroglycerin.

Abstract

It has been shown that sublingual nitroglycerin (NTG) improves image quality of coronary lumen magnetic resonance angiography. Our aim was to investigate the influence of NTG on coronary lumen and vessel wall image quality using a combined, single sequence approach (i-T2prep), which is able to image both within the known time frame of action of NTG. Ten healthy volunteers underwent right coronary artery lumen and vessel wall imaging using the i-T2prep sequence before and after administration of NTG. Image quality was assessed qualitatively and quantitatively. Diameter, length and wall thickness were also measured using dedicated semi-automatic software. NTG induced coronary vasodilatation (lumen diameter increased from 2.16±0.32 to 2.52±0.59mm; p=0.036). As a result, visualized lumen length (9.8±2.6 to 11.4±3.3cm; p=0.025) and qualitative lumen image quality (median 3 (interquartile range 2-3.25) vs. median 3 (interquartile range 3-4); p=0.046) both improved. Vessel wall imaging also demonstrated a significant improvement in vessel wall sharpness after NTG (24.8 vs. 27.3%; p=0.036). This study demonstrates the benefits of NTG for coronary lumen and vessel wall imaging using a combined sequence, i-T2prep. The methodology described here has great potential for future pathophysiological studies.