Semi-quantitative myocardial perfusion measured by computed tomography in patients with refractory angina: a head-to-head comparison with quantitative rubidium-82 positron emission tomography as reference.

INTRODUCTION

Computed tomography (CT) is a novel method for assessment of myocardial perfusion and has not yet been compared to rubidium-82 positron emission tomography (PET). We aimed to compare CT measured semi-quantitative myocardial perfusion with absolute quantified myocardial perfusion using PET and to detect stenotic territories in patients with severe coronary artery disease.

MATERIALS AND METHODS

Eighteen patients with stenosis narrowing coronary arteries ≥70% demonstrated on invasive coronary angiography underwent rest and adenosine stress imaging obtained by 320-multidetector CT scanner and CT/PET 64-slice scanner. CT measured myocardial attenuation density (AD) and perfusion index (PI) were correlated to absolute PET myocardial perfusion values.

RESULTS

Rest AD, rest and stress PI did not correlate to PET findings (r = 0·412, P = 0·113; r = 0·300, P = 0·259; and r = 0·508, P = 0·064, respectively). However, there was a significant correlation between stress AD and stress PET values (r = 0·670, P = 0·009) and between stress and rest differences for AD and PI with PET differences (r = 0·620, P = 0·006; and r = 0·639, P = 0·004, respectively). Furthermore, significant differences were observed between remote and stenotic territories for rest and stress AD (48 ± 14HU and 37 ± 16HU, P = 0·002; 76 ± 19HU and 58 ± 13HU, P<0·001, respectively), PI (9·6 ± 2·9 and 7·5 ± 3·1, P = 0·002; 21·6 ± 4·1 and 16·9 ± 3·9, P<0·001, respectively) and PET (0·96 ± 0·37 ml g  min and 0·86 ± 0·26 ml g  min , P = 0·036; 2·07 ± 0·76 ml g  min and 1·61 ± 0·76 ml g  min , P = 0·006, respectively).

CONCLUSIONS

Semi-quantitative CT parameters may be useful in the detection of myocardium subtended by stenotic coronary arteries.