Cardiac magnetic resonance imaging:: long term reproducibility of the late enhancement signal in patients with chronic coronary artery disease

Objective: To determine long term reproducibility of the late enhancement (LE) signal in contrast enhanced magnetic resonance imaging (MRI) and potential changes of the signal after revascularisation. Methods: 33 patients (29 men, mean (SD) 61 (11) years) with coronary artery disease (CAD) and left ventricular dysfunction (ejection fraction 30 (7)%) underwent two contrast enhanced MRI procedures within 9 (3) months. Fifteen patients (group A: 14 men, 59 (12) years) had no interventions between the two studies. Eighteen patients underwent revascularisation after MRI 1 (group B: 15 men, 62 (9) years). Changes in the LE signal between the first and second MRIs were investigated in both groups as well as intraobserver and interobserver variabilities for delineation of the signal. Results: The LE signal was highly reproducible in groups A and B for segmental analysis (concordance 86% v 82%, respectively; k = 0.70 v 0.67) and summed scores (group A: r=0.97, p<0.001; group B: r=0.93, p<0.001). The LE signal was quantified as 27 (27) cm(3) in group A versus 30 (16) cm3 in group B in the first MRI and 26 (25) cm(3) versus 30 (15) cm(3), respectively, for the second MRI (both not significant). Moreover, low intraobserver and interobserver variabilities were observed in segmental analysis (k=0.86 and 0.74, respectively, for group A, and k=0.87 and 0.82, respectively, for group B). Conclusion: In patients with chronic CAD, the LE signal in contrast enhanced MRI is very stable over an extended time period. These results further characterise contrast enhanced MRI as a useful tool for myocardial viability assessment. Low intraobserver and interobserver variabilities promise robustness of the method for clinical application.