The effect of contrast agents on left ventricular parameters calculated by a threshold-based software module: does it truly matter?

The acquisition of short-axis (SA) cine magnetic resonance (MR) images after the administration of contrast agent (CA) is a common, time-saving technique, but a decreased difference in the blood-myocardium contrast on these steady-state free precession (SSFP) cine scans could change the calculated parameters when using threshold-based papillary and trabecular muscle (PTM) quantification. We studied the effect of CA on the parameters calculated from pre- and post-CA SA cine images in noncompaction cardiomyopathy (NC-CMP) and healthy (H) participants using a threshold-based module. A total of 39 individuals (20 patients and 19 healthy) were included prospectively in this study. After the pre-CA SA images were acquired, i.v. gadobutrol (GA) or gadobenate dimeglumine (GD) (GA vs. GD: NC-CMP = 12 vs. 8; C = 12 vs. 7) was administered, and SA scans were repeated after two minutes. A threshold-based PTM software was used for postprocessing. Pre-CA and post-CA SA images were analyzed, and the parameters were compared in both the NC-CMP and H groups. The left ventricular volumes were significantly larger, while the left ventricular myocardial (LVmass) and trabecular mass (LVtrab) values were significantly smaller on the post-CA scans (NC-CMP: pre-CA vs. post-CA, EDV: 74.0 ± 13.6 vs. 81.1 ± 16.3 ml/m(2), ESV: 25.3 ± 7.3 vs. 30.1 ± 11.2 ml/m(2), LVmass-ED: 82.5 ± 17.5 vs. 75.7 ± 15.9 g/m(2), LVtrab-ED: 25.0 ± 6.6 vs. 18.9 ± 4.7 g/m(2); Healthy: preCA vs. post-CA, EDV: 69.7 ± 11.9 vs. 72.2 ± 10.7 ml/m(2), ESV: 22.6 ± 5.7 vs. 23.9 ± 6.3 ml/m(2), LVmass-ED: 71.3 ± 13.6 vs. 68.7 ± 13.9 g/m(2), LVtrab-ED: 19.4 ± 2.6 vs. 16.2 ± 3.0 g/m(2); p < 0.05). The decreased blood-myocardium contrast difference on post-CA SSFP SA cine images leads to altered cardiac parameters when using threshold-based software for evaluation.