Dynamic contrast-enhanced MR imaging of the prostate: intraindividual comparison of gadoterate meglumine and gadobutrol.

Abstract

To intraindividually compare the signal-enhancing effect of 0.5M gadoterate meglumine and 1.0M gadobutrol in dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging of the prostate. Fifty patients who underwent two 3-T MR examinations of the prostate were included in this IRB-approved retrospective uncontrolled, unrandomized study. All received two scans (mean time interval, 20.5months) including T1-weighted DCE-MR imaging, one with 0.5M gadoterate meglumine and one with 1.0M gadobutrol. Equimolar doses of gadolinium (0.1mmol/kg body weight) were administered with identical injection speed (2mL/s), resulting in differing gadolinium delivery rate. An identical region of interest (ROItz) within a BPH-node was identified on both scans. The area under the time-enhancement curve of each ROItz from 0 to 180s post contrast arrival and pharmacokinetic parameters were calculated. Relative enhancement and signal-to-noise (SNR) and contrast-to-noise (CNR) ratios in the delayed phase at about 180s were compared between both agents. There was a significantly larger area under the time-enhancement curve (5.53 vs 4.97 p = 0.0007) and higher relative enhancement of BPH nodules (2.23 vs 1.96 p < 0.0001) with gadobutrol compared with gadoterate meglumine. There were no significant differences in SNR (44.55 vs 37.63 p = 0.12), CNR (31.22 vs 26.39 p = 0.18), and pharmacokinetic parameters Ktrans (0.31 vs 0.32 p = 0.86), Ve (1.36 vs 0.98 p = 0.13), and Kep (0.34 vs 0.36 p = 0.12). At equimolar doses, increased gadolinium delivery over time using gadobutrol provides higher relative enhancement parameters in BPH nodules compared with gadoterate meglumine, but does not translate into improved SNR or CNR. • At equal injection rate and equimolar total dose, gadobutrol compared with gadoterate meglumine provides a significantly greater relative enhancement in DCE-MR imaging of BPH over the first 180s. • There are no significant differences in SNRs, CNRs, and pharmacokinetic parameters between the two GBCAs.