Fig. 6
User interface and output of the quantitative enhancement (QE) analysis software for comparison of GBCA enhancement. A manually delineated region of interest (ROI) that includes the entire enhancing region for both GBCAs is placed on the spatially registered T1-weighted unenhanced (a) and contrast-enhanced (b) images; the system then automatically calculates the per-ROI sum of QE values for each GBCA (QE map is shown in c). ROI scatter charts (d, e) of voxel enhancement on T1-weighted contrast-enhanced versus T1-weighted unenhanced images reveals the patterns of enhancement for each of the two GBCAs. A scatter chart of the voxel-by-voxel QE value of GBCA 1 versus GBCA 2 (f) reveals differences, if any, between the enhancement achieved with each GBCA. Summary statistics (g) provide information on the volume, number of voxels, and maximum extent of the lesion as well as details of the QE map voxel enhancement obtained, represented as “Sum/Weighted Volume” for each GBCA and as the “Sum Difference” between GBCA 1 and GBCA 2. In this case, the volume of interest was 16.157 cm3 and 3506 voxels were measured. The per-ROI sum of QE values (enhancement × cm3) was + 101.09 for the first examination with gadobutrol and + 109.87 for the second examination with gadoteridol. The 90% confidence interval of the mean of the differences (0.0025) was within the equivalence zone indicating that the enhancement achieved can be considered equivalent for the two GBCAs