An in vitro study of contrast agent optimization for MR hysterosalpingography

BackgroundGadolinium-iodine mixed contrast agents can significantly improve the visualization of the fallopian tubes in magnetic resonance hysterosalpingography (MR-HSG). However, the mixing ratio of gadolinium-iodine contrast agents has not yet been standardized.PurposeTo explore the optimal mixing ratio of gadolinium-iodine contrast agents suitable for MR-HSG.Material and MethodsA total of 16 mixing ratios of gadolinium and saline mixtures (Gd-NS), gadolinium and iopromide mixtures (Gd-I370), and gadolinium and iodixanol mixtures (Gd-I320) were formulated for an in vitro study. These mixed contrast agents were scanned on 1.5 T and 3.0 T using T1 contrast enhancement sequences. For qualitative assessment, contrast agent imaging quality was graded on a subjective 3-point scale (good, moderate, and poor). For the quantitative evaluation, differences in the signal intensity (SI) of the three contrast agents, as well as the SI variations between 1.5 T and 3.0 T, were compared.ResultsGd-I370 and Gd-I320 exhibited the highest SI and good image at a 1:300 ratio on 1.5 T and a 1:200 ratio on 3.0 T. The difference in the SI among the three contrast agents was not statistically significant at 1.5 T (P > 0.05). At 3.0 T, the comparison between the SIs of Gd-I370 and Gd-I320 was not statistically significant (P > 0.05). The SIs of contrast agents on 3.0 T were higher than those on 1.5 T (P < 0.05).ConclusionA gadolinium-iodine contrast agent with a 1:300 mixing ratio may be more suitable for 1.5 T MR-HSG, while a 1:200 mixing ratio may be more suitable for 3.0 T MR-HSG. Additionally, the contrast agent SI is higher on 3.0 T than on 1.5 T.