Objective: The purpose of this study is to investigate the effect of gadoxetate disodium administration on arterial phase respiratory waveforms.
Subjects and methods: From 2013 to 2015, 107 subjects undergoing liver MRI with either gadoxetate disodium (10 mL diluted 1:1 with saline; injection rate, 2 mL/s; n = 40) or gadobenate dimeglumine (0.2 mL/kg; maximum, 20 mL; injection rate, 2 mL/s; n = 67) were enrolled. Respiratory waveforms obtained during unenhanced and dynamic contrast-enhanced phases were filtered by a physicist, who was blinded to contrast agent and imaging phase, to eliminate electronic and cardiac noise using fast Fourier transformation. The average root-mean-square difference of two intrasubject control phases (unenhanced and late dynamic) was termed D1, and the root-mean-square deviation of the arterial phase referent to the control record mean was termed D2. D1, D2, and their difference were compared across agents with the Mann-Whitney U test. Bland-Altman plots were generated for D1 and D2 values.
Results: D1 values were similar for both agents (mean [± SD], 232 ± 203 for gadoxetate vs 201 ± 230 for gadobenate; p = 0.48), indicating similar intercohort baseline breath-holding capability. D2 was greater and more variable for the gadoxetate cohort (438 ± 381) than for the gadobenate cohort (167 ± 167; p < 0.001), indicating larger and more unpredictable respiratory waveform deviations isolated to the arterial phase (subject-level rate, 48% [19/40] for gadoxetate vs 1% [1/67] for gadobenate; p < 0.001). Aberrant respiratory waveform peaks in the arterial phase were usually associated with transient tachypnea (mean maximum arterial phase respiratory rate for the gadoxetate cohort, 27 breaths/min; range, 11-40 breaths/min).
Conclusion: Fixed-dose gadoxetate disodium (10 mL; 1:1 dilution with 10 mL of saline; injection rate, 2 mL/s) transiently reduces breath-holding capacity during the arterial phase and is accompanied by brief transient tachypnea.
Keywords: arterial phase; gadoxetate disodium; respiratory; transient dyspnea; transient severe motion.