Effect of Gadoxetate Disodium on Arterial Phase Respiratory Waveforms Using a Quantitative Fast Fourier Transformation-Based Analysis

The purpose of this study is to investigate the effect of gadoxetate disodium administration on arterial phase respiratory waveforms. 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. 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). 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.