LAUSR

PURPOSE To clarify the relationship between transient sever motion artifact in arterial phase (TSMA) and changes in peripheral capillary oxygen saturation (SpO2) and heart rate (HR) after contrast media administration during MRI or CT of the liver. METHODS 87 patients undergoing 61 MRI examination with gadoxetic acid or 26 CT examination with iodinated contrast were included. Dynamic contrast-enhanced imaging (DCEI) was obtained at four vascular phase acquisitions. Reviewers extracted the segmental data of SpO2 and HR in each phase from consecutive data in DCE-CT or DCE-MRI. In addition, reviewers scored for respiratory motion in each phase using 5-point scale. Patients with an arterial score of 4-5, and other phase scores of 1-2 were considered to be exhibiting TSMA. RESULTS In gadoxetic acid, mean SpO2 of arterial phase was significantly lower than three other phases (P = 0.045 to P < 0.001). However, the decrease in SpO2 in arterial phase compared with other phases was <1%. Mean HR in gadoxetic acid or iodinated contrast agent was highest in the portal-phase. The incidence of TSM was 0% in patients with iodinated contrast agent and was 8.2% (5/61 patients; TSM group) in patients with gadoxetic acid, respectively. In addition, there was no significant difference in mean SpO2 of arterial phase between the TSM group (97.5% ± 1.08%) and non-TSM group (96.4% ± 1.85%) (P = 0.219). CONCLUSION The slight decrease in SpO2 in arterial phase is not associated with TSMA.