Objective: The purpose of this article is to identify risk factors for arterial phase respiratory motion artifact in gadoxetate disodium-enhanced liver MRI.
Materials and methods: We retrospectively identified 220 consecutive patients who underwent 357 MRI examinations, including 68 patients who underwent multiple MRI examinations, with gadoxetate disodium between 2010 and 2013. The arterial phase timing was determined by a fluoroscopic-triggering method. T1-weighted unenhanced and contrast-enhanced images were reviewed to record respiratory motion artifact, which was graded on a 5-point scale. Arterial phase transient severe motion was considered to be present if the motion score was 4 or greater on the arterial phase images and if the motion scores were 2 or less on unenhanced and other contrast-enhanced images. Patient characteristics and risk factors (e.g., age, sex, weight, body mass index, medical and radiologic history, allergy to MRI and iodinated contrast agents, estimated glomerular filtration rate, Child-Pugh class, and findings on current MRI examinations) were recorded. We included a history of transient severe motion on prior MRI as a predictor variable. We performed univariable and multivariable analysis using the generalized estimated equations to adjust for clustering.
Results: The incidence of transient severe motion was 12.9% (46/357). On univariable analysis, a history of transient severe motion (odds ratio [OR] = 3.31; p = 0.04) on prior MRI and allergy to iodinated contrast agent (OR = 3.03; p = 0.01) statistically significantly increased the incidence of transient severe motion for a given MRI examination. These associations were not seen on multivariable analysis (adjusted OR = 2.38 and p = 0.23 for a history of transient severe motion; adjusted OR = 1.93 and p = 0.23 for allergy to CT contrast agent).
Conclusion: The occurrence of transient severe motion during arterial phase MRI with gadoxetate disodium is 12.9% and is poorly predicted on the basis of risk factors.
Keywords: MRI; artifact; gadoxetate disodium.