Abstract: Objective Gadoxetic acid disodium (Gd‑EOB‑DTPA) enhanced magnetic resonance imaging (MRI) plays a crucial role in the detection and characterization of hepatic lesions, However, arterial phase images are frequently degraded by transient severe motion (TSM) artifacts, which may be associated with body mass index (BMI). This study aims to investigate the relationship and dose⁃response association between BMI and TSM in Gd⁃EOB⁃DTPA enhanced MRI, and to provide the evidence for the accurate identification and prevention of arterial⁃phase TSM. Methods This prospective study enrolled patients with liver lesions who underwent Gd⁃EOB⁃DTPA enhanced MRI at Guangxi Medical University Cancer Hospital from March 2024 to November 2025. Multivariable Logistic regression was used to evaluate the association between BMI and arterial⁃phase TSM. Four stepwise adjusted models were established. Model 1 was unadjusted, Model 2 adjusted for demographic factors, Model 3 additionally included lifestyle factors, and Model 4 was comprehensively adjusted for clinical covariates. Subgroup analysis was performed to observe the correlation between BMI and arterial TSM across different populations. Restricted cubic splines (RCS) were applied to explore potential non⁃linear relationships. Results A total of 792 patients were included in the study and categorized into three groups: the underweight/normal⁃weight group (n=484), the overweight group (n=158), and the obese group (n=150). Arterial⁃phase TSM occurred in 270 patients (34.1%). After adjustment for relevant confounders, compared with the underweight/normal⁃weight group, the obese group had a significantly higher risk of arterial⁃phase TSM (OR=2.88, 95%CI: 1.82-4.55; P<0.001). A 1⁃standard⁃deviation increase in BMI (4.51 kg/m²) was associated with a 49% higher risk of arterial⁃phase TSM (OR=1.49, 95%CI: 1.26-1.77; P<0.001). RCS analysis showed a linear positive association between BMI and arterial⁃phase TSM within a BMI range of 15-40 kg/m² (P for overall association<0.001; P for nonlinearity=0.927). Subgroup analyses indicated a significant interaction between prior Gd⁃EOB⁃DTPA enhanced MRI history and the BMI⁃TSM association (P for interaction=0.016). Conclusions Obesity is an independent risk factor for arterial⁃phase TSM on Gd⁃EOB⁃DTPA enhanced MRI, and the risk of arterial⁃phase TSM increasing with BMI. Clinical practice should pay particular attention to patients with elevated BMI, especially those undergoing first⁃time examinations, by implementing implement targeted preparation and acquisition strategies to improve arterial⁃phase image quality.

Key words: Liver cancer, Gadoxetic acid disodium, Enhanced MRI, Respiratory motion artifact, Body mass index, Obesity