February 2023

Transient severe motion artifacts on gadoxetic acid–enhanced MRI: risk factor analysis in 2230 patients.

Eun Bee Jang, Dong Wook Kim, Sang Hyun Choi, Seung Baek Hong, Taeyong Park, Yousun Ko, Su Jung Ham.

European Radiology (2022) 32:8629–8638. https://doi.org/10.1007/s00330-022-08885-2

Gadoxetic acid is a contrast agent used in MRI liver imaging. However, the appearance of the transient severe motion artifact (TSM) during the arterial phase may limit its use.

The authors analyzed retrospectively the risk factors involved in the appearance of this artifact and its relationship with gadoxetic acid in a large cohort. After applying the inclusion and exclusion criteria, 2230 patients who underwent a MRI at tertiary centre between January 2017 and June 2017 were selected. 

Inclusion criteria included: age over or equal to 18 years and have a MRI done between January 2017 and June 2017. Exclusion criteria included: absence of laboratory data or anthropometric measurements for at least one month prior to the test. 

The clinical information was obtained from the electronic database: demographic data, laboratory data, underlying disease, ascites and pleural effusion, and previous gadoxetic acid–enhanced MRI studies.

The degree of ascites and pleural effusion was analysed on the MRI examination.

Two board-certified radiologists evaluated TSM artifact on arterial phase images in gadoxetic acid-enhanced MRI using a 5-point grading scale. According to the severity of the artifact, patients were classified into two groups:

1.  non-TSM group, includes artifact grade of 0 to 3:  grade 1 or no artifact, grade 2 or minimal artifact and grade 3 or moderate artifact with some effect on diagnostic quality.

2.  TSM group, includes artifact grade of 4 or 5: grade 4, severe artifact that affects diagnostic quality but still interpretable. Finally grade 5 which consisted of extensive artifact with non-diagnostic images. 

The incidence of TSM using gadoxetic acid enhanced MRI was 5.0% (111/2230 examinations). Univariable and multivariable logistic regression analyses were performed obtaining the following results:

-The risk factors such as old age (≥ 65 years) [OR = 2,01 (1,31–3,07)], High Body Mass Index (BMI ≥ 25 kg/m2) [OR = 1,76 (1,18–2,63)], chronic obstructive pulmonary disease (COPD) [OR = 6,11 (2,32–16,04)], and moderate to severe pleural effusion [OR = 3,55 (1,65–7,65)], were recognized as significant independent risk factors for TSM occurrence.

-Hepatitis B and previous gadoxetic acid–enhanced MRI studies was associated with a lower risk of TSM occurrence, [OR = 0,66 (0,43–0,99)] and [OR = 0,52 (0,33–0,83)], respectively. In this study, hepatitis B was an independent negative risk factor probably because these patients have previous MRI studies and some of them do not have advanced cirrhosis.

Based on risk factors (age > 65 years, BMI > 25 kg/m2, COPD, moderate to severe pleural effusion, no hepatitis B, and no previous experience of gadoxetic acid), the predictive risk of TSM was 0,6% in the absence of risk factors,5,7% if at least one of the significant factors was present, and this percentage increased to 16,3% with at least four risk factors.

In addition to the current study, many of these patients underwent examinations with an extracellular contrast agent within 1 year (138/2230).  This fact allowed the authors of the study to create a subgroup analysis to compare the incidence of TSM with hepatospecific and extracellular contrast agent. The incidence of the TSM was higher with gadoxetic acid-enhanced MRI (McNemar test:  9,5% vs 2,2%, p =0,006).

The authors acknowledge the following limitations: selection bias due to retrospective study design, studies obtained from Korean institutions where the hepatitis B virus is endemic and low incidence (5%) compared with previous meta-analysis (13%).