Transient Severe Motion Artifact on Arterial Phase in Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging

The aims of this study were to determine the incidence of transient severe motion artifact (TSM) on arterial phase gadoxetic acid-enhanced magnetic resonance imaging of the liver and to investigate the causes of heterogeneity in the published literature.Original studies reporting the incidence of TSM were identified in searches of PubMed, Embase, and Cochrane Library databases. The pooled incidence of TSM was calculated using random-effects meta-analysis of single proportions. Subgroup analyses were conducted to explore causes of heterogeneity.A total of 24 studies were finally included (single arterial phase, 19 studies with 3065 subjects; multiple arterial phases, 8 studies with 2274 subjects). Studies using single arterial phase imaging reported individual TSM rates varying from 4.8% to 26.7% and a pooled incidence of TSM of 13.0% (95% confidence interval, 10.3%-16.2%), which showed substantial study heterogeneity. The pooled incidence of TSM in the studies using multiple arterial phase imaging was 3.2% (95% confidence interval, 1.9%-5.2%), which was significantly less than in those studies using single arterial phase imaging (P < 0.001). In the subgroup analysis, the geographical region of studies and the definition of TSM were found to be causes of heterogeneity. The incidence of TSM was higher in studies with Western populations from Europe or North America than in those with Eastern (Asia/Pacific) populations (16.0% vs 8.8%, P = 0.005). Regarding the definition of TSM, the incidence of TSM was higher when a 4-point scale was used for its categorization than when a 5-point scale was used (20.0% vs 11.0%, P = 0.008), and a definition considering motion artifact on phases other than arterial phase imaging lowered the incidence of TSM compared with it being defined only on arterial phase imaging (11.3% vs 20.3%, P = 0.018).The incidence of TSM on arterial phase images varied across studies and was associated with the geographical region of studies and the definition of TSM. Careful interpretation of results reporting TSM might therefore be needed.