| Purpose To investigate the effects of multiple arterial phase(AP)scanning,singleAP scanning with different breath-holding time,and patients' characteristics on the image quality of arterial phase.Materials and Methods The imaging and clinical data of 603 consecutive patients(409 males,194 females,mean age 54±11y)who underwent Gd-EOB-DTPA-enhanced MRI from October 2017 to September 2018 in our hospital were retrospectively analyzed.All patients were randomly assigned to three MRI machines for examination:group 1,205 cases(quadruple AP with 16s scanning time);group 2,199 cases(single AP with 17s scanning time);group 3,199 cases(single AP with 13s scanning time).Thirty-four patients underwent both multiple AP and single AP scanning,and 11 patientsunderwent all three scanning protocols.The image quality was evaluated,including motion artifacts in plain,AP and portal venous phase,phase timing of AP,enhancement satisfaction of solid organs.Patients' basic characteristics were also collected,including sex,age,maximum abdominal diameter,degree of ascites,pleural effusion,history of lung disease,liver cirrhosis,fatty liver,history of partial hepatectomy,history of local treatment of intrahepatic lesions,and diameter of the largest lesion in the liver.The scoring system of motor artifacts was as follows:1,no motion artifact;2,minimum motion artifact,no effect on diagnosis quality;3,moderate motion artifact;4,severe motion artifact,image degradation,but still can be judged;5,wide range of motion artifacts,images can not be diagnosed.And score 1 and 2 were defined as high image quality.The scoring system for phase timing of AP was as follows:1,no contrast medium in hepatic artery;2 contrast medium was seen in hepatic artery in the early stage of artery,but there was no contrast medium in portal vein and hepatic parenchyma;3,the peak period of arteries,that is,arterial enhancement,portal vein and hepatic parenchyma enhancement,but no hepatic parenchyma enhancement and hepatic vein enhancement;4,too late,that is,hepatic parenchyma enhancement or hepatic vein enhancement.And score 2 and 3 were defined as satisfactory AP phase timing.The scoring criteria for satisfaction enhancement of solid organs was whether liver parenchyma is mild enhancement,spleen is macular enhancement,pancreas enhancement is good;renal cortex contrast is good,and satisfaction is score 2,not satisfied is score 1.Non-parametric test was used to compare the differences of motion artifacts in each group.One-way ANOVA was used to compare the differences of age,abdominal transverse diameter and maximum diameter of the lesion among groups.Chi-square test was used to compare the differences of gender,ascites,pleural effusion,history of pulmonary disease,presence or absence of cirrhosis,fatty liver,partial hepatectomy,local treatment history,and the phase distribution of AP among groups.The Pearson and Spearman correlation test was used to analyze the relationship between age,gender,ascites,pleural effusion,history of pulmonary disease,cirrhosis,fatty liver,history of hepatectomy,history of local treatment and motion artifacts in AP.Paired-sample t-test was used to compare the motion artifacts in AP in patients with both multiple and single AP scanning.Differences repeated measures ANOVA were used to compare the motion artifacts in AP in patients with three scanning protocols.Results(1)Plain and portal venous phase:there were statistical differences in motion artifact scores between the three groups(P<0.05).There was no difference between group 1 and 3(P<0.001).Group 2 was significantly lower than group 1 and 3(P<0.05).(2)AP:there was no significant difference in the mean motion artifact scores between the three groups(P=0.074),and the best score of group 1 was significantly higher than that of group 2 and 3(P<0.01).There was no significant difference in motion artifacts between group 2 and 3(P=0.698).(3)Arterial phase timing:the phase distribution of arterial phase obtained in the best scoring phase of group 1 was not statistically different from that in group 2 and group 3(P=0.202).(4)When both high-quality image quality and satisfactory phase timing of AP were considered,the proportions obtained by group 1,2 and 3 were 76.0%,62.82%,and 75.38%,respectively.The proportions obtained by group 1 and 3 were significantly higher than group 2(P<0.05),and there was no significant difference between group 1 and 3(P=0.866).(5)The maximum transverse diameter of the abdomen was slightly correlated with motion artifacts in AP(r=0.124,0.131,0.132;P=0.038,0.033,0.032,).The age was slightly correlated with motion artifacts in AP(r=0.124,0.131,0.132;P=0.047,0.005,0.014).The history of hepatectomy was correlated with motion artifacts of AP in group 1 and group 3(r=0.151,0.132;P=0.031,0.032).(6)The motion artifact score of AP in different scanning protocols was similar in patients underwent both multiple AP and single AP scanning,or all three scanning protocols(P>0.05).ConclusionIn Gd-EOB-DTPA-enhanced liver MRI,the mean artifact score of multiple AP scanning was similar to single AP,but the artifact score of best image in multiple AP was better than that in single AP scanning.There was no improvement in image quality by shortening four seconds breath-holding time in single AP scanning.When the best image quality was selected in multiple AP scanning,the phase timing of AP was similar to single AP scanning.The maximum transverse diameter of abdomen and the age were influencing factors of the image quality in AP. |
PDF Full Text Request