Application Of Magnetic Resonance Six-echo Dixon Rapid Liver Fat Quantification In Patients With Obese Type 2 Diabetes Mellitus

Part1 Magnetic resonance six-echo Dixon rapid quantification of liver fat content in obese type 2 diabetes mellitus patientsObjective:1.Using High-speed T2-corrected multi-echo(HISTO)magnetic resonance spectroscopy as a reference standard,evaluation of the accuracy of 1.5T magnetic resonance six-echo Dixon in the quantitative assessment of liver fat content(LFC)in patients with type 2 diabetes mellitus(T2DM).2.Using the traditional manual delineation of the region of interest(ROI)to measure the whole liver fat content as a reference standard,evaluation of the accuracy and feasible of the six-echo Dixon rapid quantitative method in quantitative assessment of the average liver fat content of patients.Materials and methods:37 patients(20 males and 17 females)with T2DM diagnosed by endocrinology were prospectively selected,and body mass index(BMI)was?25 kg/m2.All subjects underwent 1.5T magnetic resonance with a scan of liver axial T2W1 and FS-T2Wlto observe whether there is a substantial disease in the liver.The patient's LFC was pre-evaluated by using dual echo Dixon to form a LFC screening report,and then the LFC was accurately quantified by using six-echo Dixon sequence and HISTO sequence.After the six-echo Dixon sequence scan,the computer can automatically segment the liver.The whole liver average LFC is generated as a rainbow report.The result is recorded as LFC-Rapid,HISTO sequence's Volume of interest(VOI)placement in the ??? segment of the liver,the measurement results are also automatically calculated by the computer,and the result is recorded as LFC-HISTO.The fat fraction(FF)map generated by the six-echo Dixon sequence is transmitted to the Siemens post-processing workstation for processing as follows:1.Manually draw three ROIs in different areas of the right ??? segment of the right lobe,and the ROI measurement area should be consistent with the VOL measurement range in the HISTO sequence as much as possible.,and the final result is recorded as LFC-R;2.In the eight segments of the liver,the ROI was manually drawn from the available slice,and the LFC of each liver segment was recorded.Finally,the LFC of the whole liver was obtained by averaging method and recorded as LFC-Manual.The Bland-Altman plots and Spearman correlation analysis were performed on the results of LFC-HISTO and LFC-R?LFC-Rapid and LFC-Manual,respectively.Result:1.In our study,78%(29/37)of obese T2DM patients had liver fat deposits(LFC>5.6%);2.Spearman correlation analysis showed:the result of LTC-HISTO measured by HISTO sequence is highly correlated with the LFC-R measured by six-echo Dixon sequence(r=0.987,P<0.01).The Bland-Altman analysis showed that the average difference between the LFC-HISTO and the LFC-R was 0.22(95%confidence interval,-0.97 to 1.40)and 35/37 differences were within range of 95%confidence interval;3.The magnetic resonance six-echo Dixon rapid liver fat quantification results LFC-Rapid were highly correlated with the traditional manual draw ROI measurements result LFC-Manual(r=0.963,P<0.01).The Bland-Altman analysis showed that the average difference between the LFC-Rapid and the LFC-Manual was 0.80(95%confidence interval,-0.63 to 2.23)and 36/37 differences were within range of 95%confidence interval;Conclusion:The six-echo Dixon technique liver fat quantification results are similar to the HISTO measurements.Compared with traditional manual drawing ROI measures the average LFC,the six-echo Dixon rapid liver fat quantification method can simply,feasibility and accurately assess the average LFC.Part 2 Magnetic resonance Dixon rapid liver fat quantification in the dynamic monitoring of obesity type 2 diabetes patientsObjective:Using Six-echo Dixon rapid liver fat quantification dynamic monitoring the change of LFC,body weight,waist circumference,BMI,waist-to-hip ratio(WHR),fasting blood-glucose(FPG),glycosylated hemoglobin(HbA1c),total triglyceride(TG),high Density Lipoproteins(HDL-C),Low Density Lipoprotein(LDL-C),Systolic Blood Pressure(SBP),and Diastolic Blood Pressure(DBP)in the obesity patients with T2DM.To investigate the correlation between LFC and body weight,waist circumference,BMI,WHR,FPG,HbA1c,TG,HDL-C,LDL-C,SBP and DBP at baseline.Furthermore,the correlation between LFC changes after 3 months of treatment and changes in body weight,waist circumference,BMI,WHR,FPG,HbAlc,TG,HDL-C,LDL-C,SBP and DBP was also analyzed.Materials and methods:Prospectively selected obese patients with T2DM and they lost the weight and controlled the blood glucose according to the Chinese Type 2 Diabetes Prevention Guide(2013 edition)recommended intensive lifestyle intervention with acarbose of a three-month treatment period.The patient's LFC was assessed before and after treatment using 1.5T magnetic resonance six-echo Dixon rapid fat quantification.The LFC during the baseline period was recorded as LFC-Before,and after 3 months of treatment was recorded as LFC-After,and the change of LFC after 3 months of treatment was recorded as ?LFC.The patient's body weight,waist circumference,BMI,WHR,FPQ HbAlc,TG,HDL-C,LDL-C,SBP and DBP were also recorded while acquiring magnetic resonance image.Finally,there were a total of 28 patients(16 males and 12 females)with complete data and clear image,and the average age of(50.14±10.50)(the range was 35-64 years).Results:There was a significant correlation between LFC-Before and waist circumference(r=0.602,P<0.001)and body weight(r=0.527,P=0.004)and BMI(r=0.493,P=0.008)and WHR(r=0.618,P<0.001)and HbA1c(r=0.475,P=0.026)and LDL-C(r=0.382,P=0.045)in obese T2DM patients at baseline.However,LFC-Before and FGP(r=0.326,P=0.091)and TG(r=0.244,P=0.211)and HDL-C(r=-0.162;P=0.41)and SBP(r=0.004,P=0.984)and DDP(r=0.098,P=0.618)has no significant correlation at baseline.After 3 months of treatment,LFC,body weight,BMI,waist circumference,WHR,HbAlc,FPQ TG,HDL-C were significantly improved compared with the baseline period(P<0.05),and LDL-C,SBP,DDP(P=0.939,0.260,0.125)no significant change from the baseline period.The significant correlations were also found between ALFC and A body weight,?BMI,?WHA,?HbA1c(r=0.392,0.399,0.475 and 0.385,respectively;P=0.039,0.036,0.011 and 0.043,respectively).There was no significant correlation between theALFC andAFPG,TG,HDL-C.,LDL-C,SBP,DBP(r= 0.230,0.289,0187,0.326,0.152 and 0.193,respectively;P=0.240,0.135,0.340,0.091,0.212 and 0.325 respectively).Conclusion:Treatment with acarbose and lifestyle interventions can improve LFC in obese T2DM patients,and LFC can be used as an effective imaging biomarker to reflect not only body weight,BMI,waist circumference,WHR,HbAlc and LDL-C and to predict the change of body weight,waist circumference,BMI,WHR,and HbAlc during treatment in obese T2DM patients.