| Part 1The influence of ROI size on quantitative study of liver and pancreas fat was evaluated based on IDEAL-IQBackgroundHistopathology has long been the gold standard for accurate assessment of fat content in the liver and pancreas.However,due to the increased risk of needle biopsy and sampling error,it cannot be routinely used in clinical practice.The Ideal-IQ technique is an improved 3-point Dixon technique that uses 3-D fast multi-echo gradient imaging sequences.By reducing the influence of confounding factors,such as T2 attenuation and the multispectral peak distribution of fat,the technique can finally generate accurate quantitative image fat ratio and R2*fat map to quantitatively evaluate the fat content of the organs.The regions of interest(ROI)can be used to measure the fat content accurately and quantitatively,that is,the proton density fat fraction(PDFF).The so-called ROI refers to that in the process of image processing,the area that needs to be studied is outlined by means of square box,circle,ellipse,irregular polygon,etc.,and the organization within this range is studied separately.In the measurement of fat in different tissues,whether the ROI size has an impact on the final results is a question that we need to study,and also provides a reliable methodological basis for further evaluation of liver and pancreatic fat content in patients with schizophrenia.ObjectiveTo investigate the reproducibility of different ROI in the quantification of liver and pancreas fat content in IDEAL-IQ.MethodsEighty-volunteers were included in the study.Two physicians independently measured the ROI of the right lobe of the liver for three times(90～110mm~2,190～210mm~2,290～310mm~2),and the head,body and tail of the pancreas for three times(70～90mm~2,120～140mm~2,170～190mm~2).Two weeks after the first measurement,the measurements were taken again without reference to the previous measurements.Analysis of variance was used to compare the differences of PDFF values measured by the same surveyor in the same position and under different ROI areas.The intra-group correlation coefficient(ICC)was used to evaluate the repeatability of PDFF values measured at the same location and the same ROI area with the same observer interval of two weeks.The Bland-Altman method was used to evaluate the consistency of PDFF values measured by two observers at the same location and the same ROI area.Results1.Liver measurement:When the two physicians respectively measured the liver,different ROI was selected,namely,pair comparison of PDFF values measured when the ROI area was 90～110mm~2,190～210mm~2 and 290～310mm~2.The difference was not statistically significant(p>0.05),and the results were reproducibility.The two physicians were separated by two weeks,and the ICC in the same position and the same ROI area was higher,and the consistency was good.2.Pancreas measurement:the pancreatic body and pancreatic tail were measured by two physicians respectively,and the differences of PDFF values under ROI of 120～140mm2and 170～190mm2,70～90mm2 and 170～190mm2 were statistically significant(p<0.05).Two physicians were separated for two weeks,and the ICC in the same position and the same ROI area was higher.The consistency of the measurement of the pancreas and the pancreas head was good when the ROI was between70～90mm~2,120～140mm~2 and 170～190mm~2.Conclusions1.The choice of ROI size had no significant effect on the results of Ideal-IQ liver fat quantification.2.The selection of ROI size affects the quantitation of pancreatic fat content with IDEAL-IQ:the reproducibility is better when the ROI area is between 70～90mm~2 and120～140mm~2.Part 2 Quantitative assessment of fat in liver and pancreas and analysis of related risk factors in patients with comorbid metabolic syndrome in schizophrenia with IDEAL-IQ.BackgroundSchizophrenia is a chronic and complex severe mental disorder with gradual loss of social function.It shows significant abnormalities in cognitive,emotional,behavioral and other mental activities,which further damages social function and leads to heavy burden on the sick family.Compared with normal group,the negative symptoms of schizophrenia patients due to disease itself lack of motivation,emotional indifference and antipsychotic drugs long-term sedation exercise reduce greatly,can also lead to patients,in turn,increase risk of obesity,so schizophrenia patients with metabolic syndrome(MS)risk is much higher than the general population.In schizophrenia with metabolic syndrome,the main clinical manifestations of patients are abdominal obesity,dyslipidemia,elevated blood sugar,and hypertension.Therefore,the risk of developing cardiovascular disease and type 2 diabetes is also significantly increased,which becomes one of the main reasons for the poor prognosis of schizophrenia.Therefore,early identification,early management,regular monitoring and prevention of metabolic syndrome in patients with comorbidities in schizophrenia are of great significance,which directly determines the prognosis,quality of life and recovery of social function in patients with schizophrenia.Previous studies have shown that ectopic fat deposition is closely related to metabolic syndrome.Compared with general obesity,ectopic fat deposition in liver,pancreas and other viscera is the key to the occurrence and development of the disease.Therefore,the accurate quantification of liver and pancreatic fat is of great significance for the early identification of the risk of metabolic syndrome in patients with schizophrenia,early treatment and examination,and for the prognosis of the disease.ObjectiveTo explore the changes of liver and pancreatic fat content in patients with schizophrenia and metabolic syndrome,and to study the correlation between liver and pancreatic fat content and other related clinical indicators.MethodsA total of 100 schizophrenic patients(54 males and 46 females,aged 21-45 years)who underwent abdominal IDEA-IQ scanning in our hospital were enrolled.There were 43 patients in the observation group(combined with MS)and 57 patients in the control group(without MS).PDFF values in the liver and pancreas(average values of the head,body and tail of the pancreas)were measured.Non-parametric tests were used to compare the PDFF values of liver and pancreas fat,Weight,body mass index(BMI),triglyceride(TG),fasting blood glucose(FPG),Age and Height between the two groups.Spearman rank correlation coefficient was used for non-normal distribution data to analyze the correlation between liver and pancreatic fat content and whether there was correlation between liver and pancreatic fat content and age,BMI,FPG and TG,respectively.Results1.The control group in the liver,pancreas,adipose PDFF values were 4.90(4.49,5.25)%,3.33(2.06,4.09)%,observation group of liver,pancreas and adipose PDFF values were 15.74(11.78,16.71)%,10.01(8.17,11.11)%,liver,pancreas,adipose content observation group were higher than that of control group,two groups between the liver and pancreas PDFF value differences statistically significant,p < 0.05).2.There was a positive correlation between the PDFF values of liver and pancreas in the control group(r=0.362,P =0.006).There was a positive correlation between PDFF values of liver and pancreas in the observation group(r=0.771,P =0.000).3.Weight,BMI,TG and FPG in the control group were all lower than those in the observation group,and the differences were statistically significant;The Age and Height P > 0.05 between the control group and the observation group were not statistically significant.4.Liver fat content in the observation group was positively correlated with BMI(r=0.537,P =0.001),TG(r=0.462,P =0.002)and FPG(r=0.859,P =0.000);The pancreatic fat content in the observation group was positively correlated with BMI(r=0.409,P =0.001),TG(r=0.307,P =0.045)and FPG(r=0.794,P =0.000).In the control group,pancreatic fat content was positively correlated with TG(r=0.708,P =0.000).Conclusions1.The fat content in liver and pancreas was significantly increased in patients with schizophrenia comorbidity MS.2.There was a positive correlation between the liver and pancreas fat content(PDFF)in the observation group and the control group,but the correlation was more obvious when MS was comorbid with schizophrenia.3.In schizophrenia comorbidity MS,the fat content of liver and pancreas was positively correlated with triglyceride,fasting blood glucose and BMI. |
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