The application value of mDIXON?Quant sequence in the quantification of liver and pancreatic iron deposition in blood transfusion?dependent diseases / 中华放射学杂志

ABSTRACT

Objective To explore the clinical value of mDIXON?Quant sequence in the quantitative evaluation of transfusion dependent patients with liver and pancreas iron deposition. Method Prospective collection of 34 transfusion dependent patients from December 2016 to May 2018 in Tianjin First Central Hospital who had not undergone iron chelation therapy was conducted in this study. According to the volume of blood transfusion,the subjects were divided into small amount of blood transfusion group (23 cases with blood transfusion of 2 000 to 5 000 ml within 3 years) and massive blood transfusion group (11 cases with blood transfusion of greater than 5 000 ml within 3 years). All patients underwent MR examinations using a Philips Ingenia 3.0 T MR scanner with multi?echo 3D?fast field echo (FFE) and 3D mDIXON?Quant protocols. For 3D multi?echo FFE images, the R2*(R2*=1/T2*) of liver and pancreas were calculated voxel by voxel. For mDIXON?Quant images,the dR2*(d R2*=1/dT2*),which was different from the R2*with 3D multi?echo FFE,was calculated within liver and pancreas voxel by voxel. Pearson correlation was performed to investigate the relationship between the R2*value and dR2*value of liver and pancreas in each group,and between the R2*(and dR2*) of liver and pancreas with the volume of blood transfusion. A paired ttest was used to compare the values of R2* and dR2* in the same patient. Results For small amount of blood transfusion group liver and pancreas R2* and dR2* values were significantly correlated with the correlation coefficients of 0.993 and 0.962 respectively. There was no correlation between the value of liver and pancreas and the amount of blood transfusion (P>0.05). There was no significant difference in R2*and dR2*values in liver and pancreas (P>0.05). For massive blood transfusion groupwhen T2*was smaller than 1.8 ms, the SNR of T2*maps was lower than that of dT2*maps, and the noise seriously affects the T2*measurements. When T2*was greater than 1.8 msliver and pancreas R2*and dR2*values were significantly correlated with the correlation coefficients of 0.991 and 0.989 respectively. Liver R2* and dR2* value were correlated with the volume of blood transfusion with the correlation coefficients of 0.527 and 0.639 respectively. Pancreas R2* and dR2* value were correlated with the volume of blood transfusion with the correlation coefficients of 0.590 and 0.602 respectively. There was statistical difference in R2*value of liver and dR2*value in paired t test (P<0.05),but there was no significant difference in R2*value of pancreas and dR2* value of pancreas (P>0.05). Conclusions Both multi?echo 3D FFE and mDIXON?Quant sequences can be applied for the evaluation of organ iron deposition.The mDIXON?quant sequence has advantages in heavy liver and pancreatic iron quantification