Quantitative analyses of cardiac CT plain scan versus CT angiography in assessing epicardial fat volume

  Objective  To compare the clinical effect of quantitative analysis of CT plain scan and CT angiography (CTA) in assessing epicardial fat volume.

  Methods  A total of 170 patients with coronary heart disease were selected as study objects, and underwent cardiac CT plain scan and CTA examination at the same period. After uploading the original images to the workstation, patients' heart images were reconstructed based on optimal R-R interphase, and outline of the pericardium was automatically drawn. Epicardial adipose tissue was extracted; volume enhancement tools were used to measure and calculate fat volume; the operation was performed by two senior radiographic physicians using double blind methods. CT plain scan and CTA were used to determine the consistency of measured results of epicardial fat volume.

  Results  Volume of epicardial fat measured by CT was (99.59±43.14) cm², and was (94.05±45.70) cm³ by CTA, the difference was not statistically significant (P>0.05). Linear regression analysis showed that there was a significant positive correlation between consistency of CT plain scan and that of epicardial fat volume CTA determined by two physicians (R_A²=0.942, R_B²=0.947). Bland-Altman analysis showed that the repetition coefficient errors of CT scan and CTA were 9.45(95%CI, 7.83 to 10.62) cm³ and 7.68 (95%CI, 6.71 to 7.93) cm³, respectively. The correlation coefficient in CT plain scan group was 0.95(95%CI, 0.94 to 0.96), and was 0.96(95%CI, 0.95 to 0.97) in the CTA group, and they had good consistency.

  Conclusion  Both cardiac CT flat scan and CTA can be used to evaluate the fat volume of the external cardiac membrane, and they both have good consistency in quantitative analysis results, therefore they can be selected according to the actual situations.