Feasibility and accuracy of quantification of fat content using iterative decomposition of water and fat with asymmetry and least squares estimation-quantitative fat imaging：a phantom study
10.3760/cma.j.issn.1005-1201.2015.09.014
- VernacularTitle:采用基于最小二乘法估计和不对称回波迭代分解水和脂肪成像序列定量评估水-脂模型中脂肪含量的可行性和准确性
- Author:
Xiao CHEN
;
Xiaoyan MENG
;
Xiaojuan LI
;
Zhen LI
;
Yaqi SHEN
;
Daoyu HU
- Publication Type:Journal Article
- Keywords:
Lipids;
Magnetic resonance imaging;
Comparative study
- From:
Chinese Journal of Radiology
2015;(9):704-707
- CountryChina
- Language:Chinese
-
Abstract:
Objective To validate the feasibility and accuracy of iterative decomposition of water and fat with asymmetry and least squares estimation-quantitative fat imaging (IDEAL-IQ) in fat quantification using fat-water model. Methods A homogeneous fat-water mixture model consisting of various known fat-fractions were described, and the fat fraction was 0.00, 0.01, 0.02, 0.04, 0.06, 0.08, 0.10, 0.14, 0.18, 0.22, 0.26, 0.30 g/ml respectively. A water-vaseline separated model was also described. IDEAL-IQ was performed. Thin slices were acquired for fat-water mixture model and repeated 3 days later. Nineteen slices of 14 mm-thick parallel to the water-vaseline boundary in 1 mm steps from vaseline to water
were acquired. The fat-fractions in 11 slices of fat-water mixture model were measured on FatFrac images. Accuracy was assessed through single sample t test or Kolmogorov-Sirmov test. Measured fat-fractions of the same known fat-fraction were assessed through independent samples t test between two scan times. Linear regression was used to assess the relationship between known fat-fractions and measured fat-fractions. Slices containing the water-vaseline boundary were measured with ROI in the middle of the FatFrac images. The relationship between measured fat-fractions and locations of scanning was exploded using curve fitting. Results (1) Fat-water mixture model: no significant difference(P>0.05) was found between measured fat-fractions and known fat-fractions when it was 0.00, 0.02, 0.06 and 0.08 g/ml with the measured fat-fractions 0.60%, (2.30 ± 0.60)%, (5.76 ± 1.40)%, (7.62 ± 1.40)% respectively for the first time. No significant difference(P>0.05) was found between measured fat-fractions and known fat-fractions when it was 0.00, 0.02, 0.10 g/ml with the measured fat-fractions 0.04%, (2.32 ± 0.60)%, (9.41 ± 1.00)%respectively for the second time. Measured fat-fraction was inlinear relation with known fat-fraction:Y=0.898X+0.224, r2=0.993, P<0.01, F=36 129.548.(2) Water-vaseline separated model: measured fat-fraction increased as scanning location changed, Y=0.045X2-0.499X-4.474, r2=0.978, P<0.05, F=350.623.Conclusions IDEAL-IQ can be used to quantify fat content with good repeatability and can accurately assess the actual fat content from the linearrelationship.
