Effectiveness Evaluation of the Fat Percentage Determination in Multi-Echo T2-Corrected Single-Voxel Spectroscopy by Comparing the 3-Point Dixon and the 6-Point Interference Dixon Techniques

Abstract

This study compared fat percentage in the HISTO method and chemical-shift imaging method, a 3-echo 3D gradient echo sequence with a T2*-corrected Dixon (3-point Dixon) and 6-echo interference Dixon magnetic resonance (MR) imaging (6-point Dixon) method, to evaluate clinical significance of fatty liver quantification by multi-echo T2*-corrected single-voxel spectroscopy Histo (HISTO). A total of 21 liver donors underwent MR imaging examination. The 3-T MR system (Siemens Healthcare Tim Verio, Erlangen, Germany) was used for all studies. For fat percentage evaluations, a 3-echo 3D gradient echo sequence with T2*-corrected Dixon (3-point Dixon) and 6-Echo Interference Dixon (6-point Dixon) pulse sequences, including HISTO, were applied in sequence. Using fat percentages obtained from each pulse sequence, levels of fatty liver were classified as: non-fatty liver, <5 %; mild fatty liver, >5 but <31 %; and severe fatty liver, >31 %. The correlation between methods was calculated with a correlation coefficient (R ²): HISTO and 3-point Dixon, 0.936 (p < 0.001); HISTO and 6-point Dixon, 0.944 (p < 0.001); and 3-point Dixon and 6-point Dixon, 0.984 (p < 0.001). The HISTO, which was used to investigate fat percentages after T2* correction, showed a high correlation with 3-point Dixon and 6-point Dixon, suggesting that the multi-echo method is useful for accurately determining fat percentages.