Influence of Gadoxetate disodium to the hepatic proton density fat fraction quantified with the Dixon sequences in a rabbit model

Objective To study the impact of Gx on quantification of hepatic fat contents under metabolic dysfunction-associated steatotic liver disease (MASLD) imaged on VIBE Dixon in hepatobiliary specific phase. Methods Forty-two rabbits were randomly divided into control group ( n = 10) and high-fat diet group ( n = 32). Imaging was performed before enhancement (Pre-Gx) and at the 13th (Post-Gx13) and 17th (Post-Gx17) min after Gx enhancement with 2E- and 6E-VIBE Dixon to determine hepatic proton density fat fractions (PDFF). PDFFs were compared with vacuole percentage (VP) measured under histopathology. Results 33 animals were evaluated and including control group ( n = 11) and MASLD group ( n = 22). Pre-Gx, Post-Gx13, Post-Gx17 PDFFs under 6E-VIBE Dixon had strong correlations with VPs ( r 2 = 0.8208—0.8536). PDFFs under 2E-VIBE Dixon were reduced significantly ( P < 0.001) after enhancement ( r 2 = 0.7991/0.8014) compared with that before enhancement ( r 2 = 0.7643). There was no significant difference between PDFFs of Post-Gx13 and Post-Gx17 ( P = 0.123) for which the highest consistency being found with 6E-VIBE Dixon before enhancement ( r 2 = 0.8536). The signal intensity of the precontrast compared with the postcontrast, water image under 2E-VIBE Dixon increased significantly ( P < 0.001), fat image showed no significant difference ( P = 0.754). Conclusion 2E- and 6E-VIBE Dixon can obtain accurate PDFFs in the hepatobiliary specific phase from 13 to 17th min after Gx enhancement. On 2E-VIBE Dixon (FA = 10°), effective minimization of T1 Bias by the Gx administration markedly improved the accuracy of the hepatic PDFF quantification.