RESUMO
BACKGROUND/AIMS: To assess the usefulness of magnetization-tagged magnetic resonance imaging (MRI) in quantifying cardiac-induced liver motion and deformation in order to predict liver fibrosis. METHODS: This retrospective study included 85 patients who underwent liver MRI including magnetization-tagged sequences from April 2010 to August 2010. Tagged images were acquired in three coronal and three sagittal planes encompassing both the liver and heart. A Gabor filter bank was used to measure the maximum value of displacement (MaxDisp) and the maximum and minimum values of principal strains (MaxP1 and MinP2, respectively). Patients were divided into three groups (no fibrosis, mild-to-moderate fibrosis, and significant fibrosis) based on their aspartate-aminotransferase-to-platelet ratio index (APRI) score. Group comparisons were made using ANOVA tests. RESULTS: The patients were divided into three groups according to APRI scores: no fibrosis (≤0.5; n=41), moderate fibrosis (0.5-1.5; n=23), and significant fibrosis (>1.5; n=21). The values of MaxDisp were 2.9±0.9 (mean±SD), 2.3±0.7, and 2.1±0.6 in the no fibrosis, moderate fibrosis, and significant fibrosis groups, respectively (P<0.001); the corresponding values of MaxP1 were 0.05±0.2, 0.04±0.02, and 0.03±0.01, respectively (P=0.002), while those of MinP2 were -0.07±0.02, -0.05±0.02, and -0.04±0.01, respectively (P<0.001). CONCLUSIONS: Tagged MRI to quantify cardiac-induced liver motion can be easily incorporated in routine liver MRI and may represent a helpful complementary tool in the diagnosis of early liver fibrosis.