RESUMO
PURPOSE: To evaluate potential confounding factors in the quantitative assessment of liver fibrosis and cirrhosis using T1 relaxation times. METHODS: The study population is based on a radiology-information-system database search for abdominal MRI performed from July 2018 to April 2019 at our institution. After applying exclusion criteria 200 (59⯱â¯16 yrs) remaining patients were retrospectively included. 93 patients were defined as liver-healthy, 40 patients without known fibrosis or cirrhosis, and 67 subjects had a clinically or biopsy-proven liver fibrosis or cirrhosis. T1 mapping was performed using a slice based look-locker approach. A ROI based analysis of the left and the right liver was performed. Fat fraction, R2*, liver volume, laboratory parameters, sex, and age were evaluated as potential confounding factors. RESULTS: T1 values were significantly lower in healthy subjects without known fibrotic changes (1.5â¯T MRI: 575⯱â¯56â¯ms; 3â¯T MRI: 857⯱â¯128â¯ms) compared to patients with acute liver disease (1.5â¯T MRI: 657⯱â¯73â¯ms, pâ¯<â¯0.0001; 3â¯T MRI: 952⯱â¯37â¯ms, pâ¯=â¯0.028) or known fibrosis or cirrhosis (1.5â¯T MRI: 644⯱â¯83â¯ms, pâ¯<â¯0.0001; 3â¯T MRI: 995⯱â¯150â¯ms, pâ¯=â¯0.018). T1 values correlated moderately with the Child-Pugh stage at 1.5â¯T (pâ¯=â¯0.01, ρâ¯=â¯0.35). CONCLUSION: T1 mapping is a capable predictor for detection of liver fibrosis and cirrhosis. Especially age is not a confounding factor and, hence, age-independent thresholds can be defined. Acute liver diseases are confounding factors and should be ruled out before employing T1-relaxometry based thresholds to screen for patients with liver fibrosis or cirrhosis.