Normal hepatic parenchyma visibility and ADC quantification on diffusion-weighted MRI at 3 T: influence of age, gender, and iron content.

OBJECTIVES: To investigate how normal liver parenchyma visibility on 3 T diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) quantification are influenced by age, gender, and iron content.
METHODS: Between February 2011 and April 2013, 86 patients (52 women) with normal livers who underwent respiratory-triggered abdominal 3 T DWI (b = 0, 150, 600, 1,000 s/mm(2)) were retrospectively included. Normal liver and spleen parenchyma visibility was scored independently by two readers. Correlations between visibility scores or ADC with age, gender, T2*, or recent serum ferritin (SF) were investigated.
RESULTS: Liver visibility scores in b = 1,000 s/mm(2) images correlated with the age (Spearman R = -0.56 in women, -0.45 in men), T2* (R = 0.75) and SF (R = -0.64) and were significantly higher in women (P < 0.01). SF and T2* were within normal values (T2*: 13 - 31 ms, SF: 14 - 230 μg/L). Liver ADC correlated with visibility scores (R = 0.69) and T2* (R = 0.64) and was age- and gender-dependent. ADC ROI standard deviation negatively correlated with visibility scores (R = -0.65) and T2* (R = -0.62). The spleen visibility did not depend on age or gender.
CONCLUSIONS: Normal liver parenchyma visibility in DWI is age- and gender-dependent, according to the iron content. Visibility scores and iron content significantly affect ADC quantification in the normal liver. KEY POINTS: Normal DWI liver visibility is gender-dependent and superior in women. In women, normal DWI liver visibility is superior before age 50 years. Normal DWI liver visibility negatively correlates with normal range iron content markers. Liver ADC quantification depends on liver iron content even within normal range. Normal liver T2* is age- and gender-dependent.