Spleen size measured on enhanced mri for quantitatively staging liver fibrosis in minipigs

Purpose: To investigate whether and how spleen size measured on magnetic resonance imaging (MRI) could be used to stage liver fibrosis. Materials and Methods: Sixteen minipigs were used to prospectively model liver fibrosis staged by biopsy. Abdominal gadolinium-enhanced MRI was performed on the 0, 5th, 9th, 16th, and 21st weekend after beginning of the modeling. Splenic maximal width (W), thickness (T), length (L), and area (S) together with spleen volume (SV) and liver volume (LV) were measured on enhanced MRI and the ratio of SV to LV (SV/LV) was calculated. Spleen multidimensional indexes 1 and 2 were obtained by W x T x L and S x L, respectively. Statistical analyses were performed to determine which parameter could best stage the fibrosis. Results: W, T, L, S, SV, index 1 and 2, and SV/LV tended to increase with increasing stages of fibrosis (r = 0.46-0.796, all P < 0.001), and might predict liver fibrosis stage 1, 2, 3, and 4 (area under receiver operating characteristic curve [AUC] = 0.697-1.0, all P < 0.05). Among the parameters, splenic index 1, SV, and SV/LV might be best for predicting stage 1 (AUC = 0.941), 2 or 3 (AUC = 0.875 or 0.978, respectively), and 4 (AUC = 1.0), respectively. Conclusion: Spleen size measured on MRI could be used for staging liver fibrosis. J. Magn. Reson. Imaging 2013;38:540-547. (c) 2013 Wiley Periodicals, Inc.