LAUSR

AIM To evaluate the diagnostic performance of combining 18F-2-fluoro-2-D-deoxyglucose-positron emission tomography (18F-FDG PET) and gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for liver fibrosis staging. MATERIALS AND METHODS Male New Zealand white rabbits (n = 48) were treated with carbon tetrachloride (CCl4) to induce liver fibrosis, while control group rabbits (n = 8) received normal saline. The liver tissues of rabbits were histopathologically examined (classified according to the METAVIR classification system) for liver fibrosis staging and RT-PCR was used to ensure diagnostic accuracy. Integrated PET/MRI was performed. The mean standardised uptake value (SUVmean) and relative enhancement (RE) were evaluated for different liver fibrosis stages using a Mann-Whitney U test. The performance of PET/MRI was evaluated by using the receiver operating characteristic curve (ROC) and the area under the ROC curve (AUC). KEY FINDINGS In total, 10, 16, and 8 rabbits classified into no fibrosis (F0), mild fibrosis (F1-2), and severe fibrosis (F3-4) categories, respectively. There were significant differences in SUVmean and RE between F0 and F3-4 and between F1-2 and F3-4 (p < 0.01), but no significance between F0 and F1-2 (p > 0.5). Combined SUVmean and RE performed well in staging liver fibrosis, with AUC of 0.8 for F0 or greater, 0.744 for F0 or F1-2, 0.945 for F1-2 or F3-4, and 0.962 for F3-4. SIGNIFICANCE Combining SUVmean and RE provides high accuracy for grading liver fibrosis, especially in the differentiation between F1-2 and F3-4. 18F-FDG and Gd-EOB-DTPA-enhanced PET/MRI could be a non-invasive diagnostic method to guide the selection of clinical treatment options.