Liver fibrosis assessment using 99mTc-GSA SPECT/CT fusion imaging

To determine the utility of mean standardized uptake value (SUV_mean) of whole liver measured by ^99mTc-GSA SPECT/CT fusion imaging, for evaluation of liver fibrosis.

Eighty-six patients who underwent hepatectomy were enrolled, and were classified into the non-fibrosis or fibrosis group based on the pathological findings in the resected liver specimen. Univariate and multivariate analyses were performed between the two groups on four blood biochemical indices (albumin, total bilirubin, platelet count, and prothrombin time activity) and two ^99mTc-GSA scintigraphy-derived liver function indices (LHL₁₅ and SUV_mean) to evaluate the independent predictive value for severe fibrosis. The diagnostic value of the index for severe fibrosis was assessed by calculating the area under the receiver operating characteristic curve.

Multivariate analysis showed that prothrombin time activity [odds ratio (OR) 0.519], LHL₁₅ (OR 0.513), and SUV_mean (OR 0.168) significantly correlated with liver fibrosis. SUV_mean showed the largest area under the curve, with value of 0.804, 0.730 for platelet count, 0.717 for LHL₁₅, and 0.668 for prothrombin time activity. The optimal cut-off value for SUV_mean was 6.7, which yielded 62.9% sensitivity and 96.9% specificity.

SUV_mean measured by ^99mTc-GSA SPECT/CT fusion imaging enables highly accurate prediction of severe liver fibrosis.