Abstract
Background To investigate the value of liver ADC normalization using spleen as a reference organ in liver fibrosis assessment compared to Fibroscan. A total of 60 participants were included, 30 HCV positive patients and 30 in control group. We calculated mean spleen apparent diffusion coefficient (ADC), liver mean ADC, and normalized liver ADC (defined as the ratio of liver ADC to spleen ADC) which were compared between cirrhotic patients and the control group. Data was analyzed, and ROC was used to evaluate the performance of nADC. Results No significant difference between spleen ADC values of patient and control groups or in-between different fibrosis stages. A negative correlation between liver ADC and nADC values with increasing fibrosis stages. We also found that the mean liver ADC and nADC value in patients with hepatic fibrosis were significantly lower than that of control group (1.53 x 10(-3) mm(2)/s vs 1.65 x 10(-3) mm(2)/s). After analysis with ROC, nADC shows higher diagnostic performance compared to liver ADC. nADC area under the curve (AUC) was 0.878 for detection of stage >= F2 with sensitivity and specificity of 87% and 80% respectively while ADC AUC was 0.548 with sensitivity and specificity of 62% and 72% respectively (p= 0.021); >= F3 AUC of nADC was 0.891 with sensitivity and specificity of 88.7% and 80% respectively while ADC AUC is 0.603 with sensitivity and specificity of 72% and 72% respectively (p= 0.023), and F4 stage nADC AUC was 0.879 for with sensitivity and specificity of 90% and 80% respectively, while ADC AUC was 0.648 with sensitivity and specificity of 80% and 72% respectively (p= 0.054). Conclusion Normalized liver ADC using the spleen as reference organs increases the diagnostic performance of MR in evaluation liver fibrosis compared to ADC alone.