Differentiating hepatocellular carcinoma from angiomyolipoma of the liver with CT spectral imaging: A preliminary study

Aim: To investigate the value of computed tomography (CT) spectral imaging in differentiating hepatocellular carcinoma (HCC) from angiomyolipoma (AML) during the arterial phase (AP) and portal venous phase (PP). Materials and method: Fifty-three patients underwent spectral CT during the AP and PP. Forty-five patients had 45 HCC and eight patients had eight AML. Iodine concentrations in the lesions were normalized to those of the aorta. The normalized iodine concentrations (NIC) and the lesion-normal parenchyma iodine concentration ratio (LNR) were calculated. The two-sample t-test was performed to compare quantitative parameters. Two readers qualitatively assessed lesion types on the basis of imaging features. Sensitivity and specificity were compared between the qualitative and quantitative studies. Results: NICs and LNRs in patients with HCC differed significantly from those in patients with AML: mean NICs were 0.25 ± 0.06 mg/ml versus 0.59 ± 0.03 mg/ml, respectively, during the AP and 0.52 ± 0.12 mg/ml versus 0.78 ± 0.03 mg/ml, respectively, during the PP. Mean LNRs were 2.97 ± 0.42 versus 5.85 ± 0.43, respectively, during the AP and 0.99 ± 0.17 versus 1.36 ± 0.05, respectively, during the PP. The NICs and LNRs for HCC were lower than those of AML during the AP and PP. The differences were significant (p < 0.05). The threshold NIC and LNR had high sensitivity and specificity in differentiating HCC from AML. Conclusion: CT spectral imaging with the quantitative analysis of iodine concentration may help increase the accuracy of differentiating HCC from AML