To evaluate the diagnostic value of dual-detector spectral CT in early primary liver cancer (PLC).

60 patients with PLC and/or cirrhosis admitted to the Third Affiliated Hospital of Sun Yat-sen University were enrolled in this study. The informed consents of all patients were obtained and the local ethical committee approval was received. Among them, 49 patients were male and 11 female, aged from 50 to 70 years, with a median age of 57 years. The diameter of liver cancer was 1.2-3.0 cm, with a median diameter of 1.8 cm. 21 patients had a single lesion and 9 cases of multiple lesions. All patients received by dual-detector spectral enhanced CT. After CT scan, virtual 40 keV single-energy enhanced CT images, iodine density enhanced CT images and effective atomic number enhanced CT images were reconstructed. The suspected patients further received MRI. The results were evaluated by two radiologists experienced in liver cancer diagnosis by double-blind method. Pathological examination was considered as the diagnostic gold standard. The diagnostic rates of three imaging methods or the combined for early PLC were assessed by Chi-square test. The diagnostic value was analyzed by the area under the ROC curve (AUC).

Pathological examination showed that 30 patients were diagnosed with early PLC and 30 cases of liver cirrhosis. The diagnostic rate for early PLC by 120 kV conventional CT images was 63%(19/30), including 11 suspected patients diagnosed by MRI. The diagnostic rate of virtual 40 keV single-energy enhanced CT images for early PLC was 67%(20/30), 80%(24/30) for the iodine density enhanced CT images, 83%(25/30) for the effective atomic number enhanced CT images, and 93%(28/30) for the combination of three images, respectively. Compared with single use of three enhanced CT images, the diagnostic rate of the three combined was significantly enhanced (χ²=17.37, 5.43, 4.01; P<0.05). ROC curve analysis showed that the AUC of three images and the three combined was 0.638, 0.760, 0.782 and 0.904, respectively. The diagnostic value of the three combined was the highest.

The combination of three dual-detector spectral CT images yields a high diagnostic rate for early PLC, which can assist physicians to promptly identify PLC lesions, and improve therapeutic effect and clinical prognosis.