Diagnosis of Small Hepatocellular Carcinoma: Comparison of Low Mechanical Index Real-Time Contrast-Enhanced Ultrasonography with Contrast-Enhanced Helical CT

  • Rui Li, Department of Ultrasound, Southwest Hospital, the Third Military Medical University,, China
  • Xiao hang Zhang, Department of Ultrasound, Southwest Hospital, the Third Military Medical University,
  • Xing Hua, Department of Ultrasound, Southwest Hospital, the Third Military Medical University,

    • Objective: To compare the efficacy of real-time contrast- enhanced ultrasonography for the diagnosis of small hepatocellular carcinoma(≤2 cm) with contrast-enhanced CT.
    Methods: Low mechanical index (MI<0.19) real-time pulse-inversion harmonic SonoVue enhanced ultrasonography and contrast-enhanced helical CT were performed on 117 patients with small hepatocellular carcinoma[95 men and 22 women, age range 23~75 years, size of the nodules range 0.5~2.0 cm, mean size (1.43±0.34) cm]before operation or biopsy. The diagnostic performance was calculated by using histologic results as the reference standards.
    Results: Eleven cases were overlooked by contrast- enhanced ultrasonography and 27 cases were missed by contrast-enhanced CT. The detection rate of small HCC was 90.6 %(106/117) for contrast-enhanced ultrasonography and 76.9%(90/117) for contrast-enhanced CT (P<0.01). Taking hypervascular during arterial phase and washout during portal or late phase as the diagnostic criteria, overall diagnostic accuracy was 80.2%(85/106) for contrast- enhanced ultrasonography and 65.6%(59/90) for contrast-enhanced helical CT (P<0.05).
    Conclusion: Contrast-enhanced ultrasonography is superior to contrast-enhanced helical CT in detection and characterization of ≤2 cm small hepatocellular carcinoma and has high clinical value in patients whose contrast-enhanced CT scanning were negative.