Comparative diagnostic value of computed tomography and contrast-enhanced ultrasonography in diagnosis of focal liver lesions

Objective. The aim of the study was to evaluate focal liver lesions by computed tomography and contrast-enhanced ultrasonography and to compare their diagnostic values.
Materials and methods. There were 67 patients, examined and treated in the Departments of Gastroenterology, Surgery, and Oncology, Hospital of Kaunas University of Medicine, during 2007 (study group). All the patients underwent contrast-enhanced ultrasonography and bolus computed tomography. Control group included 73 patients with focal hepatic lesions who were examined and treated in the Hospital of Kaunas University of Medicine during 2006. Focal hepatic lesions were detected and characterized by conventional ultrasonography and bolus computed tomography. The diagnosis was confirmed by biopsy or during surgery in both groups, and hemangiomas were confirmed by magnetic resonance imaging. Patients’ age varied from 20 to 80 years (there were 46 [68.7%] women and 21 [31.3%] men with a mean age of 55.85±13.417 years). The age of patients in the study group varied from 18 to 91 years (mean age, 60.81±16.059 years; out of 73 patients, 46 [63%] were women and 27 [37%] men).
Results. The following was determined in the study group: hemangioma (n=18, 26.9%), focal nodular hyperplasia (n=4, 6%), adenoma (n=2, 3%), echinococcosis (n=2, 3%), hepatocellular carcinoma (n=11, 16.4%), cholangiocellular carcinoma (n=1, 1.5%), solitary metastasis (n=13, 19.4%), hepatic cyst (n=3, 4.5%), etc. The sensitivity and specificity of contrast-enhanced ultrasonography as compared with computed tomography in detecting and characterizing focal liver lesions was 44.2% and 46.7%, respectively; positive prognostic value was 74.2% and negative prognostic value was 19.4%. The sensitivity and specificity of conventional ultrasonography as compared with contrast-enhanced ultrasonography in detecting and characterizing focal liver lesions was 34.5% and 100%, respectively; positive prognostic value was 100% and negative prognostic value was 25%.
Conclusions. Ultrasound contrast agents (SonoVue, Bracco®, Milan, Italy) definitely improve detection and characterization of focal liver lesions. Ultrasonography correlates with computed tomography and magnetic resonance imaging, particularly during arterial phase. The sensitivity of contrast-enhanced ultrasonography as compared with computed tomography in detecting and characterizing focal liver lesions was 74.2% and positive prognostic value was 44.2%; sensitivity of conventional ultrasonography as compared with contrastenhanced ultrasonography in detecting and characterizing focal liver lesions was 34.5% and positive prognostic value was 100%.