CT and MRI improve detection of hepatocellular carcinoma, compared with ultrasound alone, in patients with cirrhosis.

BACKGROUND & AIMS In patients with cirrhosis, hepatocellular carcinoma (HCC) is detected by ultrasound (US), computed tomography (CT), or magnetic resonance imaging (MRI); US is recommended for screening and surveillance. We performed a retrospective analysis of the abilities of these cross-sectional imaging modalities to detect HCC. METHODS We analyzed data from 638 consecutive adult patients with cirrhosis who received liver transplants within 6 months of imaging at a tertiary care institution. Imaging reports and serum alpha-fetoprotein levels were compared with results from pathology analysis of explants as the reference standard. Sensitivities of US, CT, and MRI were calculated overall and in defined size categories. False-positive imaging results and patient-based specificities were evaluated. RESULTS Of the 638 patients, 225 (35%) had HCC, confirmed by pathology analysis of liver explants. In 23 cases, the lesions were infiltrative or extensively multifocal. In the remaining 202 explants (337 numerable, discrete nodules), respective lesion-based sensitivities of US, CT, and MRI were 46%, 65%, and 72% overall and 21%, 40%, and 47% for small (<2 cm) HCC. The sensitivity of US increased with the availability of CT or MRI data (P = .049); sensitivity values were 62% and 85% for lesions 2-4 and ≥ 4 cm, respectively. Patient-based specificities of US, CT, and MRI were 96%, 96%, and 87%, respectively. CONCLUSIONS US, CT, and MRI did not detect small HCC lesions with high levels of sensitivity, although CT and MRI provide substantial improvements over unenhanced US in patients with cirrhosis who received liver transplants.