Comparison between tissue harmonic imaging and liver-specific late-phase contrast-enhanced pulse-inversion imaging in the detection of hepatocellular carcinoma and liver metastasis.

PURPOSE

To assess whether liver-specific late-phase contrast-enhanced pulse-inversion (CE-PI) ultrasound imaging improves the detection of hepatocellular carcinoma (HCC) and liver metastasis in comparison with non-enhanced tissue harmonic imaging (THI).

SUBJECTS AND METHODS

Twenty-one patients with HCC or liver metastasis were studied using standardized ultrasound harmonic settings. Sweeps through the hepatic lobes were done by THI, followed by late-phase CE-PI after Levovist injection. The number and segmental location of nodules detected by each method were recorded and compared with dynamic helical computed tomography (CT) as a reference.

RESULTS

Sensitivity for the presence of the disease, metastasis or HCC, on a patient basis for each method was 81.0% for THI and 90.5% for CE-PI. Among the 78 metastatic nodules on reference CT, 31 true-positive, three false-positive, and 47 false-negative nodules were found by THI, while CE-PI depicted 54 true-positive, 12 false-positive and 24 false-negative lesions. Sensitivity in the detection of individual lesion was 51.8% for THI and 76.8% for CE-PI (p=0.0273). A total of 58 HCC nodules were detected on CT; 36 true-positive, 15 false-positive, and 22 false-negative lesions were found by THI; while CE-PI depicted 43 true-positive, six false-positive, and 15 false-negative lesions. Sensitivity in the detection of individual HCC was 42.9% by THI and 57.2% by CE-PI (p=0.2249 NS).

CONCLUSION

In patients with liver metastasis, CE-PI statistically improved the sensitivity of lesion detection compared with THI. Conversely, CE-PI did not improve the sensitivity of lesion detection in patients with HCC.