Hepatic tumors: contrast agent-enhancement patterns with pulse-inversion harmonic US.

Area of Science:

• Medical Imaging
• Hepatology
• Radiology

Background:

• Distinguishing benign hepatic hemangiomas from malignant liver lesions like metastases and hepatocellular carcinomas (HCCs) is crucial for patient management.
• Conventional ultrasonography (US) can be limited in characterizing focal liver lesions.

Purpose of the Study:

• To assess the diagnostic utility of pulse-inversion harmonic ultrasonography (PIH-US) with a microbubble contrast agent.
• To evaluate and compare contrast-enhancement patterns of hepatic hemangiomas, metastases, and HCCs using PIH-US.

Main Methods:

• Sixty-one hepatic lesions (20 hemangiomas, 33 metastases, 8 HCCs) were examined using PIH-US.
• A microbubble contrast agent (SH U 508A) was administered as a bolus, and dynamic imaging was performed for 5 minutes.
• Contrast-enhancement patterns, including peripheral, globular, rimlike, homogeneous, stippled, and centripetal fill-in, were analyzed.

Main Results:

• Hemangiomas predominantly showed peripheral, globular, or rimlike enhancement with centripetal fill-in (95%).
• Malignant lesions (metastases and HCCs) exhibited varied patterns including rimlike, homogeneous, stippled, or heterogeneous enhancement, with no centripetal fill-in observed.
• No enhancement was detected in 24% of metastases.

Conclusions:

• PIH-US with microbubble contrast agents demonstrates significant potential for the specific diagnosis of hepatic hemangiomas.
• Characteristic enhancement patterns observed with PIH-US aid in differentiating hemangiomas from malignant liver tumors.