Depiction of vasculature in small hepatocellular carcinoma, and dysplastic nodules evaluated with carbon dioxide ultrasonography and angiography

Discrimination between neoplastic and non-neoplastic lesions in cirrhotic liver using contrast-enhanced ultrasound

OBJECTIVES

To assess the value of contrast-enhanced ultrasound (CEUS) in differentiating hepatocellular carcinoma (HCC) from non-neoplastic lesion in cirrhotic liver in comparison with baseline ultrasound.

METHODS

A total of 147 nodules (diameter ≤5.0 cm) in 133 cirrhotic patients (mean age±standard deviation: 52±13 years, range 20-82 years; gender: 111 males and 22 females) were examined with CEUS. There were 116 HCCs, 26 macroregenerative nodules and 5 high-grade dysplastic nodules. CEUS was performed with a real-time contrast-specific mode and a sulphur hexafluoride-filled microbubble contrast agent.

RESULTS

Hypervascularity was observed in 94.8% (110/116) HCCs, 3.8% (1/26) macroregenerative nodules and 60.0% (3/5) high-grade dysplastic nodules during arterial phase on CEUS. Detection rates of typical vascular pattern (i.e. hypervascularity during arterial phase and subsequent washout) in HCCs with a diameter of ≤2.0 cm, 2.1-3.0 cm and 3.1-5.0 cm were 69.2% (27/39), 97.1% (33/34) and 100.0% (43/43), respectively. CEUS significantly improved the sensitivity [88.8% (103/116) vs 37.1% (43/116), p<0.001], negative predictive value [70.5% (31/44) vs 31.5% (29/92), p<0.001], and accuracy [91.2% (134/147) vs 49.0% (72/147), p<0.001] in differentiating HCCs from non-neoplastic lesions when compared with baseline ultrasound. However, the sensitivity and accuracy of CEUS for HCCs ≤2.0 cm in diameter were significantly lower than those for HCCs of 2.1-3.0 cm and 3.1-5.0 cm in diameter.

CONCLUSIONS

CEUS improves diagnostic performance in differentiating HCCs from non-neoplastic nodules in cirrhotic patients compared with baseline ultrasound. Diagnosis of HCCs ≤2.0 cm diameter by CEUS is still a clinical concern, and thus needs further investigation.

Contrast-enhanced sonography in the diagnosis of small hepatocellular carcinoma < or =2 cm

PURPOSE

To evaluate the usefulness of contrast-enhanced sonography (CEUS) in the diagnosis of small hepatocellular carcinoma (HCC) measuring < or =2 cm in diameter.

METHODS

We identified 104 focal liver lesions measuring < or =2 cm in 104 consecutive patients who were enrolled for baseline sonography (BUS) and CEUS examination (49 HCCs, 55 non-HCCs). A real-time, contrast-specific mode of contrast pulse sequencing and a sulphur hexafluoride-filled microbubble contrast agent were used for CEUS. The diagnostic performances of BUS and CEUS in differentiating focal liver lesions (HCC or non-HCC) were analyzed and compared.

RESULTS

On CEUS, 43 (87.8%) of the 49 HCC lesions were hyperenhanced, 5 (10.2%) were isoenhanced, and 1 (2%) was hypoenhanced during the arterial phase when compared with adjacent liver tissue. Thirty-nine (79.6%) HCCs exhibited washout from the portal phase to the late phase. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy before and after contrast agent administration were 28.6% (14/49) versus 79.6% (39/49) (p < 0.001), 94.5% (52/55) versus 92.7% (51/55) (p > 0.05), 82.4% (14/17) versus 90.7% (39/43) (p > 0.05), 59.8% (52/87) versus 90.7% (39/43) (p < 0.01), and 63.5% (66/104) versus 86.5% (90/104) (p < 0.001), respectively. No significant difference in diagnostic performance of CEUS was found between lesions measuring < or =1.5 cm and those 1.6-2 cm and between lesions located at a depth of < or =6 cm from the skin and those located deeper.

CONCLUSIONS

CEUS significantly improved the diagnostic performance in characterization of small HCCs < or =2 cm compared with BUS.