Evaluation of Liver Metastases Using Contrast-Enhanced Ultrasound: Enhancement Patterns and Influencing Factors

BACKGROUND/AIMS: To evaluate the enhancement patterns of liver metastases and their influencing factors using dynamic contrast-enhanced ultrasound (CEUS). METHODS: A total of 240 patients (139 male and 101 female; 58.5±11.2 years of age) diagnosed with liver metastases in our hospital were enrolled in this study to evaluate tumor characteristics using CEUS. A comparison of enhancement patterns with tumor size and primary tumor type was performed using the chi-square test. The differences between quantitative variables were evaluated with the independent-sample t-test and one-way analysis of variance. RESULTS: The enhancement patterns of liver metastases on CEUS were categorized as diffuse homogeneous hyperenhancement (133/240, 55.4%), rim-like hyperenhancement (80/240, 33.3%), heterogeneous hyperenhancement (10/240, 4.2%), and isoenhancement (17/240, 7.1%). There were significant differences in the enhancement patterns during the arterial phase based on the nodule size (p=0.001). A total of 231 of the nodules showed complete washout during the portal phase, and 237 nodules were hypoenhanced during the delayed phase. The washout time was correlated with tumor vascularity, with a longer washout time observed in hypervascular metastases compared to hypovascular metastases (p=0.033). CONCLUSIONS: Diffuse homogeneous hyperenhancement followed by rapid washout was the most common enhancement pattern of liver metastases on CEUS and was affected by the nodule size and tumor vascularity. Small metastases were prone to show diffuse homogeneous hyperenhancement. Hyper-vascular metastases showed a significantly longer washout time compared to hypovascular metastases.

Qualitative and Quantitative Analysis with Contrast-Enhanced Ultrasonography: Diagnosis Value in Hypoechoic Renal Angiomyolipoma

OBJECTIVE: To evaluate the value of enhancement features and quantitative parameters of contrast-enhanced ultrasonography (CEUS) in differentiating solid hypoechoic renal angiomyolipomas (AMLs) from clear cell renal cell carcinomas (ccRCCs). MATERIALS AND METHODS: We analyzed the enhancement features and quantitative parameters of CEUS in 174 hypoechoic renal masses (32 AMLs and 142 ccRCCs) included in the study. RESULTS: Centripetal enhancement pattern was more common in AMLs than in ccRCCs on CEUS (71.9% vs. 23.2%, p < 0.001). At peak enhancement, all AMLs showed homogeneous enhancement (100% in AML, 27.5% in ccRCCs; p < 0.001). Quantitative analysis showed no significant difference between rise time and time to peak. Tumor-to-cortex (TOC) enhancement ratio in AMLs was significantly lower than that in ccRCCs (p < 0.001). The criteria of centripetal enhancement and homogeneous peak enhancement together with TOC ratio < 91.0% used to differentiate hypoechoic AMLs from ccRCCs resulted in a sensitivity and specificity of 68.9% and 95.8%, respectively. CONCLUSION: Both qualitative and quantitative analysis with CEUS are valuable in the differential diagnosis of hypoechoic renal AMLs from ccRCCs.

Diagnosis of atypical liver abscesses with real-time contrast-enhanced ultrasound / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the value of real-time harmonic contrast-enhanced ultrasound (CEUS) in the diagnosis of atypical liver abscesses.</p><p><b>METHODS</b>We used Technos DU8 system with CEUS technique to examine 32 patients with suspected liver masses. Mechanical index was set at 0.08- 0.11. The contrast agent SonoVue was injected as a bolus (2.4 ml, < 5s) in the antecubital vein.</p><p><b>RESULTS</b>A total of 36 lesions were studied in 32 patients, including 30 patients with single nodule and 2 patients with multiple nodules. All lesions with liver abscess were confirmed by biopsy. The whole-enhanced pattern in all lesions was clearly displayed in the arterial phase after the administration of SonoVue. The mean time of the beginning enhancement was (14.48 +/- 3.62) s, the mean peak enhancement time was (22.92 +/- 4.35) s, and the mean time of hypoechoic appearance of lesion was (80.30 +/- 35.30) s. The lesions with hypoechoic pattern (37.5%, 12/32) and isoechoic pattern (62.5%, 20/32) in the portal phase were detected by CEUS. The characteristic sign with honeycomb pattern on CEUS was shown in 30 (93.8%) liver abscess lesions.</p><p><b>CONCLUSION</b>CEUS is valuable in the diagnosis of atypical liver abscesses.</p>