Assessment of tumor hemodynamics in small hepatocellular carcinoma: comparison of Doppler ultrasonography, angiography-assisted computed tomography, and pathological findings

Preoperative ultrasound features as prognostic factors for patients with hepatocellular carcinoma

PURPOSE

Ultrasound is the most common imaging tool used to scan the tumours of hepatic carcinoma patients. However, very few studies have been performed to evaluate ultrasound imaging features for predicting tumour prognosis. Therefore, the goal of the current study was to evaluate preoperative ultrasound characteristics as prognostic factors that could affect survival rate after liver resection for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

A total of 104 HCC patients who underwent resection were retrospectively reviewed with regard to their clinical data, preoperative ultrasound characteristics, and survival rate. Preoperative ultrasound parameters included cirrhosis, tumour site, size, echo pattern, portal vein thrombosis, intra-tumour blood flow signal, peak systolic velocity (V max), and resistance index (RI). The Kaplan-Meier method was used to calculate survival. Pre-resection prognostic factors were assessed using univariate log-rank test and a multivariate Cox proportional hazards model.

RESULTS

The median survival was 37 months. The 1-, 3-, and 5-year disease-free survival (DFS) rates were 78.85, 53.85, and 26.92 %, respectively, and the overall survival (OS) rates at 1, 3, and 5 years were 85.58, 69.23, and 46.15 %, respectively. On univariate analysis, shorter survival was associated with mixed echo pattern, larger tumour size, portal vein thrombus, affluent flow signal, and higher V max. Application of the Cox multivariate proportional hazards model indicated that tumour size and blood flow signal in the tumours were independent prognostic factors.

CONCLUSIONS

The overall survival for HCC patients undergoing hepatic resection can be stratified on a sonographic basis of tumour size and intra-nodular vasculature. These prognostic factors may be useful to determine appropriate treatment for HCC patients.

In vivo assessment of hepatic VX2 tumors in rabbits by real-time contrast-enhanced ultrasonography

AIM: To assess hepatic VX2 tumors in rabbits by real-time contrast-enhanced ultrasonography.

METHODS: Twenty-five New Zealand white rabbits were used to develop hepatic VX2 tumor-bearing rabbit models. Twenty-one days after hepatic VX2 tumor implantation, the rabbits underwent color Doppler ultrasonography and real-time contrast-enhanced ultrasonography after bolus injection of SonoVue via a peripheral vein. The dynamic features of the tumors and normal liver identified by contrast-enhanced ultrasound were summarized.

RESULTS: Tumor implantation was successful in 20 (80%) rabbits. 2-D ultrasound revealed isoechoic round-shaped lesions with a peripheral halo and low-level echoes implying central necrosis. CDFI could detect spot-like or strip-like blood echoes in the periphery or centre of the lesions. After injection of the contrast agent, the lesions gradually showed round or branched hyperechoic enhancement during the arterial phase, which gradually decreased with the increase in enhancement of liver parenchyma. The sensitivity, specificity, positive predictive value, and negative predictive value of contrast-enhanced ultrasound were 90.6%, 96.2%, 96.7%, and 86.7% for diagnosis of small hepatic tumors whose diameters were less than or equal to 3 cm. The sensitivity of contrast-enhanced ultrasound was 85.7% for diagnosis of minute hepatic tumors whose diameters were less than 1 cm.

CONCLUSION: Real-time contrast-enhanced ultrasonography permits differential diagnosis of small liver tumors by detecting dynamic tumor blood flow.

[Usefulness of contrast-enhanced ultrasonography in daily clinical practice: a multicenter study in Spain]

OBJECTIVES

We aimed to determine whether the use of ultrasonographic contrast agents improves the diagnostic performance of ultrasonography (US).

MATERIAL AND METHODS

We carried out a prospective multicenter study in 42 hospitals. We included 1786 patients with inconclusive US; 84.9% of the inconclusive studies were abdominal US (including studies of the liver, kidneys, spleen, and other sites), 6.2% were studies of the peripheral vessels, 4.3% were breast studies, and 4.6% were other studies. We evaluated the type of contrast-enhanced US (color Doppler or contrast-specific method), type of contrast agent, dose and number of doses, and type of administration (bolus or infusion). We evaluated whether the findings at contrast-enhanced US improved the diagnostic performance of unenhanced US and whether they enabled a conclusive diagnosis to be reached.

RESULTS

The contrast agent SonoVue was used in 99.9% of the studies; a single dose of contrast agent was used in 84.8%, and the contrast agent was administered in bolus in 98.5%. Contrast-enhanced US improved the diagnostic performance in 91.6% of cases and enabled the conclusive diagnosis in 69.2%. The best diagnostic performance was obtained in the supraaortic trunks, where a definitive diagnosis was reached in 95.4% of cases, followed by the abdominal area, with a conclusive diagnosis in 72.6% of cases.

CONCLUSIONS

The use of contrast-enhanced US significantly improved the diagnostic performance of US and enabled a conclusive diagnosis in most cases.

Contrast-enhanced ultrasound assessment of arterial vascularization of small nodules arising in the cirrhotic liver

BACKGROUND AND AIM

Aim of this study was to compare contrast-enhanced ultrasound and multi-detector row computed tomography in detecting arterial hypervascularity in small cirrhotic nodules.

PATIENTS AND METHODS

Sixty-two nodules (41 measuring 1.0-2.0 cm, 21 measuring 2.1-3.0 cm) found in 55 cirrhotic patients were examined with both methods. Lesions displaying arterial hypervascularity with washout in the portal/venous phase on both studies were considered hepatocellular carcinomas and treated; all other nodules were subjected to ultrasound-guided fine-needle biopsy.

RESULTS

The larger nodules (2.1-3.0 cm) included 19 hepatocellular carcinomas (90%), 1 macroregenerative nodule type I and 1 macroregenerative nodule type II; 35 (87%) of the smaller nodules were hepatocellular carcinomas, 2 were macroregenerative nodules type I, 2 macroregenerative nodules type II and 2 hemangiomas. The two studies yielded concordant findings for 54 nodules (87%), including 46 hypervascular on both examinations and 8 that were consistently hypovascular. Two of the latter nodules were hepatocellular carcinomas. The other eight nodules displayed arterial hypervascularity on only one of the studies. Six of these (75%) were hepatocellular carcinomas, including five that were negative in the contrast-enhanced ultrasound study.

CONCLUSION

Computed tomography and contrast-enhanced ultrasound show high agreement in the vascular classification of small nodules detected by ultrasound in cirrhotic livers, although the former technique was slightly more sensitive in the detection of arterial hypervascularization.

Cone-beam CT with flat-panel-detector digital angiography system: early experience in abdominal interventional procedures

We developed a cone-beam computed tomography (CBCT) system equipped with a large flat-panel detector. Data obtained by 200 degree rotation imaging are reconstructed by means of CBCT to generate three-dimensional images. We report the use of CBCT angiography using CBCT in 10 patients with 8 liver malignancies and 2 hypersplenisms during abdominal interventional procedures. CBCT was very useful for interventional radiologists to confirm a perfusion area of the artery catheter wedged on CT by injection of contrast media through the catheter tip, although the image quality was slightly degraded, scoring as 2.60 on average by streak artifacts. CBCT is space-saving because it does not require a CT system with a gantry, and it is also time-saving because it does not require the transfer of patients.

Small hepatic nodules (< or =2 cm) in cirrhosis patients: characterization with contrast-enhanced ultrasonography

AIM

We evaluated the efficacy of contrast-enhanced ultrasonography (CEUS) for the characterization of small hepatic nodules (< or =2 cm) in cirrhosis patients.

PATIENTS AND METHODS

Thirty cirrhosis patients with 30 hepatic nodules (1-2 cm) were enrolled in this study. Eighteen hepatic nodules were hepatocellular carcinomas (HCC) and 12 were benign lesions. CEUS was performed using microbubble contrast (Levovist). With surrounding hepatic parenchyma as a reference, two characteristics of hepatic nodules, including arterial phase enhancement (AE) and the absence of delayed phase enhancement (ADE), were evaluated as criteria for the diagnosis of HCC. A radiologist independently reviewed the dynamic computed tomographies (CT) of 26 hepatic nodules.

RESULTS

CEUS showed AE in 15 nodules (13 HCC and two benign) and ADE in 17 lesions (14 HCC and three benign). For HCC, the coincidental AE of both CEUS and dynamic CT was 40%. Using both AE and ADE for HCC diagnosis, the sensitivity, specificity, accuracy, positive predictive value and negative predictive values were 55.6%, 91.7%, 70%, 90.9% and 57.9%, respectively. When using either AE or ADE for HCC diagnosis, the same parameters were 94.4%, 66.7%, 83.3%, 81% and 88.9%, respectively. One benign hepatic nodule with both AE and ADE was diagnosed as HCC 29 months after the CEUS study.

CONCLUSIONS

A combination of characteristics of AE and ADE as determined by CEUS was highly specific for small HCCs in cirrhosis patients. Concurrent delayed phase imaging is useful in the diagnosis of small hypovascular HCCs.

Correlation between enhancement pattern of hepatocellular carcinoma on real-time contrast-enhanced ultrasound and tumour cellular differentiation on histopathology

The objective of this study was to evaluate the correlation between the enhancement pattern of hepatocellular carcinoma (HCC) on contrast-enhanced ultrasound (CEUS) and tumour cellular differentiation on histopathology. 189 HCC lesions in 189 patients were retrospectively evaluated with CEUS and histopathological examination. CEUS was performed with SonoVue and contrast pulse sequencing. Histopathological diagnoses were made according to the Edmonson grading system. Significant differences were shown between the time that the HCC became hypoenhancing or remained echogenic in late phase and tumour cellular differentiation (p = 0.006; p = 0.036), but not with the time of commencement of hyperenhancing or commencement of isoenhancing in arterial phase and portal phase (p = 0.164, p = 0.113; p = 0.186, p = 0.070). The timing of HCC becoming hypoenhancing on CEUS is correlated with tumour cellular differentiation; well differentiated tumours wash out more slowly than poorly differentiated ones.