New perspectives for the use of contrast-enhanced liver ultrasound in clinical practice

Evaluation of the Time Difference Method in Identifying Hepatocellular Carcinoma in Current CEUS LR-M Category Nodules

OBJECTIVE

The aim of the work described here was to explore a potential method for improving the diagnostic detection of hepatocellular carcinoma (HCC) based on the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) Version 2017.

METHODS

We retrospectively evaluated 585 liver nodules in 427 patients at risk for HCC from December 2020 to March 2023. The nodules were categorized as LR-1 to LR-M based on CEUS LI-RADS Version 2017 and were randomly subclassified into a developmental cohort (DC) and a validation cohort (VC) at 3:1. In the DC, the cutoff value of the time difference (∆T) for differentiating HCC from other malignancies by LR-M was calculated and used to reclassify nodules in the VC. The diagnostic effect on HCC detection before and after reclassification was further assessed.

RESULTS

According to the current CEUS LI-RADS, 140 of 426 (32.9%) confirmed HCC nodules were misclassified as LR-M. In the DC (439 nodules), the receiver operating characteristic (ROC) curve revealed that the cutoff value of ∆T (wash-out onset time minus contrast arrival time) recommended for HCC diagnosis was greater than 21 s. In the VC (146 nodules), 34 HCCs were correctly categorized as LR-5 according to the cutoff value, and after reclassification, LR-5 had higher accuracy (67.1% vs. 89.0%, p < 0.001) and sensitivity (56.0% vs. 87.2%, p < 0.001) for HCC diagnosis with high specificity (100% vs. 94.6%, p = 0.500).

CONCLUSION

Using the time difference method could identify HCC nodules misdiagnosed as LR-M and improve the diagnostic performance of current CEUS LI-RADS.

The diagnostic value of contrast-enhanced ultrasound LI-RADS for hepatocellular carcinoma in patients with cirrhosis and chronic hepatitis B

PURPOSE

To explore the diagnostic value of American College of Radiology Contrast-Enhanced Ultrasound-Liver Imaging Reporting and Data System (ACR-CEUS-LI-RADS) for hepatocellular carcinoma (HCC) in patients with cirrhosis and chronic hepatitis B.

METHODS

A total of 205 patients at high risk of HCC with solitary hepatic nodule were enrolled and retrospectively analyzed. All patients were over 18 years old and had a single lesion with a diameter < 50 mm. Lesions were categorized according to size and contrast enhancement patterns in the arterial, portal venous and late phases. Diagnostic efficacy of CEUS LI-RADS for HCC, and the rate of non-HCC malignancies in the LR-M class were compared between patients with cirrhosis and chronic hepatitis B.

RESULTS

Of all 205 nodules (median nodule size was 34 mm), 142 (69.3%) were HCC. Of the 127 (61.9%) LR-5 category nodules, 95.8% (92/96) nodules were corresponded to HCC in cirrhosis, while 61.3% (19/31) nodules were corresponded to HCC in chronic hepatitis B (P = 0.000). Positive predictive value (PPV) of LR-5 category for HCC was 95.8% in cirrhosis and 61.3% in chronic hepatitis B (P = 0.000). More category of LR-4 nodules were proved to be HCC in patients with cirrhosis than chronic hepatitis B (80.0% vs 8.3%, P = 0.000). Of 41 LR-M category nodules, more non-HCC malignancies were found in chronic hepatitis B (76.0%) than that in cirrhosis (25.0%, P = 0.001).

CONCLUSIONS

The LR-5 category is highly specific for the diagnosis of HCC in patients with cirrhosis. However, LR-5 category nodules require further CT or MRI examination or histological confirmation in patients with chronic hepatitis B for its unsatisfactory PPV for HCC.

Evaluation of Hepatocellular Carcinoma Patients: Interim Analysis of Cases from a Tertiary Referral Center in Craiova, Romania

Although medicine is constantly evolving, hepatocellular carcinoma remains a pathology with a poor prognosis due to the frequent delayed diagnosis and the aggressiveness of the disease.

AIM

Our objective was to evaluate liver function and stage of disease of newly diagnosed HCC patients.

METHODS

We conducted a retrospective study between July 2016 and January 2021 and we included hospitalized patients within the Department of Gastroenterology of the Emergency County Hospital of Craiova. We identified 119 newly diagnosed patients and we collected data from patient history, contrast-enhanced imaging and laboratory analysis.

RESULTS

81 patients were diagnosed in BCLC Stage A and B. Liver function was not significantly modified, despite 91.5% of the patients presented with elevated AST levels. Because of the cirrhotic liver already affected, 73 patients had thrombocytopenia. Contrast-enhanced ultrasound was performed in 79 patients, as a complementary imaging exploration. Alfa-fetoprotein values could not be correlated with the severity of disease.

CONCLUSIONS

Early diagnosis was mostly established. It is mandatory for treatment management and overall survival to follow a rigorous surveillance of patients at risk for HCC.

Ultrasonography in pediatric Budd-Chiari syndrome

Budd-Chiari syndrome is a vascular pathology of the liver, commonly seen in adults and uncommon in children. Most children with Budd-Chiari syndrome present with ascites, and an etiology is found in only about 50%. Ultrasonography (US) with color Doppler is the main modality used in the diagnosis. US imaging additionally guides radiologic interventions and follow-up after recanalization or shunt procedure. In this pictorial review, we illustrate the findings in pediatric Budd-Chiari syndrome as seen on B-mode and color Doppler US and describe the role of US in guiding percutaneous radiologic interventions, with a brief description of the role of US contrast agent and sonoelastography in this setting.

Emerging Role of Hepatobiliary Magnetic Resonance Contrast Media and Contrast-Enhanced Ultrasound for Noninvasive Diagnosis of Hepatocellular Carcinoma: Emphasis on Recent Updates in Major Guidelines

Hepatocellular carcinoma (HCC) can be noninvasively diagnosed on the basis of its characteristic imaging findings of arterial phase enhancement and portal/delayed “washout” on computed tomography (CT) and magnetic resonance imaging (MRI) in cirrhotic patients. However, different specific diagnostic criteria have been proposed by several countries and major academic societies. In 2018, major guideline updates were proposed by the Association for the Study of Liver Diseases, European Association for the Study of the Liver (EASL), Korean Liver Cancer Association and National Cancer Center (KLCA-NCC) of Korea. In addition to dynamic CT and MRI using extracellular contrast media, these new guidelines now include magnetic resonance imaging (MRI) using hepatobiliary contrast media as the first-line diagnostic test, while the KLCA-NCC and EASL guidelines also include contrast-enhanced ultrasound (CEUS) as the second-line diagnostic test. Therefore, hepatobiliary MR contrast media and CEUS will be increasingly used for the noninvasive diagnosis and staging of HCC. In this review, we discuss the emerging role of hepatobiliary phase MRI and CEUS for the diagnosis of HCC and also review the changes in the HCC diagnostic criteria in major guidelines, including the KLCA-NCC practice guidelines version 2018. In addition, we aimed to pay particular attention to some remaining issues in the noninvasive diagnosis of HCC.

Evaluation of Contrast-enhanced US LI-RADS version 2017: Application on 2020 Liver Nodules in Patients with Hepatitis B Infection

Background Use of contrast material-enhanced (CE) US Liver Imaging Reporting and Data System (LI-RADS) version 2017 has not been validated in large populations where hepatitis B virus (HBV) is endemic. Purpose To evaluate the diagnostic performance of CE US LI-RADS version 2017 in a population with a high prevalence of HBV infection. Materials and Methods In this retrospective study, liver nodules in patients with HBV who were evaluated from January 2004 to December 2016 were categorized as CE US LR-1 to LR-5 through LR-M. A subgroup of LR-M nodules was reclassified as LR-5, and additional analysis was performed. The reference standard consisted of histologic evaluation or composite imaging and clinical follow-up findings. Diagnostic performance was assessed with sensitivity, specificity, positive predictive value (PPV), and negative predictive value. Results A total of 2020 nodules in 1826 patients (median age, 54 years ± 12 [standard deviation]; 1642 men) were included. Of the 1159 LR-5 lesions, 1141 were hepatocellular carcinoma (HCC); three, intrahepatic cholangiocarcinomas; six, other malignancies; six, atypical hyperplasia; and three, benign lesions. The PPV of LR-5 for HCC was 98% (95% confidence interval [CI]: 98%, 99%). In LR-M nodules, 153 showed arterial phase hyperenhancement, early washout, and absence of punched-out appearance within 5 minutes, and 142 of 153 (93%; 95% CI: 89%, 97%) were HCC. If these nodules were reclassified as LR-5, LR-M specificity and PPV as a predictor of non-HCC malignancy increased from 88% (95% CI: 87%, 89%) and 36% (95% CI: 31%, 41%) to 96% (95% CI: 95%, 97%) and 58% (95% CI: 51%, 65%), respectively (P < .001). Despite reclassification, LR-5 specificity and PPV remained high (94% [95% CI: 92%, 96%] and 98% [95% CI: 97%, 99%], respectively). Conclusion The contrast-enhanced US Liver Imaging Reporting and Data System version 2017 category LR-5 is effectively predictive of the presence of hepatocellular carcinoma. In patients with hepatitis B virus infection, performance may be further improved by reclassification of category LR-M nodules with arterial phase hyperenhancement, early washout, and no punched-out appearance to LR-5. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Sidhu in this issue.

Clinical value of contrast-enhanced ultrasound in radiofrequency ablation for primary hepatocellular carcinoma undetectable by conventional ultrasound

BACKGROUND

Surgical resection is the first choice for the treatment of hepatocellular carcinoma (HCC). For patients who have unresectable HCC, radiofrequency ablation (RFA) is an important choice. RFA is usually guided by imaging methods including ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). CT has radiation damage, and MRI is not suitable for some patients (such as those who have pacemaker implantation, vascular stent implantation, or heart valve replacement). Ultrasound as a guidance method has the advantages of non-radiation, simplicity, and flexibility, and has been widely used in clinical practice. It has become an ideal and effective imaging method guiding RFA for liver tumors.

AIM

To investigate the clinical value of contrast-enhanced ultrasound (CEUS) in RFA for HCC undetectable by conventional ultrasound.

METHODS

A total of 52 patients with HCC undetectable by conventional ultrasound, but detected by contrast-enhanced MRI (CEMRI) and confirmed by pathology were selected as subjects (with a total of 75 tumors). All patients underwent CEUS and RFA guided by CEUS. CEMRI and CEUS were performed to evaluate the therapeutic effect after operation.

RESULTS

There was no significant difference in the detection rate between CEUS and CEMRI (P > 0.05). Time to starting enhancement and time to enhancement peak were significantly shorter in HCC tissues than in adjacent normal tissues, but peak intensity was significantly higher in HCC tissues than in adjacent normal tissues before operation (P < 0.05). Regardless of whether HCC was completely ablated or not, there was no significant difference in the accuracy rate between CEUS and CEMRI (P > 0.05). Serum alpha fetoprotein after operation was significantly lower than that before operation (P < 0.05).

CONCLUSION

CEUS can effectively detect and accurately locate HCC undetectable by conventional ultrasound and guide RFA, thus providing a reliable imaging method for evaluating RFA efficacy.

Real-Color Volume Models Made from Real-Color Sectioned Images of Visible Korean

BACKGROUND

Volume models made from magnetic resonance images on computed tomographs can produce horizontal, coronal, sagittal, and oblique planes that are used widely in clinics, although detailed structures cannot be identified. Existing real color volume models are mostly commercial and their production methods have not been released. The aim of this study was to distribute free of charge, real-color volume models produced from sectioned images with the production method.

METHODS

The original voxel size of sectioned images was increased appropriately so that the volume model could be handled by typical personal computers. By using Dicom Browser and MRIcroGL, the sectioned images were processed to become the volume models.

RESULTS

On the MRIcroGL, the resultant volume model with the voxel size of 0.5 × 0.5 × 0.5 mm³ could be displayed and freely rotated. By adjusting variables of the software, desired oblique planes could be produced instantly. With overlay function, a model of segmented structure can be overlapped to the entire volume models. The sectioned images with high quality and the segmentation data of Visible Korean enabled the identification of detailed anatomical structures on the planes.

CONCLUSION

The volume models can be used by medical students and doctors for learning sectional anatomy. Other researchers can utilize the method of this study to produce volume models from their own sectioned images.

Contrast ultrasound LI-RADS LR-5 identifies hepatocellular carcinoma in cirrhosis in a multicenter restropective study of 1,006 nodules

BACKGROUND & AIMS

The use of contrast enhanced ultrasound (CEUS) for the diagnosis of hepatocellular carcinoma (HCC) in cirrhosis was questioned because of the risk of a false positive diagnosis in cases of cholangiocarcinoma. The American College of Radiology has recently released a scheme (CEUS Liver Imaging Reporting and Data System [LI-RADS®]) to classify lesions at risk of HCC investigated by CEUS. The aim of the present study was to validate this LI-RADS scheme for the diagnosis of HCC.

METHODS

A total of 1,006 nodules from 848 patients with chronic liver disease at risk of HCC were collected in five Italian centers and retrospectively analyzed. Nodules were classified as LR-5, (HCC) if ≥1 cm with arterial phase hyperenhancement, and late washout (onset ≥60 s after contrast injection) of mild degree. Rim enhancement and/or early and/or marked washout qualified lesions as LR-M (malignant, but not specific for HCC). Other combinations qualified lesions at intermediate risk for HCC (LR-3) or probable HCC (LR-4). Diagnostic reference standard was CT/MRI diagnosis of HCC (n = 506) or histology (n = 500).

RESULTS

The median nodule size was 2 cm. Of 1,006 nodules, 820 (81%) were HCC, 40 (4%) were cholangiocarcinoma, 116 (11%) regenerative nodules (±dysplastic). The LR-5 category (52% of all nodules) was 98.5% predictive of HCC, with no risk of misdiagnosis for pure cholangiocarcinoma. Sensitivity for HCC was 62%. All LR-M nodules were malignant and the majority of non-hepatocellular origin. Over 75% of cholangiocarcinomas were LR-M. The LR-3 category included 203 lesions (HCC 96 [47%]) and the LR-4 202 (HCC 173 [87%]).

CONCLUSIONS

The CEUS LI-RADS class LR-5 is highly specific for HCC, enabling its use for a confident non-invasive diagnosis.

LAY SUMMARY

This is a retrospective study of approximately 1,000 focal lesions at risk for hepatocellular carcinoma (HCC). Herein, we demonstrate that the refined definition of the typical contrast enhanced ultrasound pattern of HCC introduced by the Liver Imaging Reporting and Data System (LI-RADS®) practically abolishes the risk of misdiagnosis of other malignant entities (e.g. cholangiocarcinoma) for HCC with negligible reduction in sensitivity. These data support the use of contrast enhanced ultrasound to diagnose HCC in cirrhosis.

Comparison of Contrast Enhanced Ultrasound With Contrast Enhanced Computed Tomography for the Diagnosis of Hepatocellular Carcinoma

BACKGROUND/AIMS

The most common primary malignant tumor of liver is hepatocellular carcinoma (HCC). The highest risk of developing HCC is seen in patients of cirrhosis. Ultrasound is used for surveillance in these patients. This study evaluates the role of contrast enhanced ultrasound (CEUS) in the diagnosis of HCC and compares CEUS to contrast enhanced computed tomography (CECT).

MATERIALS AND METHODS

This prospective study included 22 patients with cirrhosis and suspected to have HCC on the basis of gray scale ultrasound or elevated Alpha-fetoprotein. Multiphasic CECT and CEUS were done. On both CECT and CEUS, arterial phase enhancement patterns of the lesions were classified as heterogeneously hyperenhancing, homogeneously hyperenhancing, isoenhancing or nonenhancing. The enhancement patterns of the lesions in portal venous phase were classified as hyperenhancing, isoenhancing, washout or nonenhancing. Presence or absence of neovascularity and peripheral capsule were also noted. The diagnosis of HCC was made as per American Association for the Study of Liver Diseases (AASLD) guidelines.

RESULTS

There was moderate degree of agreement between the two modalities in characterizing the enhancement pattern in arterial phase, as calculated by using kappa test (k = 0.59, P < 0.05). Substantial agreement between them, for demonstrating the neovascularity, was also seen (k = 0.772, P < 0.05). CEUS was found to be superior to CECT in demonstrating portal venous phase wash out and peripheral capsule. Only fair agreement was seen between them, with kappa value for portal venous washout being k = 0.38 (P < 0.05) and for peripheral capsule being k = 0.328 (P < 0.05).

CONCLUSION

CEUS is comparable to CECT in demonstrating the arterial phase enhancement pattern of HCC and the neovascularity. CEUS was found to be better than CECT in demonstrating the portal venous phase washout and peripheral capsule.

Impact of Modified Anisotropic Diffusion-based Enhancement Method in Computer-Aided Classification of Focal Liver Lesions

This work is presented with the objective to assess quantitatively the impact of modified anisotropic diffusion-based enhancement method of Mittal et al. in computer-aided classification of focal liver lesions. This assessment was made before and after enhancement of clinically acquired ultrasound images with the comparison of (a) discrimination capability of radiologically important texture contrast feature using box plot and p-value statistics and (b) test results of designed computer-aided classification schemes to detect/classify focal liver tissues using receiver operating characteristic curves. The results reveal that the application of enhancement method on clinically acquired ultrasound image may effectively improve the confidence of clinicians/radiologists in computer-aided diagnostic solutions to detect and classify focal liver lesions.

The Practice of Using Contrast Sonography for the Differential Diagnosis of Liver Neoplasms

Purpose: to improve the differential diagnosis of benign liver rumors and the liver metastasis of colorectal cancer with the ultrasound using contrast sonography.

Materials and methods.There were evaluated 92 patients with liver neoplasms (44 (47.8%) women and 48 (52.2%) men) age 41 to 83, with a mean age of 62.8 ± 2.64. Ultrasound exam was carried out in three stages: I stage – liver ultrasound in B-mode, II stage – ultrasound in B-mode with addition of color Doppler imaging and power Doppler scanning, III stage – contrast liver sonography employing the contrast agent SonoVue (Bracco Imaging SpA, Milan, Italy). According to the results of the examination the patients were either surgically treated if there were indications, or the nature of the neoplasm was verified via the needle biopsy. Thus the patients formed two groups: I group (n = 35 (38.0%) – patients with benign liver neoplasms: cavernous hemangiomas – 17, hepatocellular adenomas – 3, focal modular hyperplasia of the liver – 5; II group (n = 57 (62.0%) – patients with metastasis of colorectal cancer.

Results.With the use of the ultrasound in B-mode with addition of color Doppler imaging and power Doppler scanning in patients from group I (n = 35) with benign tumors of the liver – bilobar involvement in 2 cases, right lobe involvement in 28 cases, left lobe involvement in 5 cases. There were found both solitary (in 33 cases) and multiple (in 2 cases) neoplasms ranging from 2.5– 4.5 cm to conglomerates of 8–17 cm in diameter. In group II (n = 57), in patients with colorectal cancer metastasis who had an ultrasound examination in B-mode with addition of color Doppler imaging and power Doppler scanning, bilobar metastatic (91.2%) involvement of the liver prevailed over the monolobar, notably right lobe (84.21%) involvement was more frequent. Multiple metastasis were encountered more often (89.5%) then solitary. At the moment of metastatic liver disease discovery the size of the tumor nodules was over 5 cm in diameter in 33 (57.8%) patients. According to the results of contrast sonography in patients of group I (n = 35) with benign tumors of the liver, there was detected a prolonged enhancement of the neoplasm in the arterial, portal and delayed phases of enhancement. In patients of group II (n = 57) with metastasis of colorectal cancer to the liver, in the end of arterial phase there was noted a “washing out” of the contrast agent by 16th second – in 36 (63.1%) of the patients, by 23th se cond – in 17 (29.8%) and by the 26th second – in 4 (7.0%) of the patients. In portal and delayed phase of the enhancement all of the group II patients (100%) at the site of the metastasis there were located anechogenic round foci.

Conclusions. 1. Complex 3-stage ultrasound examination (B-mode, color Doppler imaging and power Doppler scanning, contrast sonography) of the liver neoplasms allows to get a more detailed information and differentiate benign and metastatic disease of the liver; 2. During contrast sonography the benign liver tumors “keep” the contrast gent during the arterial, portal and delayed enhancement phases, but with metastasis in liver the contrast agent gets “washed out” already in the arterial phase of enhancement.

Predictive factors of contrast-enhanced ultrasonography for the response to transarterial chemoembolization in hepatocellular carcinoma

Background/Aims

The predictive role of contrast-enhanced ultrasonography (CEUS) before performing transarterial chemoembolization (TACE) has not been determined. We assessed the possible predictive factors of CEUS for the response to TACE.

Methods

Seventeen patients with 18 hepatocellular carcinoma (HCC) underwent TACE. All of the tumors were studied with CEUS before TACE using a second-generation ultrasound contrast agent (SonoVue®, Bracco, Milan, Italy). The tumor response to TACE was classified with a score between 1 and 4 according to the remaining enhancing-tumor percentage based on modified response evaluation criteria in solid tumors (mRECIST): 1, enhancing tumor <25%; 2, 25%≤enhancing tumor<50%; 3, 50%≤enhancing tumor<75%; and 4, enhancing tumor≥75%). A score of 1 was defined as a "good response" to TACE. The predictive factors for the response to TACE were evaluated during CEUS based on the maximum tumor diameter, initial arterial enhancing time, arterial enhancing duration, intensity of arterial enhancement, presence of a hypoenhanced pattern, and the feeding artery to the tumor.

Results

The median tumor size was 3.1 cm. The distribution of tumor response scores after TACE in all tumors was as follows: 1, n=11; 2, n=4; 3, n=2; and 4, n=1. Fifteen tumors showed feeding arteries. The presence of a feeding artery and the tumor size (≤5 cm) were the predictive factors for a good response (P=0.043 and P=0.047, respectively).

Conclusions

The presence of a feeding artery and a tumor size of less than 5 cm were the predictive factors for a good response of HCC to TACE on CEUS.

Contrast-enhanced ultrasonography in differential diagnosis of benign and malignant ovarian tumors

Objective

To evaluate the accuracy of contrast-enhanced ultrasonography (CEUS) in differential diagnosis of benign and malignant ovarian tumors.

Methods

The scientific literature databases PubMed, Cochrane Library and CNKI were comprehensively searched for studies relevant to the use of CEUS technique for differential diagnosis of benign and malignant ovarian cancer. Pooled summary statistics for specificity (Spe), sensitivity (Sen), positive and negative likelihood ratios (LR⁺/LR⁻), and diagnostic odds ratio (DOR) and their 95%CIs were calculated. Software for statistical analysis included STATA version 12.0 (Stata Corp, College Station, TX, USA) and Meta-Disc version 1.4 (Universidad Complutense, Madrid, Spain).

Results

Following a stringent selection process, seven high quality clinical trials were found suitable for inclusion in the present meta-analysis. The 7 studies contained a combined total of 375 ovarian cancer patients (198 malignant and 177 benign). Statistical analysis revealed that CEUS was associated with the following performance measures in differential diagnosis of ovarian tumors: pooled Sen was 0.96 (95%CI = 0.92∼0.98); the summary Spe was 0.91 (95%CI = 0.86∼0.94); the pooled LR⁺ was 10.63 (95%CI = 6.59∼17.17); the pooled LR− was 0.04 (95%CI = 0.02∼0.09); and the pooled DOR was 241.04 (95% CI = 92.61∼627.37). The area under the SROC curve was 0.98 (95% CI = 0.20∼1.00). Lastly, publication bias was not detected (t = −0.52, P = 0.626) in the meta-analysis.

Conclusions

Our results revealed the high clinical value of CEUS in differential diagnosis of benign and malignant ovarian tumors. Further, CEUS may also prove to be useful in differential diagnosis at early stages of this disease.

Clinically useful diagnostic tool of contrast enhanced ultrasonography for focal liver masses: comparison to computed tomography and magnetic resonance imaging

Background/Aims

To evaluate the diagnostic value of contrast (SonoVue®) enhancement ultrasonography (CEUS) and to compare this method with computed tomography (CT) and magnetic resonance imaging (MRI) in evaluating liver masses.

Methods

CEUS (n=50), CT (n=47), and MRI (n=43) were performed on 50 liver masses in 48 patients for baseline mass characterization. The most likely impression for each modality and the final diagnosis, based on the combined biopsy results (n=14), angiography findings (n=36), and clinical course, were determined. The diagnostic value of CEUS was compared to those of CT and MRI.

Results

The final diagnosis of the masses was hepatocellular carcinoma (n=43), hemangioma (n=3), benign adenoma (n=2), eosinophilic abscess (n=1), and liver metastasis (n=1). The overall diagnostic agreement with the final diagnosis was substantial for CEUS, CT, and MRI, with κ values of 0.621, 0.763, and 0.784, respectively. The sensitivity, specificity, and accuracy were 83.3%, 87.5%, and 84.0%, respectively, for CEUS; 95.0%, 87.5%, and 93.8%, respectively, for CT; and 94.6%, 83.3%, and 93.0%, respectively for MRI. After excluding the lesions with poor acoustic sonographic windows, the sensitivity, specificity, and accuracy for CEUS were 94.6%, 87.5%, and 93.3%, respectively, with a κ value of 0.765.

Conclusions

If an appropriate acoustic window is available, CEUS is comparable to CT and MRI for the diagnosis of liver masses.

The use of contrast-enhanced ultrasound in blunt abdominal trauma: advantages and limitations

Computed tomography (CT) is the imaging method of choice in the assessment of multiple trauma patients. However, in patients who suffered from low-energy abdominal trauma, the use of CT is controversial, since the probability of injury is low and therefore most of the studies are normal. Thus, conventional US imaging has increasingly been employed as the initial imaging modality in the work-up of minor traumatic emergency condition. More recently, the introduction of a new contrast-enhanced ultrasound (CEUS) technique, using second-generation ultrasound contrast agents, has led to a notable increase in the diagnostic accuracy of US in many organs. Therefore, in trauma patients, following assessment with conventional US imaging, a CEUS exam can be performed, to provide a more reliable assessment of solid organ injuries. CEUS has the potential to detect active bleeding from a variety of traumatic origins. Similar to CT, active extravasation is considered when there is evidence of contrast agent collection with echogenicity similar to that of an adjacent vessel. On the other hand, at least some drawbacks have to be addressed, including operator competence and reduced panoramic view. Moreover, CEUS, like conventional US imaging, cannot depict some lesions, such as diaphragmatic ruptures, bowel, and mesenteric traumatic injuries. This technique represents a non-invasive and repeatable method that can be performed at patient's bedside and is therefore extremely helpful for the follow-up of solid organs traumas managed conservatively, especially in pediatric patients and women of fertile age. Moreover, it may reduce the number of CT scans and expedite patient discharge.

The role of CEUS in the assessment of haemodynamically stable patients with blunt abdominal trauma

Computed tomography (CT) still represents the preferred imaging method in the assessment of patients presenting with multiple trauma. Nevertheless, in patients with low-energy abdominal trauma, the use of CT is debated because of the possible unnecessary radiation exposure. Accordingly, conventional ultrasound (US) imaging has been increasingly employed as the initial imaging modality in the workup of minor traumatic emergency conditions. Focused assessment with sonography for trauma is widely used to detect free intra-abdominal fluid, but its role is controversial, because the absence of free fluid does not exclude the presence of injuries to abdominal organ. Injection of an ultrasound contrast agent (UCA) may give the radiologist relevant additional information to that obtained with conventional US. Thus, in trauma patients, following early assessment with conventional US imaging, a contrast-enhanced US (CEUS) can provide a more reliable evaluation of solid organ injuries and related vascular complications, including active bleeding, pseudoaneurysms, and artero-venous fistulas. CEUS cannot replace abdominal CT, but it represents a noninvasive and repeatable imaging tool capable of providing a reliable assessment of trauma severity and expedite the patient's treatment.

Optimized contrast-enhanced ultrasonography for characterization of focal liver lesions in cirrhosis: A single-center retrospective study

BACKGROUND

Hepatocellular carcinoma (HCC) is the leading cause of death amongst cirrhotic patients. Its diagnosis and discrimination from non-HCC malignant lesions in cirrhosis includes contrast enhanced computed tomography (CECT), contrast enhanced magnetic resonance imaging (CEMRI), or, in selected cases, liver biopsy. The role of contrast-enhanced ultrasonography (CEUS) is still controversial.

AIMS

To evaluate whether, by selecting an appropriate 'time to wash-out' cut-off value, CEUS capability of discriminating between HCC and non-HCC malignancies in cirrhotic patients may be enhanced.

METHODS

We enrolled 282 cirrhotic patients who underwent CEUS at our institute, from January 2008 to January 2012, for focal liver lesions (FLLs) detected at ultrasound (US). We used liver biopsy and subsequent histological evaluation as the gold standard for correct classification of FLLs. We calculated the area under receiver operator characteristic curves for CEUS to distinguish patients with HCC from those with non-HCC malignancies. The best 'time to wash-out' cut-off values were selected.

RESULTS

HISTOLOGICAL DIAGNOSIS OF FLLS WAS AS FOLLOWS: 34 benign lesions (i.e. 25 regenerative nodules and 9 dysplastic nodules) and 248 malignant lesions (223 well-to-moderately differentiated HCCs; 7 poorly-differentiated HCCs; 5 intrahepatic colangiocellular carcinomas (ICCs); 5 primary non-Hodgkin B-cell lymphomas (NHBLs); and 8 metastatic liver tumors). A time to wash-out > 55 s identified patients with HCC with the highest level of accuracy (92.7%). Similarly, a time to wash-out ≤ 55 s correctly identified the vast majority of the non-HCC malignancies (100% sensitivity, 98.2% specificity and diagnostic accuracy of 98.3%).

CONCLUSIONS

CEUS is an accurate and safe procedure for discriminating FLLs in cirrhotic patients, especially when a cut-off time to wash-out of 55 s is chosen as a reference value.

Detailed analysis of temporal features on contrast enhanced ultrasound may help differentiate intrahepatic cholangiocarcinoma from hepatocellular carcinoma in cirrhosis

Aim

To verify if detailed analysis of temporal enhancement patterns on contrast enhanced ultrasound (CEUS) may help differentiate intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC) in cirrhosis.

Methods

Thirty three ICC and fifty HCC in cirrhosis were enrolled in this study. The contrast kinetics of ICC and HCC was analyzed and compared.

Results

Statistical analysis did not reveal significant difference between ICC and HCC in the time of contrast first appearance and arterial peak maximum time. ICC displayed much earlier washout than that of HCC (47.93±26.45 seconds vs 90.86±31.26 seconds) in the portal phase, and most ICC (87.9%) showed washout before 60 seconds than HCC (16.0%). Much more ICC (78.8%) revealed marked washout than HCC (12.0%) while most HCC (88.0%) showed mild washout or no washout in late part of the portal phase (90–120 seconds). Twenty six out of thirty three ICC (78.8%) demonstrated both early washout(<60seconds) and marked washout in late part of the portal phase, whereas, only six of fifty HCC (12.0%)showed these temporal enhancement features (p = 0.000).When both early washout and marked washout in the portal phase are taken as diagnostic criterion for ICC, the diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 78.8%,88.0%,81.3%,86.3%,and 84.3% respectively by CEUS.

Conclusions

Analysis of detailed temporal enhancement features on CEUS is helpful differentiate ICC from HCC in cirrhosis.If a nodule in cirrhotic liver displays hyper-enhancement in the arterial phase followed by early and marked washout in the portal phase, the nodule is highly suspicious of ICC rather than HCC.

Contrast-enhanced ultrasound in the preoperative, intraoperative and postoperative assessment of liver lesions

The use of contrast agents (CA) with liver ultrasound (US) has gained recently an established role for the diagnosis of various hepatic diseases due to their safety, high versatility and low costs (contrast-enhanced ultrasound: CEUS). The purpose of this review is to provide a state-of-the-art summary of the available evidence for their use in the characterization of focal liver lesions. A published work search was conducted for all preclinical and clinical studies involving CA on hepatic US imaging. CEUS increases the sensitivity for lesion detection and the specificity to differentiate between benign and malignant diseases due to the enhanced visualization of the tumor microcirculation. Results achieved seem at least equivalent to those of spiral computed tomography or magnetic resonance imaging. The association of CA with intraoperative ultrasound has changed the surgical approach in 25% of patients and guarantees complete ablations by a single session in most of them. CEUS provides detailed information about tumor vasculature, improves the preoperative characterization and therefore the therapeutic strategy, and can evaluate the intraoperative completeness of the ablation.

Contrast ultrasound in hepatocellular carcinoma at a tertiary liver center: First Indian experience

AIM: To assess the role of contrast enhanced ultrasonography in evaluation of hepatocellular carcinoma (HCC) at the first Indian tertiary liver center.

METHODS: Retrospective analysis of contrast enhanced ultrasound (CEUS) examinations over 24 mo for diagnosis, surveillance, characterization and follow up of 50 patients in the context of HCC was performed. The source and indication of referrals, change in referral rate, accuracy and usefulness of CEUS in a tertiary liver center equipped with a 64 slice dual energy computer tomography (CT) and 3 tesla magnetic resonance imaging (MRI) were studied. Sonovue (BR1, Bracco, Italy, a second generation contrast agent) was used for contrast US studies. Contrast enhanced CT/MRI or both were performed in all patients. The findings were taken as a baseline reference and correlation was done with respect to contrast US. Contrast enhanced MRI was performed using hepatocyte specific gadobenate dimeglumine (Gd-BOPTA). Iomeron (400 mg; w/v) was used for dynamic CT examinations.

RESULTS: About 20 (40%) of the examinations were referred from clinicians for characterization of a mass from previous imaging. About 15 (30%) were performed for surveillance in chronic liver disease; 5 (10%) examinations were performed for monitoring lesions after radiofrequency ablation (RFA); 3 (6%) were post trans-arterial chemo-embolization (TACE) assessments and 3 (6%) were patients with h/o iodinated contrast allergy. About 2 (4%) were performed on hemodynamically unstable patients in the intensive care with raised alpha fetoprotein and 2 (4%) patients were claustrophobic. The number of patients referred from clinicians steadily increased from 12 in the first 12 mo of the study to 38 in the last 12 mo. CEUS was able to diagnose 88% of positive cases of HCC as per reference standards. In the surveillance group, specificity was 53.3% vs 100% by CT/MRI. Post RFA and TACE specificity of lesion characterization by CEUS was 100% in single/large mass assessment, similar to CT/MRI. For non HCC lesions such as regenerative and dysplastic nodules, the specificity was 50% vs 90% by CT/MRI. The positive role of CEUS in imaging spectrum of HCC included a provisional urgent diagnosis of an incidentally detected mass. It further led to a decrease in time for further management. A confident diagnosis on CEUS was possible in cases of characterization of an indeterminate mass, in situations where the patient was unfit for CT/MRI, was allergic to iodinated contrast or had claustrophobia, etc. CEUS was also cost effective, radiation free and an easy modality for monitoring post RFA or TACE lesions.

CONCLUSION: CEUS is a valuable augmentation to the practice of ultrasonography, and an irreplaceable modality for confounding cases and interpretation of indeterminate lesions in imaging of HCC.

Patterns of appearance and risk of misdiagnosis of intrahepatic cholangiocarcinoma in cirrhosis at contrast enhanced ultrasound

AIM

Primary aim was to validate the percentage of intrahepatic cholangiocarcinomas (ICC) which have a contrast vascular pattern at contrast enhanced ultrasound (CEUS) at risk of misdiagnosis with hepatocellular carcinoma (HCC) and, secondary aim, to verify if any characteristics in the CEUS pattern helps to identify ICC.

METHODS

All ICC on cirrhosis seen in three Italian centres (Bologna, Milan and Pavia) between 2003 and 2011, in which CEUS and at least another imaging technique (CT or MRI) had been performed, were retrospectively identified. Those patients with ICC size comparable to the early HCC stage (Milan criteria, considered as small ICC) were enrolled for this study. The enhancement pattern at CEUS was analysed and compared with CT or MRI.

RESULTS

A total of 25 small ICC made this study group. CEUS was at risk of misdiagnosis of ICC for HCC in a significantly higher number of cases than in CT (performed in 24 ICC) (52% vs. 4.2%, P = 0.009) and MRI (11 ICC) (52% vs. 9.1%, P = 0.02). A different contrast pattern among all techniques was found in 6 of 10 ICC lesions submitted to the three imaging methods. In the arterial phase, ICC lacked global hyperenhacement in approximately 50% of cases at CEUS and the degree of intensity of wash-out in the late phase was marked in 24% of nodules.

CONCLUSIONS

CEUS misdiagnosed as HCC a significantly higher number of ICC lesions in cirrhotic patients than CT and MRI. However, some CEUS contrast features can help suspect ICC, especially in some cases with inconclusive CT or MRI.

Current consensus and guidelines of contrast enhanced ultrasound for the characterization of focal liver lesions

The application of ultrasound contrast agents (UCAs) is considered essential when evaluating focal liver lesions (FLLs) using ultrasonography (US). Microbubble UCAs are easy to use and robust; their use poses no risk of nephrotoxicity and requires no ionizing radiation. The unique features of contrast enhanced US (CEUS) are not only noninvasiveness but also real-time assessing of liver perfusion throughout the vascular phases. The later feature has led to dramatic improvement in the diagnostic accuracy of US for detection and characterization of FLLs as well as the guidance to therapeutic procedures and evaluation of response to treatment. This article describes the current consensus and guidelines for the use of UCAs for the FLLs that are commonly encountered in US. After a brief description of the bases of different CEUS techniques, contrast-enhancement patterns of different types of benign and malignant FLLs and other clinical applications are described and discussed on the basis of our experience and the literature data.

Imaging diagnosis-cholangiocellular adenoma: contrast-enhanced ultrasonographic findings of a benign tumor mimicking malignant neoplasia in a dog

A 9-year-old Giant Schnauzer was referred for polyuria and polydipsia. On abdominal ultrasound, a hyperechoic mass with low color Doppler signal was detected in the medial right hepatic lobe. Contrast-enhanced ultrasound (CEUS) demonstrated increased enhancement of the mass during the arterial phase, and contrast washout during portal and late phases with decreased enhancement relative to the liver. These findings were consistent with primary liver malignancy or liver metastasis. A final diagnosis of cholangiocellular adenoma was made based on histopathology. To our knowledge, this is the first description of a benign hepatic neoplasm exhibiting malignant CEUS characteristics in a dog.

Contrast-enhanced ultrasound in abdominal imaging

The administration of a contrast agent is considered an essential tool to evaluate abdominal diseases using Ultrasound. The most targeted organ is the liver, especially to characterize focal liver lesions and to assess the response to percutaneous treatment. However, the expanding abdominal indications of contrast-enhanced ultrasound make this technique an important tool in the assessment of organ perfusion including the evaluation of ischemic, traumatic, and inflammatory diseases.

[Detection and characterization of liver metastases]

Since the advent of second generation ultrasound (US) contrast agents, ultrasound has caught up with other imaging modalities for the detection and characterization of liver metastases and as a result of its high temporal and spatial resolution it can in some cases even be superior to computed tomography (CT) and magnetic resonance imaging (MRI). Many studies have demonstrated a sensitivity and specificity of over 90%. Due to its high temporal resolution contrast-enhanced US (CEUS) is capable of detecting even a very short duration of hyper-enhancement during the arterial phase. Radiation protection and lack of adverse effects on renal or thyroid function are additional arguments why CEUS should be recommended as the first imaging modality in the evaluation of hepatic metastases in cases of favorable scanning conditions.

[Contrast-enhanced sonography. Therapy control of radiofrequency ablation and transarterial chemoembolization of hepatocellular carcinoma]

Due to the imaging of dynamic perfusion, hepatocellular carcinoma can be detected with a sensitivity of >90% using contrast-enhanced sonography. The characterization of liver tumors with contrast-enhanced sonography is comparable to the diagnostic accuracy of contrast-enhanced computed tomography. The dynamic detection of microvascularization with contrast-enhanced sonography allows the differentiation between vascularized tumors and non-vascularized necrotic lesions before, during and after transarterial chemoembolization or percutaneous radiofrequency ablation. Image fusion with volume navigation can be useful in the followup control.

Comparison of imaging characteristics between hepatic benign regenerative nodules and hepatocellular carcinomas associated with Budd-Chiari syndrome by contrast enhanced ultrasound

PURPOSE

To compare different imaging characteristics between hepatic benign regenerative nodules and hepatocellular carcinomas (HCCs) associated with Budd-Chiari syndrome (BCS) by contrast enhanced ultrasound (CEUS).

MATERIALS AND METHODS

A total of 32 chronic BCS patients (mean age, 42 years; age range, 18-59 years) with hepatic nodules who underwent CEUS were retrospectively studied. All patients had no the history of viral hepatitis. There were 23 patients with benign regenerative nodules (22±9 mm; range, 8-42 mm) and 9 patients with HCCs (63±21 mm; range, 26-90 mm). Lesion characteristics, including number, size, vascularization on color Doppler flow imaging, echogenicity, peripheral hypoechoic rim, and enhancement patterns in arterial, portal, and late phases on CEUS, were analyzed.

RESULTS

There were significant differences in number and size of the lesions between two groups. No significant differences were observed in vascularity, echogenicity, and peripheral hypoechoic rim. Overall, there were significant differences in enhancement patterns in arterial, portal, and late phases between them on CEUS. Of 23 patients with benign regenerative nodules, 16 (70%) were center-to-periphery hyperenhanced and 7 patients (30%) were homogeneously hyperenhanced in arterial phase; the majority were homogeneously hyperenhanced in portal and late phases. Of 9 patients with HCCs, 8 (89%) were heterogeneously hyperenhanced in arterial phase and most of them were hypoenhanced in portal and late phases.

CONCLUSION

CEUS imaging characteristics of benign regenerative nodules radically differ from that of HCCs in BCS patients.

Comparison between nonspecific and necrosis-avid gadolinium contrast agents in vascular disrupting agent-induced necrosis of rodent tumors at 3.0T

OBJECTIVE

: To compare a commercial contrast agent (CA) Dotarem and a necrosis-avid CA (NACA) for their ability to evaluate the therapeutic necrosis with a vascular disrupting agent (VDA) on magnetic resonance imaging in rodent liver tumors to determine which could better correlate with the histopathologic outcome.

METHODS

: After the VDA treatment, 16 rats with 32 liver rhabdomyosarcomas were randomized into Dotarem and NACA groups (n = 8 per group) for both interindividual and intraindividual comparisons. T2-weighted imaging, T1-weighted imaging (T1WI), contrast-enhanced T1-weighted imaging (CE-T1WI), and diffusion-weighted imaging were performed at baseline, after VDA treatment and CA injections. The enhancing efficacy of CAs at immediate and delayed enhancement on CE-T1WI in viable tumor and necrosis was compared. Tumor necrosis ratios calculated from NACA and Dotarem were compared and correlated with gold-standard histopathology.

RESULTS

: On the immediate CE-T1WI, viable tumor was enhanced by either CA. On the delayed CE-T1WI at 30 minutes, both CAs failed to demarcate viable tumor from necrosis. At 24 hours post-NACA, the necrosis was clearly distinguished from viable tumor and thus derived necrosis ratio matched that from histopathology (P = 0.99); necrosis ratio from Dotarem was significantly lower than that from NACA and histopathology (P < 0.05, both), with a higher correlation of NACA than that of Dotarem with histopathology (r = 0.99 vs. r = 0.82).

CONCLUSIONS

: NACA better evaluated VDA-induced tumor necrosis than nonspecific CA on T1WI in tumor models of rat liver. NACA showed a closer correlation with histopathology than nonspecific CA for the delineation of true necrosis. Delayed enhancement on T1WI with nonspecific CA is not suitable for the assessment of VDA-induced tumor necrosis.

Evaluation of focal hepatic lesions with ultrasound contrast agents

Ultrasound contrast agents have gained wide acceptance for the detection and characterization of focal liver lesions. This pictorial essay reviews the growing body of evidence that supports the use of modern ultrasound contrast agents and illustrates the enhancement characteristics of commonly encountered focal liver lesions. Pathologies discussed include metastases, hepatocellular carcinomas, focal nodular hyperplasia, hepatocellular adenomas, hemangiomas, abscesses, complex cysts, and focal fatty deposition.

Translational imaging endpoints to predict treatment response to novel targeted anticancer agents

Response Evaluation Criteria in Solid Tumors (RECIST) and World Health Organization (WHO) Criteria have been traditionally used for the evaluation of therapeutic response to chemotherapeutic treatment regimens. They determine anatomic criteria for patients response to anti-cancer therapy based on morphological measurements of each target lesion. While this assessment is justified for cytotoxic (chemotherapeutic) drugs, it is now recognized that morphological imaging protocols are poorly suited to the evaluation of the efficacy of novel signal transduction inhibitors (STIs) which exhibit cytostatic rather than cytotoxic properties. New imaging technologies are now designed to evaluate, in a functional manner, modifications in tumor metabolic activity, cellularity, and vascularization before a reduction in tumor volume can be detected. Introduction of physiological imaging end-points, derived from dynamic contrast-enhanced (DCE) imaging protocols--including magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US)--allow for early assessment of disruption in tumor perfusion and permeability for targeted anti-angiogenic agents. Diffusion-weighted MRI (DWI) provides another physiological imaging end-point since tumor necrosis and cellularity are seen early in response to anti-angiogenic treatment. Changes in glucose and phospholipid turnover, based on metabolic MRI and positron emission tomography (PET), provide reliable markers for therapeutic response to novel receptor-targeting agents. Finally, novel molecular imaging techniques of protein and gene expression have been developed in animal models followed by a successful human application for gene therapy-based protocols.

Contrast-enhanced ultrasound of the spleen: an introduction and pictorial essay

A wide variety of pathologies can produce focal lesions within the spleen. These are being more frequently encountered as imaging technology improves. It is vital that radiologists are aware of these pathologies to enable accurate diagnosis. The role of ultrasound contrast in splenic disease will be discussed and illustrated with cases likely to be encountered by general and abdominal radiologists.

The elucidation of gene transferring mechanism by ultrasound-responsive unmodified and mannose-modified lipoplexes

The development of gene transfection methods enhancing the level of gene expression under simple and low-toxic condition is required for gene therapy in clinical. Our group has developed the ultrasound (US)-mediated gene transfection method using Man-PEG(2000) bubble lipoplexes, which are US-responsive and mannose-modified gene carriers, and succeeded in obtaining the enhanced gene expression in mannose receptor-expressing cells selectively by the gene transfer using Man-PEG(2000) bubble lipoplexes with US exposure in vitro and in vivo. Here, we investigated pDNA transferring mechanism followed by US exposure to unmodified and Man-PEG(2000) bubble lipoplexes, in particular, focused on US exposure timing. Following investigation of intracellular transferring characteristics, a large amount of pDNA was transferred into the cytoplasm followed by US-mediated destruction of bubble lipoplexes in the gene transfer using both bubble lipoplexes with US exposure. Moreover, the effective gene expression was obtained without TNF-α production when US was exposed until 5 min after the addition of bubble lipoplexes. These findings suggest that the gene transfer using unmodified and Man-PEG(2000) bubble lipoplexes with US exposure enables to transfer pDNA into the cytoplasm, and optimized US exposure timing is important to achieve the high level of gene expression and the low level of pro-inflammatory cytokine production.

Diagnostic accuracy of contrast-enhanced ultrasound in differentiating benign and malignant focal liver lesions: a retrospective study

PURPOSE

The purpose of this study was to assess the diagnostic accuracy of our early experience with contrast-enhanced ultrasound (CEUS) in the characterisation of focal liver lesions (FLLs) using histopathology, contrast-enhanced computed tomography (CT), magnetic resonance imaging (MRI) or other imaging follow-up as the standard of reference.

MATERIALS AND METHODS

Seventy-three patients with 82 FLLs who underwent liver CEUS from January 2006 to December 2008 were retrospectively reviewed. CEUS was performed with up to 4.8 mL of SonoVue® (Bracco, Milan, Italy) using a low mechanical index mode. The CEUS findings were compared with histopathology, or where histopathology was not available, clinical and imaging follow-up over at least 12 months was used as the standard of reference.

RESULTS

Of the 82 FLLs, 50 were malignant and 32 were benign at final diagnosis. CEUS correctly identified 43 malignant FLLs, with final diagnosis confirmed by histopathology in 13 lesions and clinico-radiological follow-up in 30 lesions. Twenty-nine lesions were correctly identified as benign on CEUS, with all these lesions confirmed on clinico-radiological follow-up. CEUS demonstrated a sensitivity of 86.0% and a specificity of 90.6% in the characterisation of liver lesions as malignant, with an overall accuracy of 87.8% (P < 0.05).

CONCLUSION

Our early experience has shown that CEUS can be accurate in differentiating malignant from benign FLLs and may become a useful first-line imaging tool where CT or MRI are not available or contra-indicated.

Antiangiogenic effects of pazopanib in xenograft hepatocellular carcinoma models: evaluation by quantitative contrast-enhanced ultrasonography

Background

Antiangiogenesis is a promising therapy for advanced hepatocellular carcinoma (HCC), but the effects are difficult to be evaluated. Pazopanib (GW786034B) is a pan-vascular endothelial growth factor receptor inhibitor, the antitumor effects or antiangiogenic effects haven't been investigated in HCC.

Methods

In vitro direct effects of pazopanib on human HCC cell lines and endothelial cells were evaluated. In vivo antitumor effects were evaluated in three xenograft nude mice models. In the subcutaneous HCCLM3 model, intratumoral blood perfusion was detected by contrast-enhanced ultrasonography (CEUS), and serial quantitative parameters were profiled from the time-intensity curves of ultrasonograms.

Results

In vitro proliferation of various HCC cell lines were not inhibited by pazopanib. Pazopanib inhibited migration and invasion and induced apoptosis significantly in two HCC cell lines, HCCLM3 and PLC/PRF/5. Proliferation, migration, and tubule formation of human umbilical vein endothelial cells were inhibited by pazopanib in a dose-dependent manner. In vivo tumor growth was significantly inhibited by pazopanib in HCCLM3, HepG2, and PLC/PRF/5 xenograft models. Various intratumoral perfusion parameters changed over time, and the signal intensity was significantly impaired in the treated tumors before the treatment efficacy on tumor size could be observed. Mean transit time of the contrast media in hotspot areas of the tumors was reversely correlated with intratumoral microvessel density.

Conclusions

Antitumor effects of pazopanib in HCC xenografts may owe to its antiangiogenic effects, and the in vivo antiangiogenic effects could be evaluated by quantitative CEUS.

Antiangiogenic effects of pazopanib in xenograft hepatocellular carcinoma models: evaluation by quantitative contrast-enhanced ultrasonography

BACKGROUND

Antiangiogenesis is a promising therapy for advanced hepatocellular carcinoma (HCC), but the effects are difficult to be evaluated. Pazopanib (GW786034B) is a pan-vascular endothelial growth factor receptor inhibitor, the antitumor effects or antiangiogenic effects haven't been investigated in HCC.

METHODS

In vitro direct effects of pazopanib on human HCC cell lines and endothelial cells were evaluated. In vivo antitumor effects were evaluated in three xenograft nude mice models. In the subcutaneous HCCLM3 model, intratumoral blood perfusion was detected by contrast-enhanced ultrasonography (CEUS), and serial quantitative parameters were profiled from the time-intensity curves of ultrasonograms.

RESULTS

In vitro proliferation of various HCC cell lines were not inhibited by pazopanib. Pazopanib inhibited migration and invasion and induced apoptosis significantly in two HCC cell lines, HCCLM3 and PLC/PRF/5. Proliferation, migration, and tubule formation of human umbilical vein endothelial cells were inhibited by pazopanib in a dose-dependent manner. In vivo tumor growth was significantly inhibited by pazopanib in HCCLM3, HepG2, and PLC/PRF/5 xenograft models. Various intratumoral perfusion parameters changed over time, and the signal intensity was significantly impaired in the treated tumors before the treatment efficacy on tumor size could be observed. Mean transit time of the contrast media in hotspot areas of the tumors was reversely correlated with intratumoral microvessel density.

CONCLUSIONS

Antitumor effects of pazopanib in HCC xenografts may owe to its antiangiogenic effects, and the in vivo antiangiogenic effects could be evaluated by quantitative CEUS.

Characterization of focal liver lesions with contrast-enhanced ultrasound

The introduction of second generation microbubble ultrasound (US) contrast agents, such as SonoVue (Bracco, Milan, Italy), has considerably improved the diagnostic yield of US imaging for the evaluation of focal hepatic lesions in recent years because of its ability to very sensitively depict tumoral vascularity. In addition, contrast-enhanced US (CEUS) has the advantage of the absence of ionizing radiation, the widespread availability, even at the bedside, and the possibility to characterize a lesion as soon as detected on conventional B-mode US, commonly used as the first technique for exploration of the liver. The present review focuses on the basic principles of the technique and the various patterns of benign and malignant hepatic lesions at CEUS, contributing to their characterization. Understanding of these enhancement features at CEUS according to the type of tumors enables to make more accurate characterization of focal liver lesions as well as give better advice to oncologists, hepatologists or other clinicians in case of suspected liver tumors.

The impact of vascular and nonvascular findings on the noninvasive diagnosis of small hepatocellular carcinoma based on the EASL and AASLD criteria

OBJECTIVES

Noninvasive criteria for the diagnosis of hepatocellular carcinoma (HCC) in cirrhosis, recommended by the European Association for the Study of Liver (EASL) in 2001 and by the American Association for the Study of Liver Diseases (AASLD) in 2005, have left a number of small liver neoplastic nodules undefined. We designed this prospective study in 2003 with the aims of assessing the diagnostic contribution of vascular contrast-enhanced techniques and investigating the possible additional contribution of superparamagnetic iron oxide magnetic resonance (SPIO-MR) in this setting.

METHODS

Between 2003 and 2005, 75 consecutive small (10-30 mm) liver nodules detected at ultrasonography in 60 patients with cirrhosis were prospectively submitted to contrast-enhanced ultrasound (CEUS), helical-computed tomography (helical-CT), and gadolinium magnetic resonance (gad-MR), each blinded to the other. A total of 68 nodules were also studied with SPIO-MR at the same time as gad-MR.

RESULTS

Using the EASL noninvasive criteria, the diagnosis of HCC was established in 44 of 55 (80%) nodules with a final diagnosis of HCC. Gad-MR was the most sensitive technique for detecting the typical vascular pattern. SPIO-MR showed a pattern consistent with HCC in 5 of 10 HCCs, not satisfying the EASL noninvasive criteria, and was negative in 17 of 18 (94.4%) nonmalignant nodules. The review of the present case series according to the AASLD criteria for the noninvasive diagnosis of HCC yielded a sensitivity rate of 81.8%.

DISCUSSION

This study shows that both EASL and AASLD noninvasive recall strategies for nodules of 10-30 mm in the cirrhotic liver, based on the vascular pattern of nodules, have a false-negative rate of approximately 20%. SPIO-MR may increase the diagnostic potential of noninvasive techniques, contributing to the diagnosis of HCC lacking a typical vascular pattern.

Toxicity of MRI and CT contrast agents

Anatomical and physiological imaging using CT and MRI are playing a critical role in patients' diagnosis, disease characterization and treatment planning. CT- and MRI-based protocols increasingly require an injection of iodinated CT and gadolinium (Gd)-based MRI contrast media. Although routinely used in clinical practice, iodinated and to a less extent Gd-based contrast media possess side effects: life-threatening contrast-induced nephropathy (CIN) is associated with CT and nephrogenic systemic fibrosis (NSF) with MRI contrast agents. CIN is defined as an acute decline in renal functions (serum creatinine increase > 0.5 mg/dl) after administration of iodinated contrast media. Patients with moderate-to-severe chronic kidney disease are considered the highest risk group for development of CIN. CIN is more common with ionic high-osmolar contrast CT media. NSF is a rare condition characterized by the formation of connective tissue in the skin and systemically in the lung, liver, heart and kidney. Patients with end stage kidney disease, acute kidney injury and stage 4-5 chronic kidney disease are at a high risk for NSF. The nonionic linear Gd-chelates are associated with the highest risk of NSF. This review summarizes the incidence, symptoms, safety profile of various CT and MRI contrast agents based on their physiochemical properties.

Detection of focal liver lesions: from the subjectivity of conventional ultrasound to the objectivity of volume ultrasound

PURPOSE

This study was undertaken to establish the reliability of automated volumetric liver scans in detecting focal liver lesions by evaluating the degree of agreement between conventional and volume ultrasound (US) examinations.

MATERIALS AND METHODS

Over a period of 3 months, we prospectively studied 100 consecutive patients (36 men and 64 women; age range 15-87 years; mean age 63 years) referred to our institute for US imaging of the liver. Volumetric acquisition of the liver was achieved with a 3D transducer (2.0-5.0 MHz) and a Logiq 9 US scanner. All patients underwent both 2- and 3D US studies performed by two expert radiologists. Volumetric acquisitions were subsequently reviewed by the second radiologist, who was blinded to the first radiologist's report. Three categories were established: 1=presence of focal liver lesions; 2=doubtful finding; 3=absence of focal liver lesions. Concordance between volume US and conventional US was calculated by using the k statistic.

RESULTS

Out of 100 patients examined, 39 were found to be affected by focal liver lesions. All volume US examinations were technically adequate, allowing exploration of all hepatic sectors, except for five cases that were marred by major respiratory motion artefacts. Conventional and volume US identified the same number of focal liver lesions, with the exception of four cases of doubtful findings at volume US. Concordance between automated volume US and conventional US of the liver was high (k=0.92).

CONCLUSIONS

The identification of focal liver lesions on automated volume US is possible, and the examination shows a high level of concordance with conventional US.

Characterization of canine focal liver lesions with contrast-enhanced ultrasound using a novel contrast agent-sonazoid

Contrast-enhanced ultrasound using Sonazoid, a novel contrast medium with a liver-specific Kupffer phase, was evaluated in canine focal liver lesions Twenty-five dogs with a liver mass were given intravenous Sonazoid, and the enhancement pattern in the arterial, portal, and parenchymal phase was characterized. An enhancement defect in the lesion in the parenchymal phase was observed in all malignant lesions, whereas only one of nine benign lesions had a filling defect. The diagnostic value of the presence of a filling defect for malignancy was statistically significant (100% sensitivity, 88.9% specificity, 94.1% positive predictive value, 100% negative predictive value), and was equal to that of hypoenhancement in the portal or delayed phase. The defect pattern (clear or irregular defect) was dependent (P < 0.05) on the types of malignancy (i.e., hepatocellular carcinoma and other types of malignancies). In the arterial phase, five of the six hepatocellular carcinomas had hypervascularity, whereas no other lesion was characterized by hypervascularity. In some dogs, additional lesions that could not be observed with conventional B-mode ultrasonography were detected in the parenchymal phase. The enhancement pattern of Sonazoid, especially in the parenchymal phase, has potential as a diagnostic tool for canine focal liver lesions.

Contrast-enhanced harmonic compound US of the spleen to increase staging accuracy in patients with Hodgkin lymphoma: a prospective study

PURPOSE

To prospectively compare contrast material-enhanced harmonic compound ultrasonography (US), computed tomography (CT), and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in detecting nodular infiltration in the spleen of patients with newly diagnosed Hodgkin lymphoma.

MATERIALS AND METHODS

After institutional review board approval and informed consent, 100 consecutive patients with Hodgkin lymphoma during pretreatment staging were prospectively investigated for possible spleen involvement by comparing harmonic compound US (integrated with intravenous infusion of microbubbles in 33 patients) with CT and FDG PET. Findings indicative of malignant nodules with the imaging procedures were regarded as lymphoma infiltration; in case of discrepancy, response to treatment was regarded as evidence of lymphoma.

RESULTS

Malignant nodules were detected with CT in 13 patients, with FDG PET in 13 patients, and with contrast-enhanced harmonic compound US in 30 patients. Coincidental findings of malignancy with all three imaging techniques occurred in 13 patients; 17 patients had only US-detectable malignant nodules, which showed disappearance or relevant decrease after chemotherapy. Overall, the spleen had nodular infiltration in 30 patients (13 for imaging finding concordance; 17 for typical contrast-enhanced harmonic compound US findings and chemotherapy-related nodule size modifications). Thus, both CT and FDG PET provided false-negative results in 17 of 30 patients compared with contrast-enhanced harmonic compound US, the results of which translated into disease upstaging in 13 patients.

CONCLUSION

Harmonic compound US with contrast enhancement for the characterization of possible nodules provides a higher sensitivity than does CT or FDG PET in the detection of splenic involvement by Hodgkin lymphoma.

[Contrast-enhanced ultrasound and liver imaging: review of the literature]

The advent of second-generation microbubble ultrasound contrast agents and the development of contrast specific ultrasound techniques improved the ability of contrast enhanced ultrasound (CEUS) in detecting and characterizing focal liver lesions, opening new prospects in liver imaging. A Medline search in June 2008 identified 72 published studies that used CEUS in focal liver lesion detection, characterization, and follow-up to monitor tumor ablation procedures and antiangiogenic treatment. The purpose of this paper, based on literature review, is to describe the technical recommendations when using CEUS for liver imaging and to define the different vascular patterns of the most relevant benign and malignant lesions. Diagnostic performance of CEUS and the important clinical indications are also presented and discussed. CEUS is increasingly accepted in clinical use for diagnostic imaging and post-interventional workup liver imaging. It may replace many computed tomography and magnetic resonance imaging examinations in the near future, according to the European Federation of Societies for Ultrasound in Medicine and Biology guidelines.