Real-time harmonic contrast material-specific US of focal liver lesions. Radiographics. 2005;25:333-349. [PMID: 15798053 DOI: 10.1148/rg.252045066]

Comparison contrast-enhanced CT with contrast-enhanced US in diagnosing combined hepatocellular-cholangiocarcinoma: a propensity score-matched study

OBJECTIVES

To develop and compare noninvasive models for differentiating between combined hepatocellular-cholangiocarcinoma (cHCC-CCA) and HCC based on serum tumor markers, contrast-enhanced ultrasound (CEUS), and computed tomography (CECT).

METHODS

From January 2010 to December 2021, patients with pathologically confirmed cHCC-CCA or HCC who underwent both preoperative CEUS and CECT were retrospectively enrolled. Propensity scores were calculated to match cHCC-CCA and HCC patients with a near-neighbor ratio of 1:2. Two predicted models, a CEUS-predominant (CEUS features plus tumor markers) and a CECT-predominant model (CECT features plus tumor markers), were constructed using logistic regression analyses. Model performance was evaluated by the area under the curve (AUC), sensitivity, specificity, and accuracy.

RESULTS

A total of 135 patients (mean age, 51.3 years ± 10.9; 122 men) with 135 tumors (45 cHCC-CCA and 90 HCC) were included. By logistic regression analysis, unclear boundary in the intratumoral nonenhanced area, partial washout on CEUS, CA 19-9 > 100 U/mL, lack of cirrhosis, incomplete tumor capsule, and nonrim arterial phase hyperenhancement (APHE) volume < 50% on CECT were independent factors for a diagnosis of cHCC-CCA. The CECT-predominant model showed almost perfect sensitivity for cHCC-CCA, unlike the CEUS-predominant model (93.3% vs. 55.6%, p < 0.001). The CEUS-predominant model showed higher diagnostic specificity than the CECT-predominant model (80.0% vs. 63.3%; p = 0.020), especially in the ≤ 5 cm subgroup (92.0% vs. 70.0%; p = 0.013).

CONCLUSIONS

The CECT-predominant model provides higher diagnostic sensitivity than the CEUS-predominant model for CHCC-CCA. Combining CECT features with serum CA 19-9 > 100 U/mL shows excellent sensitivity.

CRITICAL RELEVANCE STATEMENT

Combining lack of cirrhosis, incomplete tumor capsule, and nonrim arterial phase hyperenhancement (APHE) volume < 50% on CECT with serum CA 19-9 > 100 U/mL shows excellent sensitivity in differentiating cHCC-CCA from HCC.

KEY POINTS

1. Accurate differentiation between cHCC-CCA and HCC is essential for treatment decisions. 2. The CECT-predominant model provides higher accuracy than the CEUS-predominant model for CHCC-CCA. 3. Combining CECT features and CA 19-9 levels shows a sensitivity of 93.3% in diagnosing cHCC-CCA.

Efficacy of Multiple Modified Methods of Criteria for LR-M Liver Nodules of Different Sizes: Clinical Practice and Discussion in CEUS LI-RADS Version 2017

OBJECTIVES

To assess the diagnostic performance of the modified LR-M method of CEUS LI-RADS version 2017 with nodules of different sizes.

METHODS

This retrospective study included consecutive patients with high risk for HCC who underwent CEUS between 2019 and 2021, demonstrating an LR-M observed using CEUS LI-RADS version 2017. Four modified LR-M methods were used to evaluate nodules of different sizes. The diagnostic performances of the four modified LR-M methods were assessed in LR-M nodules of different sizes by the area under the receiver operating characteristic curve (AUC).

RESULTS

The 261 patients with LR-M observations included 166 HCCs and 95 non-HCCs. A total of 133 nodules were <30 mm and defined as group A, 78 nodules were 30-50 mm in size and defined as group B, and 50 nodules were >50 mm and defined as group C. The AUCs between criterion I, II, III, and IV were not significantly different in all LR-M nodules. The AUCs of the ROC curves between criterion I, II, III, and IV were not significantly different in group A. However, the AUC of criterion IV was significantly higher than that of criterion I and III in group B, and the AUCs of criterion I and criterion III were both not significant in group B; the AUC of criterion IV was not significant in group C.

CONCLUSIONS

The modified LR-M method could moderate the detection effectiveness in differentiating HCC from other lesions. According to tumor size, the selection of appropriate modified LR-M diagnostic criteria could effectively improve the diagnostic performance of LR-M.

The Role of Contrast-Enhanced Ultrasound Plus Color Parametric Imaging in the Differential Diagnosis of Subpleural Pulmonary Lesions

OBJECTIVES

To distinguish benign and malignant subpleural pulmonary lesions (SPLs) with contrast-enhanced ultrasound (CEUS) and color parametric imaging (CPI), and evaluate the role of CEUS plus CPI in the differential diagnosis of pathological types of SPLs.

METHODS

One hundred and thirty-six patients underwent CEUS with a Logiq E9 XD Clear ultrasonic machine equipped with a 3.5- to 5.0-MHz C5-1 transducer in our center were enrolled in our study, including 27 cases of benign lesions and 109 cases of malignant lesions. The ultrasound contrast agent used in this study was SonoVue. CEUS images and CPI of all cases were reviewed and analyzed by the resident and staff radiologist groups separately.

RESULTS

With CEUS alone, by both the two groups, the main enhancement pattern of benign SPLs was arborization (P < .001), while centripetal enhancement pattern occurred more frequently in malignant SPLs (P < .001). With CEUS plus CPI, by both the two groups, the main enhancement pattern of benign SPLs was arborization (P < .001), while those of malignant SPLs were centripetal (P < .001) and eccentric (P < .05). The diagnosis performance of CEUS plus CPI was significantly higher than that of CEUS alone in both the resident (area under the curve [AUC] = 0.857 vs 0.677, P < .001) and staff (AUC = 0.866 vs 0.681, P < .001) groups. Moreover, CPI offered remarkable inter-consistency improvements in the enhancement pattern determination between the two groups.

CONCLUSION

The CEUS enhancement patterns would provide information of blood perfusion patterns in the differential diagnosis of benign and malignant SPLs. The diagnosis performance could be significantly improved by CEUS plus CPI compared with CEUS alone.

Contrast-enhanced ultrasound features predict the prognosis of percutaneous microwave ablation of intrahepatic cholangiocarcinoma

OBJECTIVE

To evaluate the prognostic effect of pre-operative contrast-enhanced ultrasound (CEUS) features on intrahepatic cholangiocarcinoma (ICC) after percutaneous microwave ablation (MWA).

METHODS

A total of ICC 29 patients (average age 56.34 ± 9.78 years old, 33~75 years old) underwent MWA from March 2012 to December 2020, with a total of 58 lesions (0.5-8.1 cm, mean diameter, 2.68 ± 1.59 cm), and their pre-operative CEUS images and clinical data were collected and reviewed. Survival rate, local progression rate, intra- and extrahepatic metastasis rate were evaluated. Uni- and multivariate analysis were used to analyze the prognostic factors affecting the survival of ICC patients with pre-operative CEUS features.

RESULTS

The median follow-up time after MWA was 18.43 months (4.17-93.13 months). 1-, 2-, and 3-year OS rates were 64.4%, 48.1% and 48.1%; 6-, 12-, 18-, 24-, 36-, 48-, and 60-month local progress and extrahepatic metastasis rates were 0.0%, 4.0%, 17.7%, 17.7%, 17.7%, 17.7%, 17.7% and 3.4%, 21.5%, 32.7%, 45.6%, 55.2%, 55.2% and 77.6%, respectively. Uni- and multivariate analysis showed that post-operative extrahepatic metastasis was an important factor for long-term survival of ICC patients after MWA (p = 0.006, 0.01), and Rim-enhancement feature of pre-operative CEUS was identified as an independent predictor of post-operative extrahepatic metastasis and long-term survival (p = 0.02, 0.02).

CONCLUSION

Rim-enhancement feature of pre-operative CEUS is a predictor high post-operative extrahepatic metastasis and poor prognosis through distant microvascular metastasis after MWA of ICC patients.

ADVANCES IN KNOWLEDGE

This study determined the important CEUS features of ICC and analyzed their impact on the prognosis of ICC patients after MWA, providing scientific guidance for better clinical treatment in the future.

LR-M Observations on Contrast-Enhanced Ultrasound: Detection of Hepatocellular Carcinoma Using Additional Features in Comparison with Current LI-RADS Criteria

Background: Contrast-enhanced ultrasound (CEUS) LI-RADS assigns category LR-M for observations that are definitely or probably malignant but that are not specific on imaging for hepatocellular carcinoma (HCC). A high percentage of LR-M observations represent HCC. Objective: To retrospectively evaluate the utility of additional features, beyond conventional LI-RADS major features, for detecting HCC among LR-M observations on CEUS. Methods: This retrospective study included 174 patients (145 men, 29 women; mean age, 53 years) at high-risk for HCC who underwent CEUS from August 2014 to June 2016, demonstrating an LR-M observation using CEUS LI-RADS version 2017. Two radiologists independently assessed CEUS images for major features and four additional features (chaotic vessels, peripheral circular artery, clear boundary of the tumor enhancement, clear boundary of the intratumoral nonenhanced area). Diagnostic performance was assessed of four proposed criteria for the detection of HCC among LR-M observations. The impact on HCC detection of criteria based on the additional findings was further explored. Histology or composite imaging and clinical follow-up served as reference standard. Results: The 174 LR-M observations included 142 HCCs and 32 non-HCCs (20 intrahepatic cholangiocarcinomas, 5 combined hepatocellular-cholangiocarcinomas, 7 benign lesions). Interreader agreement of the additional features, expressed as kappa, ranged from 0.65 to 0.88. Two of the additional features exhibited PPV ≥95.0% for HCC: chaotic vessels (95.0%) and peripheral circular arteries (98.1%). The presence of either of these two additional features achieved sensitivity of 50.7%, specificity of 90.6%, PPV of 96.0%, and NPV of 29.3% for HCC. Three other explored criteria incorporating variations of major LI-RADS features, but not the additional features, had sensitivities of 55.6%-96.5%, specificities of 49.6%-68.8%, PPVs of 87.8%-90.6%, and NPVs of 25.0%-75.0%. Criteria using additional features recategorized 75 of 174 LR-M observations as LR-5, of which 72 were HCC. Conclusion: The presence of chaotic vessels and/or peripheral circular artery had high specificity and PPV for HCC among LR-M observations. Other explored criteria based on major features did not achieve higher specificity or PPV. Clinical Impact: Clinical adoption of the additional CEUS features could help establish the diagnosis of HCC noninvasively and avoid the need for biopsy of LR-M observations.

Current state of the art imaging approaches for colorectal liver metastasis

One of the most common cancers worldwide, colorectal cancer (CRC) has been associated with significant morbidity and mortality and therefore represents an enormous burden to the health care system. Recent advances in CRC treatments have provided patients with primary and metastatic CRC a better long-term prognosis. The presence of synchronous or metachronous metastasis has been associated, however, with worse survival. The most common site of metastatic disease is the liver. A variety of treatment modalities aimed at targeting colorectal liver metastases (CRLM) has been demonstrated to improve the prognosis of these patients. Loco-regional approaches such as surgical resection and tumor ablation (operative and percutaneous) can provide patients with a chance at long-term disease control and even cure in select populations. Patient selection is important in defining the most suitable treatment option for CRLM in order to provide the best possible survival benefit while avoiding unnecessary interventions and adverse events. Medical imaging plays a crucial role in evaluating the characteristics of CRLMs and disease resectability. Size of tumors, proximity to adjacent anatomical structures, and volume of the unaffected liver are among the most important imaging parameters to determine the suitability of patients for surgical management or other appropriate treatment approaches. We herein provide a comprehensive overview of current-state-of-the-art imaging in the management of CRLM, including staging, treatment planning, response and survival assessment, and post-treatment surveillance. Computed tomography (CT) scan and magnetic resonance imaging (MRI) are two most commonly used techniques, which can be used solely or in combination with functional imaging modalities such as positron emission tomography (PET) and diffusion weighted imaging (DWI). Providing up-to-date evidence on advantages and disadvantages of imaging modalities and tumor assessment criteria, the current review offers a practice guide to assist providers in choosing the most suitable imaging approach for patients with CRLM.

Differentiation of atypical hepatic hemangioma from liver metastases: Diagnostic performance of a novel type of color contrast enhanced ultrasound

BACKGROUND

In clinical practice, the diagnosis is sometimes difficult with contrast-enhanced ultrasound (CEUS) when the case has an atypical perfusion pattern. Color parametric imaging (CPI) is an analysis software for CEUS with better detection of temporal differences in CEUS imaging using arbitrary colors. It measures the differences in arrival time of the contrast agent in lesions so that the perfusion features of atypical hemangioma and colorectal cancer (CRC) liver metastasis can be distinguished.

AIM

To evaluate the role of a novel type of CPI of CEUS in the differential diagnosis of atypical hemangioma from liver metastases in patients with a history of CRC.

METHODS

From January 2016 to July 2018, 42 patients including 20 cases of atypical hemangioma and 22 cases of liver metastases from CRC were enrolled. These patients had a mean age of 60.5 ± 9.3 years (range: 39-75 years). All patients received ultrasound, CEUS and CPI examinations. Resident and staff radiologists independently and retrospectively reviewed CEUS and CPI images. Two sets of criteria were assigned: (1) Routine CEUS alone; and (2) CEUS and CPI. The diagnostic sensitivity, specificity, accuracy and receiver operating characteristic (ROC) curve of resident and staff radiologists were analyzed.

RESULTS

The following CPI features were significantly different between liver hemangioma and liver metastases analyzed by staff and resident radiologists: Peripheral nodular enhancement (65%-70.0% vs 4.5%-13.6%, P < 0.001, P = 0.001), mosaic/chaotic enhancement (5%-10% vs 68.2%-63.6%, P < 0.001, P < 0.001) and feeding artery (20% vs 59.1%-54.5%, P = 0.010, P = 0.021). CPI imaging offered significant improvements in detection rates compared with routine CEUS in both resident and staff groups. By resident radiologists, the specificity and accuracy of CEUS+CPI were significantly increased compared with that of CEUS (77.3% vs 45.5%, P = 0.030; 78.6% vs 50.0%, P = 0.006). In addition, the area under the curve (AUC) of CEUS+CPI was significantly higher than that of CEUS (0.803 vs 0.757, P = 0.036). By staff radiologists, accuracy was improved in CEUS+CPI (81.0% vs 54.8%, P = 0.010), whereas no significant differences in specificity and sensitivity were found (P = 0.144, P = 0.112). The AUC of CEUS+CPI was significantly higher than that of CEUS (0.890 vs 0.825, P = 0.013) by staff radiologists.

CONCLUSION

Compared with routine CEUS, CPI could provide specific information on the hemodynamic features of liver lesions and help to differentiate atypical hemangioma from liver metastases in patients with CRC, even for senior radiologists.

Poorly Differentiated Hepatocellular Carcinoma in a Low-risk Patient with an Otherwise Normal Liver

We herein report a 48-year-old healthy woman who visited our hospital to investigate a 25-mm space-occupying lesion in the liver. The tumor was irregularly shaped and exhibited heterogeneous enhancement on dynamic computed tomography (CT). Whole-body positron emission tomography-CT showed an abnormal fluorodeoxyglucose uptake in the liver tumor, with a maximum standardized uptake value of 12.82. During the ensuing three months, the tumor grew rapidly and the serum alpha-fetoprotein levels also rose; partial hepatectomy was therefore performed. Microscopic findings revealed a moderately-to-poorly differentiated hepatocellular carcinoma in the normal liver.

Additional value of contrast-enhanced ultrasonography for fusion-guided, percutaneous biopsies of focal liver lesions: prospective feasibility study

PURPOSE

To determine the value of CEUS for real-time, fusion-guided, percutaneous biopsies of focal liver lesions.

MATERIALS AND METHODS

Institutional review board approval and written informed consents were obtained for this study. Forty patients with focal liver lesions identified on CT/MRI were prospectively enrolled. For biopsy planning, real-time fusion of CT/MRI with USG (USG-Fusion) was performed, and subsequently real-time CEUS was fused with CT/MRI (CEUS-Fusion). We evaluated lesion visibility, confidence level of technical success before the procedure, and safety route accessibility on USG-Fusion and CEUS-Fusion. Occurrence of change in the biopsy target was also assessed.

RESULTS

Among 40 target lesions, nine (22.5%) lesions were invisible on USG-Fusion. After applying CEUS-Fusion, seven of nine (77.8%) lesions were visualized. Confidence level of technical success of procedure was significantly increased on CEUS-Fusion compared USG-Fusion (p = 0.02), and presumed target lesions were changed in 16 (40%) patients after CEUS-Fusion. As the lesion is necrotic, presumed target was more frequently changed after CEUS-Fusion (50.0% and 25.0%). Confirmative diagnostic results were reported in 39 (97.5%) patients. Accessibility of the safety route to target lesions did not reach statistical differences.

CONCLUSION

Applying a new, real-time CEUS-Fusion with CT/MRI improved tumor visibility and viable portion assessment, thus leading to higher operator confidence and diagnostic yield, when compared with conventional USG-Fusion.

Differentiation of intrahepatic cholangiocarcinoma from hepatocellular carcinoma in high-risk patients: A predictive model using contrast-enhanced ultrasound

AIM

To develop a contrast-enhanced ultrasound (CEUS) predictive model for distinguishing intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC) in high-risk patients.

METHODS

This retrospective study consisted of 88 consecutive high-risk patients with ICC and 88 high-risk patients with HCC selected by propensity score matching between May 2004 and July 2016. Patients were assigned to two groups, namely, a training set and validation set, at a 1:1 ratio. A CEUS score for diagnosing ICC was generated based on significant CEUS features. Then, a nomogram based on the CEUS score was developed, integrating the clinical data. The performance of the nomogram was then validated and compared with that of the LR-M of the CEUS Liver Imaging Reporting and Data System (LI-RADS).

RESULTS

The most useful CEUS features for ICC were as follows: rim enhancement (64.5%), early washout (91.9%), intratumoral vein (58.1%), obscure boundary of intratumoral non-enhanced area (64.5%), and marked washout (61.3%, all P < 0.05). In the validation set, the area under the curve (AUC) of the CEUS score (AUC = 0.953) for differentiation between ICC and HCC was improved compared to the LI-RADS (AUC = 0.742) (P < 0.001). When clinical data were added, the CEUS score nomogram was superior to the LI-RADS nomogram (AUC: 0.973 vs 0.916, P = 0.036, Net Reclassification Improvement: 0.077, Integrated Discrimination Index: 0.152). Subgroup analysis demonstrated that the CEUS score model was notably improved compared to the LI-RADS in tumors smaller than 5.0 cm (P < 0.05) but not improved in tumors smaller than 3.0 cm (P > 0.05).

CONCLUSION

The CEUS predictive model for differentiation between ICC and HCC in high-risk patients had improved discrimination and clinical usefulness compared to the CEUS LI-RADS.

The usefulness of contrast-enhanced harmonic EUS-guided fine-needle aspiration for evaluation of hepatic lesions (with video)

BACKGROUND AND AIMS

Small hepatic masses often do not have distinct margins on B-mode EUS images. Contrast-enhanced harmonic EUS (CEH-EUS) is widely used for evaluating ambiguous pancreatic lesions. However, its role in detecting hepatic lesions and the use of EUS-guided FNA are not well evaluated. We investigated the usefulness of CEH-EUS-guided FNA for evaluating hepatic lesions.

METHODS

Thirty consecutive patients with hepatic masses underwent CEH-EUS and CEH-EUS-guided FNA between September 2010 and November 2016.

RESULTS

Twenty-eight patients (93.3%) had malignant tumors and 2 patients (6.7%) had benign hepatic masses. Before contrast enhancement, 73.3% of the hepatic lesions (22/30) in the patient cohort were visible on B mode. After contrast enhancement, 93.3% of these hepatic lesions (28/30) were distinguishable from the surrounding liver parenchyma. The technical success rate was 100%. The median tumor size on EUS and the number of needle passes were 24.5 mm (interquartile range [IQR], 14.5-40.8) and 2 (IQR, 2-3), respectively. The diagnostic accuracy of CEH-EUS-guided FNA was 86.7% (26/30 cases). There were no procedure-related adverse events.

CONCLUSIONS

CEH-EUS-guided FNA can be a safe and efficient method for the diagnosis of hepatic masses. It can result in high diagnostic accuracy in cases where the hepatic lesions are poorly visible on conventional EUS.

3D image guidance assisted identification of colorectal cancer liver metastases not seen on intraoperative ultrasound: results from a prospective trial

BACKGROUND

Neoadjuvant treatment of colorectal liver metastases has become increasingly common, and while effective, often renders small metastases difficult to visualize on intraoperative US. The objective of this study was to determine the utility of a 3D image-guidance system in patients with intraoperative sonographically-occult CRLM.

METHODS

50 patients with at least one CRLM ≤ 1.5 cm were enrolled in this prospective trial of an FDA-approved Explorer image-guidance system. If the tumor(s) seen on preoperative imaging were not identified with intraoperative US, Explorer was used to target the US examination to the involved area for a more focused assessment. The primary endpoint was the proportion of cases with sonographically-occult metastases identified using Explorer.

RESULTS

Forty-eight patients with preoperative scans within eight weeks of surgery were included for analysis. Forty-six patients were treated with preoperative chemotherapy (median 4 months, range 2-24 months). Overall, 22 sonographically-occult tumors in 14 patients were interrogated by Explorer, of which 15 tumors in 10 patients were located with image-guidance assistance. The only difference between patients with tumors not identified on US and those who did was the number of tumors (median 3 vs. 2, p = 0.018).

CONCLUSION

3D image-guidance can assist in identifying small CRLM, particularly after treatment with chemotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02806037, https://clinicaltrials.gov/ct2/show/NCT02806037.

Contrast enhanced ultrasound guided biopsies of liver lesions not visualized on standard B-mode ultrasound-preliminary experience

Background

To assess the technical success of contrast enhanced ultrasound (CEUS) guided biopsies of liver lesions poorly visualized on B-mode ultrasound.

Methods

Patients were selected during the procedure based on the real-time clinical scenario of unsatisfactory B-mode ultrasound lesion visualization and all patients would have otherwise undergone CT guided liver lesion biopsy. A total of 26 patients underwent CEUS guided biopsy and were included in this retrospective analysis. The review of the patients' files included demographic information, lesion characteristics on imaging, procedural details and pathology outcome. Technical success was defined as concordance between the radiological findings, pathology report and clinical follow-up-demonstrating lack of need for re-biopsy or re-biopsy with identical pathological results. Patients with less than 2 months follow-up were excluded from the study.

Results

CEUS guided liver biopsy was successful in 23 out of 26 patients (88.5%). The average procedure time was 30.7±12.3 minutes and the average lesion size was 2.2±1.7 cm. The majority of lesions (80.8%) were hypoenhancing on the delayed phase of CEUS. The mean number of samples taken from each lesion per procedure was 3.2 (±1.7).

Conclusions

CEUS guidance biopsies of focal liver lesions (FLL) that were difficult to visualize on B-mode ultrasound demonstrated high success rate and may be an evolving image guidance modality in selected patients to avoid CT guided procedures.

Diagnostic Performance and Confidence of Contrast-Enhanced Ultrasound in the Differential Diagnosis of Cystic and Cysticlike Liver Lesions

OBJECTIVE

The aims of this study were to assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) in the characterization of atypical cystic and cysticlike focal liver lesions in comparison with conventional US and to determine whether the use of CEUS can reduce the need for further diagnostic workup.

SUBJECTS AND METHODS

In a 3-year period 48 patients with 50 atypical cystic and cysticlike lesions found at conventional US underwent CEUS. Diagnostic confirmation was obtained in cytohistopathologic examinations, with other imaging modalities, and in follow-up. Overall, there were 24 cystic lesions and 26 cysticlike solid lesions, specifically 32 benign and 18 malignant lesions. The conventional US and CEUS images and cine loops were reviewed by two blinded readers independently. Sensitivity, specificity, area under the ROC curve (A_z), and interobserver agreement were calculated.

RESULTS

Diagnostic performance improved after review of CEUS examinations by both readers (conventional US A_z = 0.781 vs 0.972; CEUS A_z = 0.734 vs 0.957). Interreader agreement increased, although slightly (conventional US weighted κ = 0.894; CEUS weighted κ = 0.953). In terms of differential diagnosis, the occurrence of correctly characterized lesions increased after CEUS for both readers (reader 1, 62% to 98%; reader 2, 56% to 96%).

CONCLUSION

The development of low-acoustic-power CEUS has made it possible to identify several imaging features of cystic and cysticlike focal liver lesions that, in association with history and clinical findings, may help to correctly characterize them. Our data indicate the usefulness of CEUS in the evaluation of patients with these lesions.

Predictive factors of long-term colorectal cancer survival after ultrasound-controlled ablation of hepatic metastases

BACKGROUND AND OBJECTIVE

The risk factors associated to long-term survival were assessed in patients with liver metastases of colorectal carcinoma undergoing ablative therapies.

PATIENTS AND METHODS

Single-centre cohort study, retrospectively analysed and prospectively collected consecutive patients with unresectable metastatic liver disease of colorectal carcinoma treated with ablative therapies between 1996 and 2013. Factors associated with survival time were identified using Cox's proportional hazard model with time-dependent covariates. A forward variable selection based on Akaike information criterion was performed. Relative risk and 95% confidence intervals for each factor were calculated. Statistical significance was set as P<.05.

RESULTS

Seventy-five patients with liver metastases of colorectal cancer, with a mean age of 65.6 (10.3) underwent 106 treatments. Variables selected were good quality of life (RR 0.308, 95% CI 0.150-0.632) and tumour extension (RR 3.070, 95% CI 1.776-5.308). The median overall survival was 18.5 months (95% CI 17.4-24.4). The survival prognosis in median was 13.5 vs. 23.4 months for patients with and without tumour extension, and 23.0 vs. 12.8 months for patients with good and fair or poor quality of life, respectively.

CONCLUSIONS

Good quality of life and tumour extension were the only statistically significant predictors of long-term survival in patients of colorectal carcinoma with liver metastatic disease undergoing ablative treatment with ultrasound.

Contrast-Enhanced Ultrasound in the Assessment of Patients with Indeterminate Abdominal Findings at Positron Emission Tomography Imaging

Widespread use of fluorodeoxyglucose-positron emission tomography (PET) in cancer imaging may result in a number of indeterminate and false-positive findings. We investigated the role of contrast-enhanced ultrasound (CEUS) as a second-level option after inconclusive PET. We reviewed CEUS images acquired over 4 y, selecting the examinations performed specifically to better assess an unclear PET image. Final diagnosis was confirmed by biopsy, surgery, further imaging or follow-up. Seventy CEUS examinations were performed after a PET scan (44 PET examinations, 19 PET-computer tomography [CT] examinations and 7 PET-CECT examinations). The target organ was the liver in 54 cases, spleen in 12, gallbladder in 2 and pancreas and kidney in one each. In 6 of 70 cases, CEUS was performed because of a negative PET (no uptake) despite an abnormal finding on the CT images of the PET-CT study; CEUS allowed a correct diagnosis in all of these. In 20 of 70 cases, the PET findings were categorized as indeterminate and non-specific (non-specific fluorodeoxyglucose uptake in PET report with no standardized uptake value given); CEUS reached a correct diagnosis in 19 of the 20 cases with one false negative. In 34 of 70 cases, PET was indeterminate, but specific (fluorodeoxyglucose uptake with a standardized uptake value provided); CEUS reached a correct diagnosis in 30 of these 34 cases. In 10 of 70 cases, PET was categorized as determinate but to be investigated because of discrepancy with clinical or imaging findings; CEUS a definitive diagnosis in 9 of 10 cases. CEUS proved to be effective option in the assessment of cancer patients with indeterminate PET findings.

Focal Lesions in Fatty Liver: If Quantitative Analysis Facilitates the Differentiation of Atypical Benign from Malignant Lesions

To evaluate the diagnostic performance of quantitative analysis as an adjunctive diagnostic tool to contrast-enhanced ultrasound (US) for the differentiation of atypical benign focal liver lesions (FLLs) from malignancies in fatty liver. Twenty-seven benign FLLs and fifty-six malignant FLLs that appeared hyper-enhanced during the arterial phase with washout in the portal or late phase in fatty liver were analyzed. Chi-square tests and logistic regression were applied to identify the specific features. Three sets of criteria were assigned: 1) all FLLs subjected to routine contrast-enhanced US; 2) all FLLs subjected to quantification analysis and contrast-enhanced US; and 3) parts of FLLs that could not be diagnosed using contrast-enhanced US (n = 66, 75.9%) but instead were diagnosed using parametric features. The sensitivity, specificity, accuracy and area under the receiver operating characteristic curve (AUC) of the three sets of criteria were analyzed. The AUCs of the criterion set 2 were significantly higher than those of criterion set 1 (0.904 versus 0.792, P = 0.008). Criterion set 3 showed a relatively high sensitivity (90.2%) with a relatively high AUC (0.845). The quantification analysis offers improved diagnostic performance for the differential identification of atypical benign FLLs from malignancies in fatty liver.

Contrast-enhanced ultrasound in the characterization of complex cystic focal liver lesions

Complex cystic focal liver lesions (FLLs) found at non-contrast ultrasound (US) may turn out to be malignant. In this prospective, monocentric study we investigated the value of contrast-enhanced US (CEUS) in the differential diagnosis of complex cystic FLLs. In the past 3 years, all patients with complex cystic FLLs unclassifiable at US underwent CEUS with low-transmit insonation power. We evaluated 36 consecutive patients with 61 FLLs (1-6/patient, mean = 2). The diameter of the lesions ranged from 1.1 to 7.9 cm (mean = 3.9 cm). Sixteen patients had an extrahepatic malignancy. There were 42 malignant lesions and 19 benign lesions. No lesion had a certain diagnosis at conventional US, whereas 16 FLLs were classified as probable (benign or malignant) and 45 as uncertain. CEUS correctly categorized 95% of the malignant cases. CEUS was not able to differentiate the biliary cystadenoma from its malignant counterpart and misdiagnosed two abscesses. Complete non-enhancement throughout three phases or sustained enhancement in the portal/late phase was exhibited in most benign complex cystic FLLs, except for 1 (of the 3) cystadenomas and in 2 (of the 4) abscesses. On the other hand, all malignant lesions presented a contrast washout with a hypo-enhancing appearance. CEUS may provide added diagnostic value in all complex cystic FLLs found uncertain at conventional US, potentially avoiding the use of more invasive and expensive imaging modalities.

Differentiation of Atypical Hepatocellular Carcinoma from Focal Nodular Hyperplasia: Diagnostic Performance of Contrast-enhanced US and Microflow Imaging

PURPOSE

To evaluate diagnostic performance of contrast-enhanced (CE) ultrasonography (US) and microflow (MF) imaging in differentiation of atypical hepatocellular carcinoma (HCC) from focal nodular hyperplasia (FNH).

MATERIALS AND METHODS

Institutional review board approval was obtained, and informed consent was waived. A total of 103 patients (mean age, 43.9 years; age range, 17-75 years) were included; 38 patients with HCC and 65 with FNH underwent CE US, and vascular architecture pattern (VAP) and arrival time parametric (ATP) images were analyzed. Resident and staff radiologists independently and retrospectively reviewed CE US, VAP, and ATP images. χ(2) test and logistic regression analysis were applied to identify specific features of FNH or HCC on CE US and MF images. To compare diagnostic performance of CE US with or without MF imaging, four sets of criteria were assigned: (a) routine CE US alone, (b) VAP and CE US, (c) ATP imaging and CE US, and (d) all three methods in combination. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) of resident and staff radiologists were analyzed. Cohen κ statistic was used to assess agreement of CE US and MF imaging features between staff and resident radiologists.

RESULTS

MF imaging offered significant improvements over most detection rates achieved with routine CE US signs in both groups. For staff radiologists, AUCs from criteria sets 3 (AUC = 0.873, P < .05) and 4 (AUC = 0.887, P < .05) were significantly higher than AUC from criteria set 1 (AUC = 0.835). For resident radiologists, specificity (71% and 69% vs 25%, P < .01) and accuracy (78% and 79% vs 50%, P < .01) of criteria sets 3 and 4 were significantly higher than those of criteria set 1. Moreover, AUCs for criteria sets 2 (AUC = 0.728, P < .05), 3 (AUC = 0.823, P < .01), and 4 (AUC = 0.857, P < .01) were significantly higher than those for criteria set 1 (AUC = 0.667).

CONCLUSION

When compared with routine CE US, MF imaging can more effectively depict specific features and offers improved diagnostic performance in the differentiation of atypical HCC from FNH, especially when used by resident radiologists. Online supplemental material is available for this article.

Efficacy of contrast enhanced grey scale ultrasound in characterisation of hepatic focal lesions: A pilot study

BACKGROUND

Contrast enhanced ultrasound (CEUS) has recently gained widespread acceptance as an adjunct to conventional grey scale ultrasound. The present pilot study was undertaken to evaluate the efficacy of this technique in characterisation of hepatic focal lesions.

METHODS

Adult patients who had at least one focal liver lesion underwent ultrasound evaluation in regular and contrast mode before and after intravenous administration of sulphur hexafluoride. The diagnoses were confirmed by comparison with a reference standard (multidetector CT), response to treatment or pathological correlation.

RESULTS

The rate of correct diagnosis for unenhanced ultrasound was 54%, CEUS was 72% and multidetector CT (MDCT) was 92%. A comparison of unenhanced ultrasound versus CEUS using the McNemar test yielded a p value of 0.0704 (>0.05). However, comparison of CEUS versus MDCT using the McNemar test yielded a p value of 0.0265 (<0.05). Additionally, comparison of unenhanced ultrasound versus MDCT using the McNemar test yielded a p value of <0.0001.

CONCLUSION

CEUS increases diagnostic efficacy over unenhanced ultrasound but does not have any significant advantages over MDCT. Currently it may be used as a problem solving tool in atypical haemangiomas, echogenic focal liver lesions, contrast sensitivity and to avoid multiple studies utilising ionising radiation.

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.

Evaluation of the vascular architecture of focal liver lesions using micro flow imaging

OBJECTIVES

To identify the vascular architecture of focal liver lesions using micro flow imaging and compare it with characteristics on contrast harmonic imaging during the arterial phase.

METHODS

Micro flow imaging and contrast harmonic imaging were performed in 118 patients with various focal liver lesions: hepatocellular carcinoma (n = 70), metastasis(n = 19), intrahepatic cholangiocarcinoma (n = 3), lymphoma (n = 1), hemangioma (n = 17), and focal nodular hyperplasia (n = 8). The vascular architecture of the lesions on micro flow imaging was evaluated by 2 investigators independently to reveal 6 patterns (types IVI). Enhancement characteristics on contrast harmonic imaging were also evaluated.

RESULTS

Inter-reader agreement for delineating the vascular architecture was higher on contrast harmonic imaging (κ= 0.856) than micro flow imaging (κ= 0.613). On micro flow imaging, the vascular patterns of hepatocellular carcinomas were types I (28.6%), II (65.7%), and III (5.7%). On contrast harmonic imaging, 44 of 70 (62.9%) hepatocellular carcinomas showed chaotic vessels, of which 40 were type II and 4 were type II. The vascular patterns of metastases were types IV (78.9%), I (10.5%), and II (10.5%). Typical rim enhancement was identified in 57.9% of metastases on contrast harmonic imaging, and all were type IV. The vascular patterns of focal nodular hyperplasia were types VI (87.5%) and I (12.5%). Typical spoked wheel arteries were identified on contrast harmonic imaging in 2 focal nodular hyperplasia cases. The vascular patterns of hemangiomas were types V (94.1%) and II (5.9%). Typical peripheral nodular enhancement was identified in 88.2% of hemangiomas on contrast harmonic imaging, and all were type V. The χ(2) test revealed that differences in vascular architecture between the lesions were significant on micro flow imaging (P < .001).

CONCLUSIONS

Micro flow imaging permitted detailed delineation of the vascular architecture of focal liver lesions. Hepatocellular carcinoma, metastasis, focal nodular hyperplasia, and hemangioma showed characteristic vascular architecture.

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.

The varied sonographic appearances of focal fatty liver disease: review and diagnostic algorithm

Focal fat infiltration and focal fat sparing of the liver are less common than diffuse fat infiltration but present a greater diagnostic conundrum. Although typical features of these conditions are well described, there is a wide variety of different appearances. These atypical patterns present significant difficulty in differentiation from other pathological processes and often require additional investigation. We present an innovative diagnostic algorithm and illustrate its effectiveness in diagnosing focal fatty liver disease with typical and atypical examples.

Contrast-enhanced ultrasound-guided microwave ablation for hepatocellular carcinoma inconspicuous on conventional ultrasound

OBJECTIVE

To evaluate the efficiency and feasibility of contrast-enhanced ultrasound (CEUS)-guided microwave ablation for hepatocellular carcinoma inconspicuous on conventional US.

MATERIALS AND METHODS

From March 2006 to February 2010, 107 patients (93 male, 14 female; mean age 58.9±11.0 years) with 107 hepatocellular carcinoma (HCC) nodules (mean maximum diameter 19.5±8.5 mm) inconspicuous on conventional US underwent microwave (MW) ablation under CEUS guidance in this study. US contrast agent was SonoVue (Bracco, Milan, Italy), a second-generation contrast agent. CEUS was performed first, and then MW ablation was carried out by means of CEUS guidance under unconscious intravenous anaesthesia if the tumours were displayed on CEUS.

RESULTS

105 tumours were successfully visualised on CEUS by using 1-2 times contrast agent injection and MW ablation was performed under CEUS guidance. The technical success rate was 98.13% (105/107). The number of antenna insertions for each tumour was 1.89±0.92, and the mean session of MW ablation for each tumour was 1.08±0.28. The mean duration of energy application for each tumour was 7.05±4.03 min. The follow-up time was 12-54 months (median 18 months). The technique effectiveness rate was 99.05% (104/105). The local tumour progression rate was 1.9% (2/105). There were no severe complications in any patients.

CONCLUSION

CEUS-guided MW ablation is an efficient and feasible treatment method for patients with hepatocellular carcinoma inconspicuous on conventional US.

Source and clinical motivation of orders for contrast-enhanced sonography (CEUS) of the liver: A prospective single-center survey

Contrast-enhanced sonography (CEUS) has become a routine part of diagnostic imaging of the liver. Its possibilities, limitations, and indications have been defined in adequately large clinical series and in guidelines and recommendations. We prospectively evaluated physicians' orders for hepatic CEUS received in the radiology department of a large oncology center in Naples, Italy from May 2009 to April 2010. Radiologists performing the CEUS examinations filled out a form that included patient demography, source and type of patient referral, and clinical indications for the examination. During the study period, 564 patients aged 17-86 years (mean, 58 years) were referred to our department for CEUS liver studies (total: 644; 491 outpatient studies, 153 inpatient studies). This included 4 examinations that were ordered by the patient's physician but not performed by our staff. The majority of the CEUS examinations (n = 583; 90.5%) were regularly scheduled procedures ordered by clinical specialists from our center (77.3%) or other centers (11.8%); by general practitioners (on their own initiative) (0.8%); or by other figures (0.6%). The remaining 61 examinations (9.5%) were unscheduled procedures done on the initiative of a radiologist following conventional sonography (US). Fewer than half (47.8%) of the examinations were requested as first-line assessments. The others were ordered to clarify inconclusive findings generated by conventional US (30%) or by a more sophisticated imaging study (CT, MRI, PET) (16.1%) or to resolve discrepancies between CT, MRI, and/or PET findings (6%). CEUS is a relatively noninvasive, low-cost imaging study that is simple to perform and requires no particular patient preparation. This may explain its increasing use to clarify doubts raised by conventional US and other more sophisticated imaging studies.

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.

Real-time contrast-enhanced ultrasound-guided biopsy of focal hepatic lesions not localised on B-mode ultrasound

OBJECTIVE

To prospectively evaluate the technical feasibility of percutaneous real-time contrast-enhanced ultrasound (CEUS) guided biopsy of focal hepatic lesions that are not confidently localised on B-mode US.

METHODS

The study included 44 patients (mean age, 61.3 years) whose biopsy target could not be confidently localised on B-mode US performed by two independent radiologists. Biopsy was attempted under the guidance of both CEUS and B-mode US simultaneously displayed on a single monitor. Final diagnosis was established based on the pathological examination of the biopsy specimen as well as on clinical and radiological follow-up.

RESULTS

The size and depth of the target lesions were 18.0 +/- 9.0 mm (mean +/- SD) and 41.8 +/- 17.2 mm respectively. Five patients with negative or indistinct CEUS findings did not undergo biopsy, while 39 patients completed the biopsy. In 38 of the 39 patients, the biopsy result was concordant with the final diagnosis. In the remaining one patient, the biopsy failed to prove metastasis. As there were six cases of technical failure, the technical success rate was 86% (38/44). The sensitivity in diagnosing malignancy was 88% (30/34).

CONCLUSION

Real-time CEUS-guided biopsy is technically feasible for hepatic focal lesions that are not confidently localised on B-mode US.

Utility of contrast-enhanced ultrasound for evaluation of thyroid nodules

BACKGROUND

No conventional imaging method reliably distinguishes between benign and malignant thyroid nodules. Our objectives were to characterize the enhancement patterns of thyroid nodules on gray-scale contrast-enhanced ultrasound (US) and to evaluate whether these patterns were useful in the differential diagnosis of thyroid nodules.

METHODS

Ninety-five patients, scheduled for surgery for thyroid nodules detected by gray-scale sonography, were enrolled in this prospective study. In all, there were 104 nodules (47 papillary carcinomas, 3 medullary carcinomas, 1 metastatic carcinoma, 44 hyperplasia nodule, 7 follicular adenomas, 1 suture granulomas, and 1 Hashimoto's disease). After intraveneous (i.v.) injection of a 1.2 mL bolus of SonoVue, lesions were scanned with real-time gray-scale pulse inversion harmonic imaging US for at least 3 minutes at low mechanical index (MI) (0.05 to 0.08). The enhancement patterns were classified into one of four patterns by two experienced readers.

RESULTS

After administration of SonoVue, four enhancement patterns (homogeneous, heterogeneous, ring-enhancing, and no enhancement) were observed. Four benign and 3 malignant nodules had homogeneous enhancement pattern, 4 benign and 45 malignant nodules had heterogeneous enhancement, 44 benign and 3 malignant nodules had ring enhancement, and 1 benign nodule had no enhancement. There was a significant difference between benign and malignant nodules (p < 0.001). The benign thyroid nodules showed four enhancement patterns: ring enhancement 44/53 (83.0%), homogeneous enhancement 4/53 (7.5%), heterogeneous enhancement 4/53 (7.5%), and no enhancement 1/44 (1.9%). The malignant thyroid nodules showed three enhancement patterns: heterogeneous enhancement 45/51 (88.2%), ring enhancement 3/51 (5.9%), and homogeneous enhancement 3/51 (5.9%). Ring enhancement correlated highly with a benign diagnosis (sensitivity 83.0%, specificity 94.1%, positive predictive value 93.6%, negative predictive value 84.2%, and accuracy 88.5%). Heterogeneous enhancement correlated highly with a malignant diagnosis (sensitivity 88.2%, specificity, 92.5% positive predictive value 91.8%, negative predictive value 89.1%, and accuracy 90.4%). In both mixed and solid nodules, ring enhancement was highly predictive of a benign finding, whereas heterogeneous enhancement was highly predictive of a malignant finding.

CONCLUSIONS

Contrast-enhanced US enhancement patterns were different in benign and malignant lesions. Ring enhancement was predictive of benign lesions, whereas heterogeneous enhancement was helpful for detecting malignant lesions.

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 sonography of a hepatocellular carcinoma undergoing spontaneous necrosis

Spontaneous necrosis of hepatocellular carcinoma (HCC) is rare. We report the case of a 72-year-old woman with an HCC nodule that underwent necrosis after sonographically guided needle biopsy. Baseline sonographic examination revealed only a nonspecific change in the echogenicity of the lesion. Subsequent necrosis was suggested on contrast-enhanced sonographic examination and was confirmed on spiral CT.

Focal liver lesions: can SonoVue-enhanced ultrasound be used to differentiate malignant from benign lesions?

OBJECTIVE

To evaluate whether contrast-enhanced ultrasound (CEUS) with SonoVue could differentiate malignant focal liver lesions (FLLs) from benign lesions and provide lesion type diagnoses.

MATERIALS AND METHODS

Four hundred fifty-six patients with 554 FLLs were examined by CEUS with SonoVue using low mechanical index, nonlinear imaging techniques. Each lesion was characterized by 2 independent off-site readers as malignant or benign and given specific lesion type diagnosis, if possible, both at baseline ultrasound (US) and after SonoVue administration (CEUS). The final diagnosis was achieved by histopathology obtained from biopsy or surgical specimens, or by typical manifestation on contrast-enhanced CT or MRI.

RESULTS

The diagnostic accuracies of the 2 readers were 41.9% and 35.2% for baseline US, which improved significantly to 87.2% and 87.9% for CEUS (P < 0.05). Interreader agreement also increased with CEUS compared with baseline US (ê value changed from 0.49 to 0.77). The accuracy for lesion type diagnosis was 38.4% and 32.5% for baseline US, which increased to 77.6% and 78.0% for CEUS (P < 0.05).

CONCLUSIONS

CEUS with SonoVue improves differentiation between malignant and benign FLLs, and also provides improved lesion type (differential) diagnosis.

Focal liver lesions: role of contrast-enhanced ultrasound

The introduction of microbubble contrast agents and the development of contrast-specific techniques have opened new possibilities in liver imaging. Initially, only intermittent imaging with Doppler detection was available. Second-generation contrast agents and low mechanical index real-time scanning techniques are decisive advances that enable convenient liver examinations with high sensitivity and specificity. Hepatic lesions usually show typical perfusion and enhancement patterns through the various contrast phases, which help their characterization. Several published studies and the daily clinical routine show that, as opposed to conventional ultrasound (US), contrast-enhanced US can substantially improve detection and differentiation of focal liver lesions. Today, contrast-enhanced US is the dynamic imaging modality of choice for differentiation of focal liver lesions. Contrast uptake patterns of the most relevant liver lesions, as well as important clinical indications are presented and discussed.

Hemorrhage control using high intensity focused ultrasound

Hemorrhage control is a high priority task in advanced trauma care, because hemorrhagic shock can result in less than a minute in cases of severe injuries. Hemorrhage was found to be solely responsible for 40-50% of traumatic civilian and battlefield deaths in recent years. The majority of these deaths were due to abdominal and pelvic injuries with hidden and inaccessible bleeding of solid organs such as liver, spleen, and kidneys, as well as major blood vessels. High intensity focused ultrasound (HIFU) offers a promising method for hemorrhage control. An important advantage of HIFU is that it can deliver energy to deep regions of tissue where hemorrhage is occurring, allowing cauterization at depth of parenchymal tissues, or in difficult-to-access anatomical regions, while causing no or minimal biological effects in the intervening and surrounding tissues. Moreover, HIFU can cause both thermal and mechanical effects that are shown to work synergistically for rapid hemorrhage control. The major challenges of this method are in development of bleeding detection techniques for accurate localization of the injury sites, delivery of large HIFU doses for profuse bleeding cases, and ensuring safety when critical structures are in the vicinity of the injury. Future developments of acoustic hemostasis technology are anticipated to be for applications in peripheral vascular injuries where an acoustic window is usually available, and for applications in the operating room on exposed organs.

Terminology for contrast-enhanced sonography: a practical glossary

OBJECTIVE

The purpose of this glossary is to offer an updated guide to the correct terminology for contrast-enhanced sonography.

METHODS

This report was prepared by a panel of radiologists from the Sonography Section of the Italian Association of Medical Radiology. A leading author prepared a list of terms based on a comprehensive literature survey. The draft was analyzed by 3 experts on the topic of contrast-enhanced sonography. These reviewers reached a consensus and prepared the final version.

RESULTS

A list of 137 terms is included. These terms are briefly defined. Their proper application is discussed, with special reference to potential misleading uses.

CONCLUSIONS

Contrast-enhanced sonography is a relatively new diagnostic tool, now entering clinical practice in several countries. Use of appropriate, universal terminology is mandatory in the scientific setting to allow comparison between different published experiences. Additionally, use of clear, standardized terminology is necessary in the clinical setting to facilitate report understanding by the referring physician. Standardized, nonequivocal nomenclature may also help future diffusion of sonographic contrast media in countries where their application is still not approved.

Transient hepatic echogenicity difference on contrast-enhanced ultrasonography: sonographic sign and pitfall

OBJECTIVE

The purpose of this study was to report and analyze a new contrast-enhanced ultrasonographic (CEUS) imaging finding, the transient hepatic echogenicity difference due to perfusion changes, using computed tomography (CT) as a reference standard.

METHODS

We retrospectively investigated the records of patients evaluated in a 2-year period, selecting those who had undergone both CT and CEUS within 15 days, who had CT evidence of a perfusion abnormality, and who had had a CEUS study that included the malperfused parenchymal area.

RESULTS

There were 30 patients with 44 hepatic perfusion changes on CT scans (28 around liver focal lesions and 16 unrelated to focal lesions). Retrospectively, CEUS allowed recognition of 21 of 28 perifocal transient hepatic attenuation differences (THADs), 6 of 10 subsegmental THADs, 2 of 3 segmental THADs, and 1 of 3 lobar THADs. Only some of these abnormalities had been identified at the original CEUS examinations: 0 of 3 lobar THADs, 1 of 3 segmental THADs, 2 of 10 subsegmental THADs, and 16 of 28 perifocal THADs.

CONCLUSIONS

Contrast-enhanced ultrasonography can show hepatic perfusion abnormalities similar to those well known from CT literature, although with a lower sensitivity. Knowledge of this transient hepatic echogenicity difference phenomenon may be relevant for avoiding incorrect image interpretation or incorrect tumor size measurement and for eventually identifying occult vascular disorders such as venous thrombosis or fistulas.

Tumor dormancy and the role of metastasis suppressor genes in regulating ectopic growth

Metastasis, or tumor growth in an ectopic site, may occur several years after apparently successful treatment of the primary malignancy. Clinical dormancy is seen in a large number of cancer patients, but once growth in an ectopic site initiates, current adjuvant therapies are inadequate and the majority of patients with metastatic disease will die. Many genes may regulate ectopic growth in a secondary site, including a small subset, termed the metastasis suppressor genes. Investigation into this class of genes holds promise in terms of gaining a greater understanding of tumor dormancy and how the process of metastasis may be naturally inhibited. This review will focus on the role of metastasis suppressor genes in tumor dormancy. Insights into the metastatic process from studies of metastasis suppressor genes may lead to novel targets for antimetastatic therapy through drug-induced reactivation of one or more of these genes and/or their respective signaling pathways.

Detection of bleeding in injured femoral arteries with contrast-enhanced sonography

OBJECTIVE

The purpose of this study was to investigate the feasibility of detecting acute arterial bleeding by means of contrast-enhanced sonography.

METHODS

Puncture injury was produced transcutaneously with an 18-gauge needle in 26 femoral arteries (13 in the control group and 13 in the contrast-enhanced group) of rabbits. A sonographic contrast agent (Optison; Mallinckrodt Inc, St Louis, MO) was administered intravenously at a dose of 0.06 to 0.07 mL/kg. Sonography of the femoral arteries was performed before and after injury, both before and after injection of Optison, with B-mode imaging, color Doppler imaging, and pulse inversion harmonic imaging (PIHI).

RESULTS

The specific location of active bleeding could not be visualized in B-mode and PIHI scans in the control group (no Optison injection). After administration of Optison, the bleeding site was visualized because of the increased echogenicity of the extravasated blood at the puncture site in both B-mode imaging and PIHI. In color Doppler images, bleeding sites were localized successfully in 84.6% of the cases in the presence of Optison and in 30.8% of the cases without Optison. Histologic examination (light microscopy) of the hematoma confirmed the presence of contrast agent microbubbles in the extravascular space surrounding the artery.

CONCLUSIONS

Contrast-enhanced sonography may provide an effective method for detecting arterial bleeding.

Blunt trauma to the spleen: ultrasonographic findings

The spleen is the most frequently injured organ in adults who sustain blunt abdominal trauma. Splenic trauma accounts for approximately 25% to 30% of all intra-abdominal injuries. The management of splenic injury has undergone rapid change over the last decade, with increasing emphasis on splenic salvage and non-operative management. Identifying the presence and degree of splenic injury is critical in triaging the management of patients. Imaging is integral in the identification of splenic injuries, both at the time of injury and during follow-up. Although CT remains the gold standard in blunt abdominal trauma, US continues to play an important role in assessing the traumatized spleen. This pictorial review illustrates the various ultrasonographic appearances of the traumatized spleen. Correlation with other imaging is presented and complications that occur during follow-up are described.