Real time contrast enhanced ultrasonography in detection of liver metastases from gastrointestinal cancer

Contrast-enhanced ultrasound with microbubbles containing sulfur hexafluoride and perfluorobutane with Kupffer phase for the detection of colorectal liver metastases

OBJECTIVE

To compare contrast-enhanced ultrasound (CEUS) with microbubbles containing sulfur hexafluoride (SHF) and perfluorobutane (PFB) for the detection of colorectal liver metastasis (CRLM).

METHODS

In this prospective study, conducted from September to November 2021, patients with colorectal cancer were consecutively recruited and underwent same-day ultrasound, SHF-CEUS, and PFB-CEUS. The reference standard was contrast-enhanced MRI and follow-up imaging. The size, depth, echogenicity, and calcification of each focal liver lesion were recorded. The number and conspicuity of CRLMs, based on washout appearance during the late phase (LP) (> 120 s)/Kupffer phase (KP), were evaluated offsite by two blinded readers.

RESULTS

Overall, 230 lesions (CRLMs, n = 219; benign lesions, n = 11) in 78 patients were evaluated. Lesion conspicuity (p = 0.344) and accuracy in the detection of CRLM were comparable for SHF- and PFB-CEUS (0.877 for SHF vs. 0.770 for PFB, p = 0.087). More CRLMs ≥ 10 mm were identified by LP contrast washout in SHF-CEUS than in KP PFB-CEUS (p < 0.001). More CRLMs < 10 mm were identified by KP washout in PFB-CEUS than in LP SHF-CEUS (p < 0.001). Conspicuity was better on PFB-CEUS than on SHF-CEUS (p = 0.027). In hyperechoic lesions, lesions located deeper than 80 mm, and calcified lesions, CRLM conspicuity on PFB-CEUS was inferior to that on SHF-CEUS (p < 0.05).

CONCLUSIONS

The overall accuracy of detection and conspicuity of washout in CRLMs were comparable between SHF and PFB-CEUS. PFB-CEUS has the advantage of identifying washout in small CRLMs. However, larger, hyperechogenic, deep-seated, or calcified lesions were better identified using SHF-CEUS.

CLINICAL RELEVANCE STATEMENT

Accuracy of detection and conspicuity of washout in CRLMs were comparable between SHF- and PFB-CEUS. PFB-CEUS has the advantage in detecting small CRLMs, whereas SHF-CEUS is better for detecting larger, hyperechogenic, deep-seated, or calcified lesions.

KEY POINTS

Contrast-enhanced ultrasound with sulfur hexafluoride in the late phase and perfluorobutane microbubbles in the Kupffer phase were comparable in terms of accuracy in the detection and conspicuity of colorectal liver metastases. Small colorectal liver metastases (< 10 mm) were more often identified in the Kupffer phase contrast-enhanced ultrasound imaging when using perfluorobutane microbubbles. Larger, hyperechogenic, deep-seated, or calcified lesions were better identified in the late phase contrast-enhanced ultrasound imaging (> 120 s) when using sulfur hexafluoride microbubbles.

Comparison of contrast-enhanced transabdominal ultrasonography following endoscopic ultrasonography with GD-EOB-DTPA-enhanced MRI for the sequential diagnosis of liver metastasis in patients with pancreatic cancer

PURPOSE

To compare contrast-enhanced transabdominal ultrasonography (CE-US) following contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) with enhanced magnetic resonance imaging using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (EOB-MRI) in the diagnosis of liver metastases in patients with pancreatic cancer.

METHODS

Patients who underwent contrast-enhanced computed tomography for possible pancreatic cancer and required further evaluation with CH-EUS were enrolled in this study, and the diagnostic performance of CE-US following CH-EUS for liver metastasis was compared with that of EOB-MRI.

RESULTS

A total of 228 patients were included in the final analysis. Two hundred thirty-four hepatic lesions were found in 81 patients, and 178 lesions were finally diagnosed as metastases. EOB-MRI had a higher sensitivity (0.837 vs 0.949), while CE-US had a higher specificity and positive predictive value (PPV) (0.982 and 0.993 vs 0.911 and 0.971, respectively) in the diagnosis of liver metastasis. CE-US with defect reperfusion imaging had a higher diagnostic performance than EOB-MRI (0.866 vs 0.667) in the differentiation between liver metastasis and abscess.

CONCLUSION

EOB-MRI had a higher sensitivity than CE-US for diagnosing liver metastasis in patients with pancreatic cancer, but CE-US following CH-EUS demonstrated a higher specificity and PPV than EOB-MRI and was especially useful in the differentiation between liver metastasis and abscess.

Radiological Imaging of Gastro-Entero-Pancreatic Neuroendocrine Tumors. The Review of Current Literature Emphasizing the Diagnostic Value of Chosen Imaging Methods

Despite development of radiologic imaging, detection and follow-up of neuroendocrine neoplasms (NENs) still pose a diagnostic challenge, due to the heterogeneity of NEN, their relatively long-term growth, and small size of primary tumor. A set of information obtained by using different radiological imaging tools simplifies a choice of the most appropriate treatment method. Moreover, radiological imaging plays an important role in the assessment of metastatic lesions, especially in the liver, as well as, tumor response to treatment. This article reviews the current, broadly in use imaging modalities which are applied to the diagnosis of GEP-NETs, (the most common type of NENs) and put emphasis on the strengths and limitations of each modality.

Contrast-enhanced ultrasound imaging of the liver: a review of the clinical evidence for SonoVue and Sonazoid

Contrast-enhanced ultrasound (CEUS) has become an established modality in various clinical indications for liver diseases. SonoVue^®, a pure blood pure agent, and Sonazoid^®, which exhibits an additional Kupffer phase, are contrast agents approved for liver imaging. This review discusses and compares the current clinical evidence for these two ultrasound contrast agents in the characterization and detection of focal liver lesions in the non-cirrhotic and cirrhotic liver, as well as for the use in interventional procedures such as liver biopsy guidance, and local ablation treatment monitoring. Reference is made to clinical studies which evaluated the accuracy of CEUS using a standard of reference, its safety, or to comparative studies of these two agents.

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver - Update 2020 - WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS), first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications.The 2012 guideline requires updating as previously the differences of the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including the United States Food and Drug Administration (FDA) approval as well as the extensive Asian experience, to produce a truly international perspective.These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCA) and are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis to improve the management of patients.

Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound (CEUS) in the Liver-Update 2020 WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast-enhanced ultrasound, first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology. The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications. The 2012 guideline requires updating as, previously, the differences in the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including U.S. Food and Drug Administration approval and the extensive Asian experience, to produce a truly international perspective. These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCAs) and are intended to create standard protocols for the use and administration of UCAs in liver applications on an international basis to improve the management of patients.

Diagnostic performance of contrast-enhanced ultrasound and magnetic resonance imaging for detecting colorectal liver metastases: A systematic review and meta-analysis

OBJECTIVES

To determine the diagnostic performance of contrast-enhanced ultrasound, diffusion-weighted magnetic resonance imaging and contrast-enhanced magnetic resonance imaging for detecting colorectal liver metastases.

METHODS

We performed comprehensive searches of the MEDLINE, EMBASE, and Cochrane Library databases to identify studies reporting the per-lesion diagnostic accuracy of contrast-enhanced ultrasound, diffusion-weighted magnetic resonance imaging, and contrast-enhanced magnetic resonance imaging for detecting colorectal liver metastases. Studies published between January 2003 and December 2018 with reference standards, including histopathology and intraoperative observation, and/or follow-up, were included. Sources of bias were assessed using the QUADAS-2 tool. A linear mixed-effects regression model was used to determine sensitivity estimates.

RESULTS

Overall, 47 articles were included. The sensitivity estimates for contrast-enhanced ultrasound, diffusion-weighted magnetic resonance imaging, and contrast-enhanced magnetic resonance imaging for detecting colorectal liver metastases were 85.3%, 83.0%, and 90.1%, respectively. For lesions ≥10 mm in diameter, the sensitivities were 93.1%, 92.9%, and 94.5%, respectively. In 21 articles using histopathology as the only reference standard, the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for contrast-enhanced ultrasound/contrast-enhanced magnetic resonance imaging were 86%/91%, 91%/95%, 9.2/16.6, 0.15/0.10, and 61/170, respectively.

CONCLUSIONS

CEUS showed a diagnostic ability comparable to that of DWI and CEMRI, particularly for lesions ≥10 mm in diameter.

A radiologist's point of view in the presurgical and intraoperative setting of colorectal liver metastases

Multidisciplinary management of patients with metastatic colorectal cancer requires in each phase an adequate choice of the most appropriate imaging modality. The first challenging step is liver lesions detection and characterization, using several imaging modality ultrasound, computed tomography, magnetic resonance and positron emission tomography. The criteria to establish the metastases resectability have been modified. Not only the lesions number and site but also the functional volume remnant after surgery and the quality of the nontumoral liver must be taken into account. Radiologists should identify the liver functional volume remnant and during liver surgical procedures should collaborate with the surgeon to identify all lesions, including those that disappeared after the therapy, using intraoperative ultrasound with or without contrast medium.

Role of contrast-enhanced ultrasound to define prognosis and predict response to biotherapy in pancreatic neuroendocrine tumors

PURPOSE

The incidence of neuroendocrine tumors (NETs) is progressively increasing. Most cases arise from the digestive system, where ileum, rectum and pancreas represent the commonest site of origin. Liver metastases are frequently detected at diagnosis or during the follow-up. Contrast-enhanced ultrasound (CEUS) is used in patients with pancreatic NETs (P-NETs) and liver metastases from P-NET but its role has not been standardized. The aim of this retrospective study was to investigate CEUS in patients with P-NETs and liver metastases from P-NET both as prognostic factor and predictor of response to therapy with somatostatin analogues (SSAs).

METHODS

CEUS was performed at the diagnosis of NET and 3, 6 and 12 months after the beginning of SSAs. CEUS pattern was compared with contrast-enhanced computed tomography (CT) pattern.

RESULTS

There was a significant association between CEUS and CT pattern (X ² = 79.0; p < 0.0001). A significant association was found between CEUS pattern and Ki-67 index (X ² = 24.6; p < 0.0001). The hypervascular homogeneous CEUS typical pattern was associated with low tumor grading (G1 or G2) (X ² = 24.0; p < 0.0001). CEUS pattern changed from hypervascular homogeneous in baseline to hypovascular/hypervascular inhomogeneous after SSA therapy, with a significant association between tumor response at CT scan and appearance of hypervascular inhomogeneous pattern at CEUS evaluation (6 months: X ² = 57.0; p < 0.0001; 12 months: X ² = 49.8; p < 0.0001).

CONCLUSIONS

In patients with P-NET, CEUS pattern correlates with tumor grading, being homogeneous in G1-G2 but not in G3 tumors. After therapy with SSAs, CEUS is predictive of response to SSAs. These findings seem to support a role of CEUS as prognostic and predictive factor of response.

Single-center nonrandomized clinical trial to assess the safety and efficacy of irreversible electroporation (IRE) ablation of liver tumors in humans: Short to mid-term results

INTRODUCTION

A single-center nonrandomized clinical trial was performed to assess the safety and efficacy of IRE ablation of liver tumors in humans.

METHODS

38 malignant liver tumors on 30 patients were treated with IRE between September 2011 and September 2014. Treatment was with curative intent, and the diagnoses were colorectal cancer with liver metastases (CRLM) (n = 23), hepatocellular carcinoma (HCC) (n = 8) and other metastasis (n = 7). Patients were selected when surgery, radiofrequency ablation (RFA) or microwave ablation (MWA) was not an option, and when they met inclusion criteria (tumor size < 3 cm, 1-2 tumors). Patients were followed-up at 1 and 6 months with a contrast-enhanced computed tomography (CE-CT), and contrast-enhanced ultrasound (CE-US) at 3 months.

RESULTS

Ablation success was defined as no evidence of residual tumor in the ablated area as confirmed by CE-CT and CE-US. At 3 months ablation success was 78.9%, and 65.8% at 6 months. There was no statistically significant difference between tumor volume (<5 cm³ vs >5 cm³, p = 0.518), and between diagnosis (CRLM vs HCC, p = 0.084) in terms of local recurrence. Complications were classified according to the standardized grading system of Society of Interventional Radiology (SIR). A minor complication occurred in six patients (20%), one patient (3.3%) suffered from a major complication (bile duct dilatation and stricture of the portal vein and bile duct). No mortalities occurred at 30 days.

CONCLUSIONS

IRE appears to be a safe treatment modality for a selected group of patients with liver tumors and offers high local tumor control at 3 and 6 months.

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

BACKGROUND/AIMS

To evaluate the enhancement patterns of liver metastases and their influencing factors using dynamic contrast-enhanced ultrasound (CEUS).

METHODS

A total of 240 patients (139 male and 101 female; 58.5 ± 11.2 years of age) diagnosed with liver metastases in our hospital were enrolled in this study to evaluate tumor characteristics using CEUS. A comparison of enhancement patterns with tumor size and primary tumor type was performed using the chi-square test. The differences between quantitative variables were evaluated with the independent-sample t-test and one-way analysis of variance.

RESULTS

The enhancement patterns of liver metastases on CEUS were categorized as diffuse homogeneous hyperenhancement (133/240, 55.4%), rim-like hyperenhancement (80/240, 33.3%), heterogeneous hyperenhancement (10/240, 4.2%), and isoenhancement (17/240, 7.1%). There were significant differences in the enhancement patterns during the arterial phase based on the nodule size (p=0.001). A total of 231 of the nodules showed complete washout during the portal phase, and 237 nodules were hypoenhanced during the delayed phase. The washout time was correlated with tumor vascularity, with a longer washout time observed in hypervascular metastases compared to hypovascular metastases (p=0.033).

CONCLUSIONS

Diffuse homogeneous hyperenhancement followed by rapid washout was the most common enhancement pattern of liver metastases on CEUS and was affected by the nodule size and tumor vascularity. Small metastases were prone to show diffuse homogeneous hyperenhancement. Hypervascular metastases showed a significantly longer washout time compared to hypovascular metastases.

Preoperative detection of hepatic metastases from colorectal cancer: Prospective comparison of contrast-enhanced ultrasound and multidetector-row computed tomography (MDCT)

PURPOSE

The goal of this study was to prospectively compare the sensitivity of contrast-enhanced ultrasound (CEUS) with that of multiphase multidetector-row computed tomography (MDCT) in the preoperative detection of hepatic metastases.

MATERIALS AND METHOD

Forty-eight patients, with a mean age of 62years old (range: 43-85years) were prospectively included. All patients underwent CEUS following intravenous administration of 2.4mL of an ultrasound contrast agent (Sonovue(®), Bracco, Milan, Italy) and multiphase MDCT. Intraoperative ultrasound examination (IOUS) was used as the standard of reference.

RESULTS

A total of 158 liver metastases were identified by IOUS, 127 by preoperative MDCT (sensitivity; 80.4%) and 102 by CEUS (sensitivity, 64.5%). The 15.9% difference in sensitivity between CEUS and MDCT was statistically significant (P=0.002). There was a disagreement between IOUS and CEUS in 23 patients (47%) and in 13 patients (27%) between IOUS and MDCT. MDCT identified one or more additional metastases in 10 patients (20%) resulting in a change in the surgical strategy.

CONCLUSION

Based on an unselected patient cohort and using multiphase MDCT, CEUS is significantly inferior to MDCT for the preoperative detection of hepatic metastases of colorectal cancer.

The prediction of survival of patients with gastric cancer with PD-L1 expression using contrast-enhanced ultrasonography

Gastric cancer is the one of the most common cancers around the world. The prognosis of gastric cancer remains poor, due to the biological characteristics of the primary tumor as well as the recurrence after treatment. Accumulating evidence suggests the implication of programmed death ligand-1 (PD-L1) in the pathogenesis and prognosis of cancer. This study aimed to explore the CEUS as a valuable tool to improve the assessment of the therapeutic effect of the PD-L1 blocker in the treatment of gastric cancer. A total number of 105 patients with gastric cancer were enrolled in this study from June 2008 to December 2011 in our hospital. The association of PD-L1 expression level (105 cases) and CEUS parameters (100 cases) with the prognosis of gastric cancer was examined. The results showed that PD-L1-positive staining was associated with the depth of invasion, differentiation, and poor prognosis of patients with gastric cancer. The CEUS intensity (positive) exhibited poor prognosis compared to the negative counterpart. Moreover, PD-L1 and CEUS co-positivity was significantly related to a poor prognosis. The characteristic of ultrasonography images correlated with the expression of PD-L1 (r = 0.46, P = 0.0003). Collectively, the mean intensity of contrast-enhanced ultrasonography is a useful predictor in the PD-L1 expression in gastric cancer. The ultrasonography and CEUS parameter could be considered as the predictor of response to PD-L1 blocker treatment in the clinical practice.

Liver Contrast-Enhanced Ultrasound Improves Detection of Liver Metastases in Patients with Pancreatic or Periampullary Cancer

The aim of this study is to provide a diagnostic performance evaluation of contrast-enhanced ultrasonography (CEUS) in detecting liver metastases in patients with suspected of pancreatic or periampullary cancer. Computed tomography (CT) is often insufficient for detection of liver metastases, but their presence plays a crucial role in the choice of therapy. Eighty-nine patients with suspected pancreatic or periampullary cancer were included in this prospective study with retrospective analysis. Patients underwent an abdominal CT and CEUS. Fifteen patients had liver metastases. The CT sensitivity was 73.3% (11/15), the specificity 93.2% (69/74), the positive predictive value (PPV) 68.8% (11/16) and the negative predictive value (NPV) 94.6% (69/73). Based on CEUS, the sensitivity was 80% (12/15), specificity 98.6% (73/74), PPV 92.3% (12/13) and NPV 96.1% (73/76). CEUS improved characterization of liver lesions in patients with suspected pancreatic or periampullary cancer compared with CT. CEUS can better detect benign liver lesions and distinguish false-positive or indeterminate CT results.

New approaches to gastric cancer staging: Beyond endoscopic ultrasound, computed tomography and positron emission tomography

Currently, there is no single gold standard modality for staging of gastric cancer and several methods have been used complementarily in the each clinical situation. To make up for the shortcomings of conventional modalities such as endoscopic ultrasound, computed tomography and ¹⁸F-fluoro-2-deoxyglucose positron emission tomography, numerous attempts with new approaches have been made for gastric cancer staging. For T staging, magnifying endoscopy with narrow-band was evaluated to differentiate mucosal cancer from submucosal cancer. Single/double contrast-enhanced ultrasound and diffusion-weighted magnetic resonance imaging were also tried to improve diagnostic accuracy of gastric cancer. For intraoperative staging with sentinel node mapping, indocyanine green infrared and fluorescence imaging was introduced. In addition, to detect micrometastasis, real-time reverse transcription-polymerase chain reaction system with multiple markers was studied. Staging laparoscopy using 5-aminolevulinic acid-mediated photodynamic diagnosis and percutaneous diagnostic peritoneal lavage were also evaluated. However, most studies reporting new staging methods is preliminary and further studies for validation in clinical practice are needed. In this mini-review, we discuss new progress in gastric cancer staging. Especially, we focus on new diagnostic approach to gastric cancer staging beyond the conventional modalities and briefly review the remarkable clinical results of the studies published over the past three years.

Evaluation of contrast Sonazoid-enhanced ultrasonography for the detection of hepatic metastases in breast cancer

Background

The present study was aimed to evaluate the usefulness of contrast Sonazoid-enhanced ultrasonography (US) for the detection of hepatic metastases in breast cancer patients and compare the clinical efficacy and sensitivity of this technique with conventional contrast unenhanced B-mode US in follow-up examinations of breast cancer patients with liver metastasis.

Methods

We assessed a total of 84 hepatic tumors from 24 patients diagnosed with or suspected of having metastatic cancer. These hepatic nodules were diagnosed through imaging, including dynamic magnetic resonance imaging (MRI), contrast-enhanced computed tomography (CECT) scan, B-mode US or contrast Sonazoid-enhanced US (SEUS). Differences in the sensitivity between US and SEUS were compared using MR imaging, CECT, and follow-up imaging.

Results

A total of 79 nodules were diagnosed as metastatic tumors. The remaining nodules were diagnosed as benign tumors (hepatic hemangioma: n = 3; local fatty change: n = 2). SEUS precisely detected the presence or absence of hepatic tumors in the 24 patients examined, showing a sensitivity of 98.8 % (83 of 84 lesions) for total imaged solid liver lesions, with an accuracy of 98.7 % (78 of 79 lesions) for total metastatic breast cancer lesions. In contrast, conventional B-mode US imaging revealed hepatic tumor lesions at a sensitivity of 66.7 % (56 of 84 lesions) and an accuracy of 64.6 % (51 of 79 lesions), respectively. Furthermore, the false positive and false negative rates were, respectively, 6.33 and 29.1 % for B-mode US and 0 and 1.3 % for SEUS. Moreover, twenty-seven metastatic tumors and five benign lesions (3 hemangiomas and 2 focal fatty changes/sparings) were imaged using SEUS but not conventional B-mode US. Significant differences in diagnostic accuracy rates between contrast Sonazoid-enhanced US and conventional B-mode US were observed (Wilcoxon signed rank test: p = 0.0009). No severe adverse events occurred during SEUS after the administration of Sonazoid, except for a grade 1 skin reaction and nausea in one patient.

Conclusion

These results suggested that Sonazoid could be safely administrated to breast cancer patients with liver metastatic disease. Thus, contrast Sonazoid-enhanced US is a feasible and more effective method than B-mode US for the detection of hepatic metastasis, particularly for small metastatic breast cancer lesions less than 14 mm in diameter, showing significant high sensitivity and accuracy.

Liver metastases: Contrast-enhanced ultrasound compared with computed tomography and magnetic resonance

The development of ultrasound contrast agents with excellent tolerance and safety profiles has notably improved liver evaluation with ultrasound (US) for several applications, especially for the detection of metastases. In particular, contrast enhanced ultrasonography (CEUS) allows the display of the parenchymal microvasculature, enabling the study and visualization of the enhancement patterns of liver lesions in real time and in a continuous manner in all vascular phases, which is similar to contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance imaging. Clinical studies have reported that the use of a contrast agent enables the visualization of more metastases with significantly improved sensitivity and specificity compared to baseline-US. Furthermore, studies have shown that CEUS yields sensitivities comparable to CT. In this review, we describe the state of the art of CEUS for detecting colorectal liver metastases, the imaging features, the literature reports of metastases in CEUS as well as its technique, its clinical role and its potential applications. Additionally, the updated international consensus panel guidelines are reported in this review with the inherent limitations of this technique and best practice experiences.

Palliative care and end-stage colorectal cancer management: The surgeon meets the oncologist

Colorectal cancer (CRC) is a common neoplasia in the Western countries, with considerable morbidity and mortality. Every fifth patient with CRC presents with metastatic disease, which is not curable with radical intent in roughly 80% of cases. Traditionally approached surgically, by resection of the primitive tumor or stoma, the management to incurable stage IV CRC patients has significantly changed over the last three decades and is nowadays multidisciplinary, with a pivotal role played by chemotherapy (CHT). This latter have allowed for a dramatic increase in survival, whereas the role of colonic and liver surgery is nowadays matter of debate. Although any generalization is difficult, two main situations are considered, asymptomatic (or minimally symptomatic) and severely symptomatic patients needing aggressive management, including emergency cases. In asymptomatic patients, new CHT regimens allow today long survival in selected patients, also exceeding two years. The role of colonic resection in this group has been challenged in recent years, as it is not clear whether the resection of primary CRC may imply a further increase in survival, thus justifying surgery-related morbidity/mortality in such a class of short-living patients. Secondary surgery of liver metastasis is gaining acceptance since, under new generation CHT regimens, an increasing amount of patients with distant metastasis initially considered non resectable become resectable, with a significant increase in long term survival. The management of CRC emergency patients still represents a major issue in Western countries, and is associated to high morbidity/mortality. Obstruction is traditionally approached surgically by colonic resection, stoma or internal by-pass, although nowadays CRC stenting is a feasible option. Nevertheless, CRC stent has peculiar contraindications and complications, and its long-term cost-effectiveness is questionable, especially in the light of recently increased survival. Perforation is associated with the highest mortality and remains mostly matter for surgeons, by abdominal lavage/drainage, colonic resection and/or stoma. Bleeding and other CRC-related symptoms (pain, tenesmus, etc.) may be managed by several mini-invasive approaches, including radiotherapy, laser therapy and other transanal procedures.

Continuous dynamic registration of microvascularization of liver tumors with contrast-enhanced ultrasound

Aim. To evaluate the diagnostic value of quantification of liver tumor microvascularization using contrast-enhanced ultrasound (CEUS) measured continuously from the arterial phase to the late phase (3 minutes). Material and Methods. We present a retrospective analysis of 20 patients with malignant (n = 13) or benign (n = 7) liver tumors. The tumors had histopathologically been proven or clearly identified using contrast-enhanced reference imaging with either 1.5 T MRI (liver specific contrast medium) or triphase CT and follow-up. CEUS was performed using a multifrequency transducer (1–5 MHz) and a bolus injection of 2.4 mL sulphur hexafluoride microbubbles. A retrospective perfusion analysis was performed to determine TTP (time-to-peak), RBV (regional blood volume), RBF (regional blood flow), and Peak. Results. Statistics revealed a significant difference (P < 0.05) between benign and malignant tumors in the RBV, RBF, and Peak but not in TTP (P = 0.07). Receiver operating curves (ROC) were generated for RBV, RBF, Peak, and TTP with estimated ROC areas of 0.97, 0.96, 0.98, and 0.76, respectively. Conclusion. RBV, RBF, and Peak continuously measured over a determined time period of 3 minutes could be of valuable support in differentiating malignant from benign liver tumors.

Shear wave elastography in the evaluation of liver fibrosis in children

BACKGROUND

Shear-wave elastography (SWE) is a novel noninvasive method that involves application of local mechanical compression on soft tissue using focused ultrasonography and acquiring strain images that show tissue response. In this study, our goal was to assess the performance of SWE in the staging of liver fibrosis in children with chronic liver disease.

METHODS

The study involved measuring SWE values in the right lobe of the liver in a patient group of 76 children with chronic liver disease and a control group of 50 healthy subjects. In the patient group, the shear elastic modulus values were correlated with biopsy results according to the Brunt scoring system (F0: portal fibrosis, F1: perisinusoidal or portal/periportal fibrosis, F2: both perisinusoidal and portal/periportal fibrosis, F3: bridging fibrosis, and F4: cirrhosis). Performance of SWE in estimating liver fibrosis in children was determined based on a receiver-operating characteristics (ROC) analysis.

RESULTS

Mean SWE values of the control group and F0 group were not statistically significantly different (P = 0.106). The mean SWE values of the F1, F2, F3, and F4 groups were higher than that of the control group (all P < 0.001). Based on kiloPascal measurement values, the area under the ROC curve was 95.2% (95% confidence interval [CI] 92.1-99.5), with a sensitivity for diagnosing liver fibrosis of 91.5%, a specificity of 94.0%, a positive predictive value of 93.1%, and a negative predictive value of 92.6%. Based on meter-per-second measurement values, the area under the ROC curve was 96.3% (95% CI 92.7-99.8), with a sensitivity for diagnosing liver fibrosis of 93.2%, a specificity of 94.0%, a positive predictive value of 93.2%, and a negative predictive value of 94.0%. Mean SWE values for patients with nonalcoholic steatohepatitis were higher than those in the remainder of the study group.

CONCLUSIONS

Although liver fibrosis can be detected using SWE, differentiation of fibrosis stages could not be achieved. The presence of steatosis significantly increased the mean SWE values on elastography and so care should be taken when assessing children with nonalcoholic steatohepatitis.

Guidelines and good clinical practice recommendations for Contrast Enhanced Ultrasound (CEUS) in the liver - update 2012: A WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

Double contrast-enhanced two-dimensional and three-dimensional ultrasonography for evaluation of gastric lesions

AIM: To investigate the value of two-dimensional (2D) and three-dimensional (3D) double contrast-enhanced ultrasonography (DCUS) imaging for evaluation of gastric lesions.

METHODS: 2D and 3D DCUS imaging with both oral and intravenous administrations of contrast agents was used to assess gastroscopiclly-confirmed gastric lesions in 46 patients with benign and malignant diseases. Initially, liquid-based ultrasound contrast agent (Xinzhang^®) was given orally at dose of 500-600 mL for conventional ultrasound examination of the gastric lesions, and then a microbubble-based contrast agent (SonoVue) was injected intravenously at dose of 1.2-2.4 mL in bolus fashion to assess the perfusion pattern of the lesions using contrast imaging modes. The parameters derived from time-intensity curves including the arrival time (AT), time to peak (TTP), peak intensity (PI) and enhanced intensity (EI) were measured on the 2D DCUS imaging. 3D DCUS of the lesions was acquired to demonstrate the value of this imaging mode.

RESULTS: There were 22 cases with benign lesions including chronic gastritis (n = 5), gastric ulcer (n = 9), gastric polyps (n = 3), gastric stromal tumors (n = 5), and 24 cases with malignant lesions including gastric cancer (n = 20), gastric cardia carcinoma (n = 3) and post-operative recurrent gastric cancer (n = 1) in the study. The oral contrast-enhanced ultrasonography (CEUS) imaging of the stomach clearly demonstrated the anatomy of the stomach and morphologic features of gastric lesions. With optimal scanning window and imaging display under oral CEUS, intravenous CEUS clearly showed the perfusion of gastric lesions with various characteristic manifestations. Both 2D and 3D DCUS images clearly demonstrated normal gastric wall as a three-layer structure, from the inside out, hyperechoic mucosa, hypoechoic muscularis and hyperechoic serosa, respectively. There were statistical significant differences of AT (8.68 ± 2.06 vs 10.43 ± 2.75, P = 0.017), PI (34.64 ± 6.63 vs 29.58 ± 8.22, P = 0.023) and EI (29.72 ± 6.69 vs 22.66 ± 7.01, P = 0.001) between malignant lesions and normal gastric wall. However, no differences of AT, PI and EI between benign lesions and normal gastric wall tissue were found. 3D DCUS could intuitively display morphological features and vascularities of the lesions with multiplanar and volume views. 3D DCUS imaging provided comprehensive information complementary to 2D imaging. The crater or wellhead appearances and feeding vessels as well as distorted nourishing vasculature of gastric carcinoma were better seen with 3D imaging than 2D imaging.

CONCLUSION: DCUS imaging can simultaneously display the anatomic and perfusion features of gastric lesions. 3D DCUS can provide additional information to 2D DCUS for evaluation of gastric lesions.

Elastographic assessment of liver fibrosis in children: A prospective single center experience

BACKGROUND

The assessment of liver damage in various disease states relies on a combination of clinical findings, biochemical parameters and invasive tests such as liver biopsy. The ultrasound elastography has emerged as a potential alternative test, providing quantifiable information on the elasticity/stiffness of the examined-tissues. We assessed the performance of ultrasound elastography using real-time Acoustic Radiation Force Imaging (ARFI) technology in evaluating the degree of liver fibrosis in children with and without liver disease.

METHODS

Children aged 0-18 years, hospitalized in the Emergency Clinical County Hospital Tg. Mures, Romania, between September 15, 2010 and January 15, 2011, were eligible for the study. Four groups were recruited as follow: patients with liver disease in the setting of various malignant disorders, children with non-malignant liver disease, overweight and obese children and healthy controls. The liver tissue elasticity was assessed in each individual using Shear Wave Velocity (SWV). Biochemical tests included transaminase levels. 19 children with chronic liver disease underwent biopsies. SWV was measured globally and separately for the liver-segments 1 and 8. Correlations between the SWV and laboratory test were established using non-parametric Spearman correlation test.

RESULTS

A total of 103 children underwent liver ultrasound elastographic assessments. Of these, 39 had malignancies, 19 had various chronic liver diseases, 13 had nonalcoholic fatty liver disease (NAFLD), and 32 were healthy controls. The transaminase values differed significantly between children with liver diseases and controls. In normal controls SWV values in the 1st segment were significantly lower compared to those in the in 8th segment of the liver (p=0.0216). In the group with hepatic steatosis, the SWV values were statistically higher compared to those in healthy controls. Positive statistical correlations have been established between AST and SWV in the group of children with NAFLD and those with malignancies (p=0.0032, p=0.0045).

CONCLUSIONS

Quantification of liver fibrosis by ARFI method correlates with the histological fibrosis stage in children with chronic liver disease and NAFLD. Clinical applications of this method in the diagnosis of pediatric liver disease deserve further study.

Clinical trials in gastric cancer and the future

Following the first successful gastric resection for gastric cancer by Theodor Billroth in 1881 surgery has made tremendous progress leading to improved surgical mortality and morbidity. However, while treatment of early gastric cancer is frequently curative, 5-year survival rates for advanced gastric cancer remain dismal despite the application of perioperative multimodal treatment concepts. In this article we will outline key clinical trials that have lead to an improvement in treatment of gastric cancer patients with specific emphasis on the last 20 years. We will then outline recent concepts and key clinical trials that are currently being conducted in the field. Finally we will outline open questions that remain to be elucidated in the future.

[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 ultrasound vs multidetector-computed tomography for detecting liver metastases in colorectal cancer: a prospective, blinded, patient-by-patient analysis

AIM

This study compared the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer.

METHOD

Between September 2004 and December 2008, 271 consecutive patients (146 men and 125 women; median age 68 years, range: 34-91 years) with primary colorectal cancer were evaluated. All underwent combined liver ultrasound and CEUS following intravenous injection of 2.4 ml of SonoVue(TM). The interval from injection to arrival time in the hepatic vein (ATHV) was noted. Contrast-enhanced MDCT in the portal phase was performed and interpreted blindly. In all patients, intra-operative ultrasound was used as the reference point. In addition, magnetic resonance imaging (MRI) or biopsy was performed on all suspicious lesions or if there was inconsistency in the results.

RESULTS

Liver metastases were detected in 21 (8%) patients. Both CEUS and MDCT had a sensitivity of 85.7%, with respective specificities of 97.6% and 95.6%, and positive predictive values of 75%vs 62%. The negative predictive value of both methods was 99%. In patients with and without liver metastases, ATHV was 18 and 22 s, respectively (P < 0.05).

CONCLUSION

CEUS has potential as a diagnostic alternative to MDCT in the detection of liver metastases. ATHV was shorter in patients with liver metastases.

[Diagnostic imaging in oncology--evidence reviews for evidence based guidelines by the Agency of Quality for Medicine (ÄZQ)]

Within the context of the development of evidence-based oncology guidelines, the Agency for Quality in Medicine undertook evidence reviews for diagnostic imaging procedures. Systematic searches retrieved no randomised controlled trials, but only cohort studies and case series of mostly moderate quality. The identified studies provided only a restricted basis for the guideline recommendations as their validity was limited and only outcomes of diagnostic accuracy were examined. However, decision criteria for recommending diagnostic strategies significantly comprise judgements about required resources and availability of diagnostic imaging procedures. These criteria as well as patient out-comes were mostly implicit and should be explicated in future. In order to increase the relevance of evidence reviews for oncological diagnosis, high quality studies which examine resources and patient-centred outcomes for diagnostic strategies are required.

Liver metastases: Sulphur hexafluoride-enhanced ultrasonography for lesion detection: a systematic review

This is a systematic review to evaluate the accuracy of contrast-enhanced ultrasonography (CEUS) performed with "SonoVue" (sulphur hexafluoride) in the detection of hepatic metastases. The MEDLINE, EMBASE and COCHRANE Databases were searched, regardless of language, for relevant articles published before December 2009. Two reviewers independently assessed study eligibility using a standardized form and methodological quality using the quality assessment of diagnostic accuracy studies (QUADAS) Checklist. Sensitivity estimates were calculated on a per-patient and/or per-lesion basis. The search for published articles yielded 718 potentially relevant abstracts. Of these, 14 papers were eligible but only three articles fulfilled the inclusion criteria, which comprised a total of 450 patients (patient sample number: range 12 to 365; cancer prevalence: 14.8 to 71.2%). Estimated per-patient sensitivity ranged from 79-100%. Although the quality assessment of diagnostic accuracy studies checklist showed the papers were of good quality, a meta-analysis was not applicable because of the lack of eligible studies. In conclusion, CEUS seems to be promising in the detection of liver metastases; however, there have not been enough studies to conduct meta-analysis. Further studies are required before this promising method can be widely used.

Contrast-enhanced ultrasonography in evaluating hepatic metastases from neuroendocrine tumours

OBJECTIVES

At presentation, gastroenteropancreatic neuroendocrine tumours (GEP NETs) frequently show prognostically negative hepatic involvement. The aim of this study was to characterise hepatic metastases of GEP NETs as revealed by contrast-enhanced ultrasonography (CEUS), which allows the fine definition of the microvascular system, and to correlate these findings to the biological behaviour of the tumour.

METHODS

Eighteen out of 62 GEP NET patients examined between January 2007 and September 2008 had histologically proven hepatic metastases from primary ileal (#6), gastric (#1) or rectal (#1) carcinoids, pancreatic tumours (#7), or primary duodenal (#2) or occult gastrinomas (#1), and all underwent low mechanical index real-time CEUS with SonoVue injection.

RESULTS

Strong early enhancement in the arterial phase was observed in 15 cases (83%), and a rapid wash-out in the portal venous phase in 14 (78%). In the late venous phase, the lesions were hypoechoic in 12 cases (67%), isoechoic in five (28%), and hyperechoic in one (0.05%). The time of arterial enhancement correlated with the Ki-67 proliferative index (r(s)=0.516; p=0.028).

CONCLUSIONS

Most of the neuroendocrine liver metastases showed increased arterial enhancement at CEUS, a behaviour that is similar to that of hepatocellular carcinomas and the opposite of that of other metastases. CEUS can be a useful diagnostic means of characterising such metastases.

Role of contrast enhanced ultrasonography in the assessment of hepatic metastases: A review

Contrast enhanced ultrasonography (CEUS) has improved both the detection and characterization of focal liver lesions. It is now possible to evaluate in real time the perfusion of focal liver lesions in the arterial, portal and late contrast phases, and thus to characterize focal liver lesions with high diagnostic accuracy. As a result, CEUS has taken a central diagnostic role in the evaluation of focal liver lesions that are indeterminate upon computed tomography (CT) and magnetic resonance imaging. The combined use of second generation contrast agents and low mechanical index techniques is essential for the detection of liver metastases, and it now allows the examination of the entire liver in both the portal and late phases. Several studies have shown that using CEUS instead of conventional ultrasonography without contrast agents significantly improves sensitivity in detection of liver metastases. Furthermore, the detection rate with CEUS seems to be similar to that of CT. This review describes the clinical role of CEUS in detecting liver metastases, including details about examination techniques, features of metastases observed with CEUS, and clinical results and guidelines.

Detection of hepatic metastases from carcinoid tumor: prospective evaluation of contrast-enhanced ultrasonography

The purpose of our study was to prospectively compare unenhanced ultrasonography (US) to contrast-enhanced US (CEUS) in the detection of hepatic metastases from carcinoid tumor. Thirty patients with carcinoid tumor prospectively underwent US, CEUS, and magnetic resonance imaging (MRI). Differences in sensitivity at US and CEUS were compared using a combination of the results of MR imaging, fine-needle biopsy, and follow-up imaging. Lesion conspicuity was assessed subjectively for US and CEUS. Seventeen patients had a total of 69 hepatic metastases. The addition of CEUS improved the detection of individual metastases from 47 (Se 68%; 95% CI: 57.0, 79.0) to 68 (Se 99%; 99% CI: 96.7, 100.0). Contrast enhancement improved the subjective conspicuity of metastases in 85% of patients. CEUS showed one more metastasis than did MRI in one patient, and MRI showed one more than did CEUS in one patient. CEUS is more sensitive than US in the detection of carcinoid liver metastases.

[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.

Imaging hemodynamics

Microvascular permeability is a pharmacologic indicator of tumor response to therapy, and it is expected that this biomarker will evolve into a clinical surrogate endpoint and be integrated into protocols for determining patient response to antiangiogenic or antivascular therapies. This review discusses the physiological context of vessel permeability in an imaging setting, how it is affected by active and passive transport mechanisms, and how it is described mathematically for both theoretical and complex dynamic microvessel membranes. Many research groups have established dynamic-enhanced imaging protocols for estimating this important parameter. This review discusses those imaging modalities, the advantages and disadvantages of each, and how they compare in terms of their ability to deliver information about therapy-associated changes in microvessel permeability in humans. Finally, this review discusses future directions and improvements needed in these areas.

Small liver lesions in oncologic patients: characterization with CT, MRI and contrast-enhanced US

Focal liver lesions (FLLs) are frequently discovered during ultrasound examinations either in healthy subjects without a clinical history of cancer or during staging or follow-up procedures in oncologic patients or in routine surveillance of hepatopathic patients. In oncologic patients, the liver is the most common target of metastatic disease and accurate detection and characterisation of FLLs is prognostically fundamental during the initial staging as well as before and after pre-operative chemotherapy, as it can help to identify patients who are most likely to benefit from liver surgery. Moreover, early detection of primary or secondary liver malignancies increases the possibility of curative surgical resection or successful percutaneous ablation. As many FLLs in these patients are benign, a precise and preferably non-invasive method of differentiation from malignant metastatic nodules is needed. Moreover, the continuous follow-up of cancer patients requires an easily available, reliable and cost-effective diagnostic tool for the detection and characterization of FLLs.