Shear wave elastography of the liver - review on normal values.

Shear wave elastography (SWE) has been developed to non-invasively estimate liver stiffness. Different techniques are available and they are described in detail in the EFSUMB guidelines on elastography. However, there are only a few published studies investigating normal ranges in healthy subjects by comparing different equipment and analysing influencing factors. In the present review, we summarize the impact factors on liver stiffness measurement (LSM) using SWE, report its reproducibility, and define normal range tables of LSM in healthy subjects for clinical practice according to the published literature.

Point of Care Ultrasound: A WFUMB Position Paper.

Over the last decade, the use of portable ultrasound scanners has enhanced the concept of point of care ultrasound (PoC-US), namely, "ultrasound performed at the bedside and interpreted directly by the treating clinician." PoC-US is not a replacement for comprehensive ultrasound, but rather allows physicians immediate access to clinical imaging for rapid and direct solutions. PoC-US has already revolutionized everyday clinical practice, and it is believed that it will dramatically change how ultrasound is applied in daily practice. However, its use and teaching are different from continent to continent and from country to country. This World Federation for Ultrasound in Medicine and Biology position paper discusses the current status and future perspectives of PoC-US. Particular attention is given to the different uses of PoC-US and its clinical significance, including within emergency and critical care medicine, cardiology, anesthesiology, rheumatology, obstetrics, neonatology, gynecology, gastroenterology and many other applications. In the future, PoC-US will be more diverse than ever and be included in medical student training.

Ultrasound-guided central vascular interventions, comments on the European Federation of Societies for Ultrasound in Medicine and Biology guidelines on interventional ultrasound.

Central venous access has traditionally been performed on the basis of designated anatomical landmarks. However, due to patients' individual anatomy and vessel pathology and depending on individual operators' skill, this landmark approach is associated with a significant failure rate and complication risk. There is substantial evidence demonstrating significant improvement in effectiveness and safety of vascular access by realtime ultrasound (US)-guidance, as compared to the anatomical landmark-guided approach. This review comments on the evidence-based recommendations on US-guided vascular access which have been published recently within the framework of Guidelines on Interventional Ultrasound (InVUS) of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) from a clinical practice point of view.

A prospective study of the value of pre- and post-treatment magnetic resonance imaging examinations for advanced cervical cancer.

BACKGROUND AND AIM: Cervical cancer has high incidence and mortality in developing countries. It is the only gynecological malignancy that is clinically staged. Staging at the time of diagnosis is crucial for treatment planning. After radiation therapy, clinical examination is limited because of radiation changes. An imaging method relatively unaffected by radiation changes would be useful for the assessment of therapy results and for management. We sought to demonstrate the value of magnetic resonance imaging (MRI) in the pre- and post-treatment assessment of cervical cancer. METHODS: This was a prospective study, carried out between November 2012 and October 2014 on 18 subjects with advanced-stage cervical cancer diagnosed by colposcopy. The disease stage was determined clinically according to the International Federation of Gynecology and Obstetrics (FIGO) criteria. Only patients with disease stage ≥ IIB or IIA with one of the tumor dimensions > 4 cm were enrolled in the study. All patients underwent abdominal-pelvic contrast-enhanced MRI as part of the workup. Tumor size, local invasion, involved pelvic lymph nodes, and staging according to MRI criteria were evaluated. Clinical and MRI examinations were also performed after chemoradiotherapy. After chemoradiotherapy, 94% of the patients (17 of 18) were treated surgically. RESULTS: Eighteen patients aged 32-67 met the inclusion criteria and were enrolled: 10 stage IIB, 6 stage IIIA, 1 stage IIA and 1 stage IIIB, according to clinical staging. Using histopathological findings as a reference, MRI staging accuracy was 83.3%. The concordance of the clinical stage with MRI stage at the first examination was 56%. Parametrial involvement was assessed on pretreatment and post-treatment MRI, with post-treatment MRI compared with histology. There was no statistically significant difference between the pre- and post-therapy gynecological examinations (GYN) and the corresponding MRI assessments as to tumor size measurements (p>0.05). The post-therapy restoration of the cervical stroma ruled out tumor recurrence. CONCLUSIONS: For a detailed characterization of loco-regional extension, the calculation of tumor volume, and the evaluation of distant metastatic changes, clinical examination is insufficient. Magnetic resonance imaging is helpful aftertherapy.

Advantages and Limitations of Focal Liver Lesion Assessment with Ultrasound Contrast Agents: Comments on the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines.

Contrast-enhanced ultrasound (CEUS) represents a significant breakthrough in sonography. Due to US contrast agents (UCAs) and contrast-specific techniques, sonography offers the potential to show enhancement of liver lesions in a similar way as contrast-enhanced cross-sectional imaging techniques. The real-time assessment of liver perfusion throughout the vascular phases, without any risk of nephrotoxicity, represents one of the major advantages that this technique offers. CEUS has led to a dramatic improvement in the diagnostic accuracy of US and subsequently has been included in current guidelines as an important step in the diagnostic workup of focal liver lesions (FLLs), resulting in a better patient management and cost-effective therapy. The purpose of this review was to provide a detailed description of contrast agents used in different cross-sectional imaging procedures for the study of FLLs, focusing on characteristics, indications and advantages of UCAs in clinical practice.

US-guided peripheral vascular interventions, comments on the EFSUMB guidelines.

Peripheral venous as well as arterial punctures have traditionally been performed on the basis of designated anatomical landmarks. However, due to patients' individual anatomy and vessel pathology and depending on individual operators' skill, this landmark approach is associated with a significant failure rate and complication risk. This review comments on the evidence-based recommendations on ultrasound (US)-guided vascular access which have been published recently within the framework of Guidelines on Interventional Ultrasound (INVUS) of the European Federation of Societies for US in Medicine and Biology (EFSUMB) from a clinical practice point of view. Part 1 of the review had its focus on general aspects of US- guidance and on central venous access, whereas part 2 refers to peripheral vascular access.

Multimodal endocavitary ultrasound versus MRI and clinical findings in pre- and post-treatment advanced cervical cancer. Preliminary report.

AIMS: The aim of this study was to evaluate the use of pre and post-therapy transrectal and transvaginal ultrasonography (TRUS, TVUS) with contrast enhancement and strain elastography compared with clinical examination and magnetic resonance imaging (MRI) in the assessment of advanced stage cervical cancer. MATERIAL AND METHODS: This was a prospective study, carried out over a period of nine months on subjects with advanced-stage cervical cancer (stage >/= IIB). All included patients were examined clinically and underwent abdomino-pelvic contrast enhanced MRI and multimodal US examinations (TRUS with strain elastography and contrast enhanced TVUS) at the time of diagnosis and after radiochemotherapy. Tumor size and staging at TRUS and TVUS was compared with the same data obtained by clinical examination and MRI. Pathology was the golden standard. RESULTS: Eight patients accomplished the inclusion criteria. In five cases the tumor stage was identical on clinical and MRI examinations. In all cases parametrial infiltration was diagnosed by all pre-treatment examinations. No significant differences were observed in tumor size between clinical, US and MRI exams either at baseline or post-therapy, in native or post-contrast examinations. The size of the tumor evaluated pre-treatment proved to be significantly smaller post-contrast in both US and MRI examinations compared with the native images. Post-therapy, no significant differences were observed on US measured tumor dimensions when comparing native with post-contrast images. Oppositely, significant smaller dimensions were observed on post-contrast MRI compared with native scans. CONCLUSIONS: TRUS is accurate in the estimation of pre-therapy cervical cancer dimension. The post therapy tumor evaluation is better performed with MRI. The use of intravenous contrast agents on both examinations did not improved the accuracy of tumor evaluation pre or post-therapy.

Transcutaneous Ultrasound: Elastographic Lymph Node Evaluation. Current Clinical Applications and Literature Review.

Distinguishing malignant versus benign lymphadenopathies is a major diagnostic dilemma in clinical medicine. Metastatic deposits in normal-sized lymph nodes (LNs) can be smaller than a millimeter, thus presenting a diagnostic challenge. In most clinical settings, however, enlarged LNs detected on imaging need to be classified as malignant or benign. Ultrasound seems to be a very reliable method for LN characterization because of the high resolution, especially in the subcutaneous areas. However, B-mode and Doppler-ultrasound criteria for characterization of a lymphadenopathy as benign or malignant are lacking specificity. Newer methods such as elastography seem to be valuable for identifying metastatic deposits within LNs and may help discriminate malignant and benign LNs. This review summarizes the different elastographic methods available and provides an overview of the relevant publications. According to the literature, elastography can be used for identifying metastatic deposits, to guide fine needle aspiration and to non-invasively choose the most suspicious LN of a group of enlarged LNs for targeted biopsy.

Villous adenoma of the common hepatic duct: the importance of contrast-enhanced ultrasound and endoscopic retrograde cholangiopancreatography for relevant diagnosis. A case report and review of the literature.

Adenomas are frequently encountered in the lower digestive tract but are rarely diagnosed in the biliary tree. We report a case of villous adenoma of the common hepatic duct. A 58-year old male was admitted with a four week history of intermittent upper right quadrant pain. Gray scale and contrast-enhanced abdominal ultrasound showed a mass inside the common hepatic duct with arterial enhancement and slow wash-out during the late venous phase. Subsequent endoscopic retrograde cholangiopancreatography and intraductal ultrasound confirmed the presence of the lesion. The final histopathological examination showed villous adenoma of the common hepatic duct with high-grade dysplasia. Contrast enhanced ultrasonography used in conjecture with endoscopic retrograde cholangiopancreatography can help in differentiating biliary tumors.

Endoscopic ultrasound elastography: Current status and future perspectives.

Elastography is a new ultrasound modality that provides images and measurements related to tissue stiffness. Endoscopic ultrasound (EUS) has played an important role in the diagnosis and management of numerous abdominal and mediastinal diseases. Elastography by means of EUS examination can assess the elasticity of tumors in the proximity of the digestive tract that are hard to reach with conventional transcutaneous ultrasound probes, such as pancreatic masses and mediastinal or abdominal lymph nodes, thus improving the diagnostic yield of the procedure. Results from previous studies have promised benefits for EUS elastography in the differential diagnosis of lymph nodes, as well as for assessing masses with pancreatic or gastrointestinal (GI) tract locations. It is important to mention that EUS elastography is not considered a modality that can replace biopsy. However, it may be a useful adjunct, improving the accuracy of EUS-fine needle aspiration biopsy (EUS-FNAB) by selecting the most suspicious area to be targeted. Even more, it may be useful for guiding further clinical management when EUS-FNAB is negative or inconclusive. In the present paper we will discuss the current knowledge of EUS elastography, including the technical aspects, along with its applications in the differential diagnosis between benign and malignant solid pancreatic masses and lymph nodes, as well as its aid in the differentiation between normal pancreatic tissues and chronic pancreatitis. Moreover, the emergent indication and future perspectives are summarized, such as the benefit of EUS elastography in EUS-guided fine needle aspiration biopsy, and its uses for characterization of lesions in liver, biliary tract, adrenal glands and GI tract.

Perihepatic lymphadenopathy in children with chronic viral hepatitis.

OBJECTIVE: To assess whether lymph node enlargement in the hepatoduodenal ligament occurs in children with chronic viral hepatitis B and C in comparison to healthy controls. SUBJECT AND METHODS: In 49 patients with chronic viral hepatitis (38 with chronic hepatitis B, 11 with chronic hepatitis C, 31 male, 18 female; age range 1 to 17 years), and in 51 healthy controls (25 male, 26 female; age range 4 to 16 years), the total perihepatic lymph node volume was assessed using transabdominal ultrasonography as previously described in adult patients. RESULTS: Adequate visualization of the liver hilum was achieved in 46/49 (94%) pediatric patients with chronic viral hepatitis and in 46/51 (90%) pediatric healthy controls. In patients with adequate liver hilum visualization, enlarged perihepatic lymph nodes (longitudinal diameter >14 mm) were detected in 32/46 (70%) patients with chronic viral hepatitis and in 5/46 (11%) healthy controls. The total perihepatic lymph nodes volume [mean ± SD] was 1.0 ± 1.2 mL (0.1-5.4 mL) in patients with chronic viral hepatitis and 0.1 ± 0.1 mL (0.0-0.4 mL) in healthy controls (p < 0.05). A maximal lymph node diameter >14 mm identified patients with chronic viral hepatitis with 70% sensitivity and 89% specificity. CONCLUSION: Transabdominal ultrasound can detect lymph nodes within the hepatoduodenal ligament not only in adults but also in children. Paediatric patients with chronic viral hepatitis have significantly enlarged perihepatic lymph nodes compared to controls. Therefore, sonographic assessment of perihepatic lymphadenopathy might be a non-invasive diagnostic tool to screen paediatric patients for chronic viral hepatitis.

Inflammatory myofibroblastic tumor of the gallbladder: imaging aspects.

Inflammatory myofibroblastic tumors (IMT) are rare benign lesions that may often be mistaken for malignancies due to their imaging resemblance. There are a limited number of case reports in the literature on the location at the level of the gallbladder. We present a case of IMT of the gallbladder that emphasizes the importance of conventional ultrasound as the primary method of detection, as well as the role of contrast-enhanced ultrasound and strain elastography in describing the lesion, thus contributing to the differential diagnosis.

Benign nodular hyperplasia of the liver-pedunculated form: diagnostic contributions of ultrasonography and consideration of exophytic liver tumors.

Focal nodular hyperplasia (FNH) is an asymptomatic benign liver tumor that may be detected accidentally during an abdominal ultrasound examination; it is associated with unspecific complaints, sometimes painful. Diagnosis can be precise using imaging techniques like ultrasonography. The diagnostic criteria are represented by the spatial display of the tumoral vessels and their hemodynamic characteristics. Sometimes differential diagnostic issues occur with other benign or malignant liver tumors. We present the case of a young female patient without a personal pathological history, who complained of intense, diffuse, intermittent, non-systematic abdominal pain and who underwent ultrasound examination, followed by contrast-enhanced ultrasound. With this technique, we evidenced a solid extrahepatic tumor, which was mobile at the patient's change of position and had the hemodynamic features of FNH. The article also tackles the problem of intra-abdominal pedunculated tumors.

Neuroendocrine tumor of gallbladder with liver and retroperitoneal metastases and a good response to the chemotherapeutical treatment.

Neuroendocrine carcinoma of the gallbladder is an uncommon disease. We present the case of a 45-year-old woman with a mass located in the gallbladder, whose diagnosis was based on contrast-enhanced ultrasound and magnetic resonance imaging. The tumor involved the liver and retroperitoneum, and was histopathologically confirmed by liver biopsy as a neuroendocrine tumor grade 3. The patient received chemotherapy with good response, followed by surgery with cholecystectomy and partial hepatectomy.

Vascular phases in imaging and their role in focal liver lesions assessment.

The incidental finding of a liver lesion with basic ultrasound is one of the most common clinical issues. Some of the liver lesions which present typical morphological B-mode features (e.g. cysts, typically localized focal fatty sparing/accumulations, hyperechoic hemangiomas) can be easily diagnosed by conventional ultrasound without the need of further diagnostic procedures. Others frequently necessitate further investigation with contrast-enhanced imaging techniques or biopsy in order to differentiate benign from malignant lesions and obtain a final diagnosis. This paper will discuss differences between vascular phases of different cross-sectional contrast-enhanced methods, as well as their subsequent benefits for focal liver lesions (FLLs) assessment, adding also a particular emphasis on small FLLs detection and characterization.

Endoscopic ultrasound: Elastographic lymph node evaluation.

Different imaging techniques can bring different information which will contribute to the final diagnosis and further management of the patients. Even from the time of Hippocrates, palpation has been used in order to detect and characterize a body mass. The so-called virtual palpation has now become a reality due to elastography, which is a recently developed technique. Elastography has already been proving its added value as a complementary imaging method, helpful to better characterize and differentiate between benign and malignant masses. The current applications of elastography in lymph nodes (LNs) assessment by endoscopic ultrasonography will be further discussed in this paper, with a review of the literature and future perspectives.

Ultrasonography of the biliary tract - up to date. The importance of correlation between imaging methods and patients' signs and symptoms.

Ultrasonography is generally accepted and performed as a first choice imaging technique in patients with jaundice. The method allows the discrimination between cholestatic and mechanical jaundice. The existing procedures are multiple: gray scale, Doppler, i.v. contrast enhancement, elastography, tridimensional ultrasonography, each of these with different contribution to the positive and differential diagnosis regarding the nature of the jaundice. The final diagnosis is a multimodal one and the efficiency is dependent on the level of the available technology, the examiner's experience, the degree and modality of integration of the data within the clinical context, as well as on the portfolio of available imaging procedures. This review shows the main ultrasonographic methods consecrated in the evaluation of the biliary tree. It also underlines the integrated character of the procedures, as well as the necessity to correlate with other imaging methods and the clinical situation.

Diffusion Weighted Magnetic Resonance Imaging for the Classification of Focal Liver Lesions as Benign or Malignant.

BACKGROUND AND AIMS: To assess the role of diffusion weighted imaging sequence (DWI), routinely used in hepatic magnetic resonance imaging (MRI) for the differentiation of focal liver lesions (FLLs) as benign or malignant. METHOD: 99 FLLs assessed by liver MRI in 80 patients were included in the present study. All lesions were retrospectively analyzed by two experienced radiologists, independent from each other, who were not aware of the previous results obtained by using different imaging techniques. All included FLLs had a final histological diagnosis or a final diagnosis based on consensus reading by two experienced radiologists and follow-up at 6 months. The FLLs signal was qualitatively appreciated on the b-800 sequences and on the apparent diffusion coefficient (ADC) map. The ADC value of each FLL was measured and the ADC ratio between the ADC value of the assessed FLL and that of the surrounding liver parenchyma were calculated. RESULTS: The mean ADC value for benign FLLs as assessed by the two independent readers was 1.78 x 10¯³ and 1.72 x 10¯³, respectively. The mean ADC value for malignant FLLs was 0.92 x 10¯³ for the first reader and 0.95 x 10¯³ for the second reader. The mean ADC ratio for benign FLLs was 1.91 and 1.85 for the two readers and for malignant FLLs was 0.91 and 0.94, respectively. Using an ADC value lower than 1.024 x 10¯³ offers a specificity of 100% and a sensitivity of 62.5% for the diagnosis of malignant FLLs. The ADC value is an indicator which is less prone to interobserver variability (correlation of 0.919→1). The ADC ratio has, as the analysis of the ROC curve shows, the best predictive value for differentiation between benign and malignant FLLs. Analysis of the signal intensity on the DWI b-800 image alone is of no significance in differentiating benign from malignant FLLs (p>0.05). CONCLUSIONS: The ADC value and the ADC ratio assessed on liver DWI are useful diagnostic tools in the differential diagnosis of benign vs. malignant FLLs. Quantitative methods such as calculating the ADC value or ADC ratio have better diagnostic value than the qualitative techniques.

Particularities of Crohn's disease in pediatric patients: current status and perspectives regarding imaging modalities.

A consensus on the best imaging modality evaluating inflammatory bowel disease in the pediatric population is lacking and it is often unclear which modality to choose in specific clinical circumstances. Children with inflammatory bowel disease are exposed to ionizing radiation from multiple imaging studies performed at initial diagnosis, throughout treatment and during the follow-up period. This paper discusses the value of different imaging techniques in pediatric patients with inflammatory bowel disease and gives a review of the literature. In addition, particular features of inflammatory bowel disease in children including the predilection of affected segments in the gastrointestinal tract are highlighted. Based on current literature knowledge, we encourage an integrative approach to the interpretation of clinical and imaging data for diagnosis and follow-up in daily clinical settings.

Benign liver tumors in pediatric patients - Review with emphasis on imaging features.

Benign hepatic tumors are commonly observed in adults, but rarely reported in children. The reasons for this remain speculative and the exact data concerning the incidence of these lesions are lacking. Benign hepatic tumors represent a diverse group of epithelial and mesenchymal tumors. In pediatric patients, most benign focal liver lesions are inborn and may grow like the rest of the body. Knowledge of pediatric liver diseases and their imaging appearances is essential in order to make an appropriate differential diagnosis. Selection of the appropriate imaging test is challenging, since it depends on a number of age-related factors. This paper will discuss the most frequently encountered benign liver tumors in children (infantile hepatic hemangioendothelioma, mesenchymal hamartoma, focal nodular hyperplasia, nodular regenerative hyperplasia, and hepatocellular adenoma), as well as a comparison to the current knowledge regarding such tumors in adult patients. The current emphasis is on imaging features, which are helpful not only for the initial diagnosis, but also for pre- and post-treatment evaluation and follow-up. In addition, future perspectives of contrast-enhanced ultrasound (CEUS) in pediatric patients are highlighted, with descriptions of enhancement patterns for each lesion being discussed. The role of advanced imaging tests such as CEUS and magnetic resonance imaging, which allow for non-invasive assessment of liver tumors, is of utmost importance in pediatric patients, especially when repeated imaging tests are needed and radiation exposure should be avoided.