The diagnostic value of Doppler Resistive Index in the differential diagnosis of focal liver lesions

Aim

To investigate the diagnostic value of resistance index (RI) in differentiating focal liver lesions.

Patients and methods

In this retrospective study, a total of 576 patients with histologically confirmed focal liver lesions were included. Each patient underwent B-mode ultrasound examination and color Doppler ultrasound examination. The RI values of different focal liver lesions were recorded and compared.

Results

The mean RI value of benign lesions was significantly lower than that of malignant lesions (0.54 ± 0.10 vs. 0.71 ± 0.12) (p <0.05). In malignant lesions, the RI value of intrahepatic cholangiocarcinoma was significantly lower than that of hepatocellular carcinoma lesions. Furthermore, in hepatocellular carcinoma lesions, the RI of large lesions (group 4: >10 cm) was significantly lower than that of small lesions (group 1: ≤2 cm, group 2: 2-5 cm) (p <0.05). Taken RI of 0.615 as a cutoff value to differentiate malignant and benign lesions, the sensitivity, specificity, positive predictive value and negative predictive value were 82.80%, 81.00%, 81.34% and 82.48%, respectively.

Conclusion

Color Doppler ultrasound examination is a valuable imaging method in detecting blood flow signal within liver lesions. The RI parameter should be helpful in differentiating malignant and benign liver tumors.

Predictive Value of Preoperative Endoscopic Ultrasound (EUS) After Neoadjuvant Chemotherapy in Locally Advanced Esophagogastric Cancer - Data From a Randomized German Phase II Trial

PURPOSE

The role of EUS before or after neoadjuvant chemotherapy (nCTX) in advanced esophagogastric cancer (EGC) is still unclear. The phase II NEOPECX trial evaluated perioperative chemotherapy with or without panitumumab in this setting. The aim of this sub-study was to investigate the prognostic value of EUS-guided preoperative staging before and after nCTX.

MATERIALS AND METHODS

Preoperative yuT/yuN stages by EUS were compared with histopathological ypT/ypN stages after curative resection. Reduction in T-stage from baseline to preoperative EUS was defined as downstaging (DS+) and compared to progression-free (PFS) and overall survival (OS) of patients without downstaging (DS-). In addition, preoperative EUS N-stages (positive N+ or negative N-) were correlated with clinical data.

RESULTS

The preoperative yuT-stage correlated with the ypT-stage in 48% of cases (sensitivity 48%, specificity 52%), while the preoperative yuN-stage correlated with the ypN-stage in 64% (sensitivity 76%, specificity 52%). Within DS+ patients who were downstaged by ≥ 2 T-categories, a trend towards improved OS was detected (median OS DS+: not reached (NR), median OS DS-: 38.5 months (M), p=0.21). Patients with yuN+ at preoperative EUS had a worse outcome than yuN- patients (median OS yuN-: NR, median OS yuN+: 38.5 M, p = 0.013).

CONCLUSION

The diagnostic accuracy of EUS to predict the response after nCTX in patients with advanced EGC is limited. In the current study the endosonographic detection of lymph node metastasis after nCTX indicates a poor prognosis. In the future, preoperative EUS with sectional imaging procedures may be used to tailor treatment for patients with advanced EGC.

Controversies in ERCP: Technical aspects

The aim of the series of papers on controversies of biliopancreatic drainage procedures is to discuss pros and cons of the varying clinical practices and techniques in ERCP and EUS for drainage of biliary and pancreatic ducts. While the first part focuses on indications, clinical and imaging prerequisites prior to ERCP, sedation options, post-ERCP pancreatitis prophylaxis, and other related technical topics, the second part discusses specific procedural ERCP techniques including precut techniques and their timing as well as management algorithms. In addition, reviews on controversies in EUS-guided bile duct and pancreatic drainage procedures are under preparation.

Controversies in ERCP: Indications and preparation

The aim of the series of papers on controversies of biliopancreatic drainage procedures is to discuss the pros and cons of the varying clinical practices and techniques in ERCP and EUS for drainage of biliary and pancreatic ducts. The first part focuses on indications, clinical and imaging prerequisites before ERCP, sedation options, post-ERCP pancreatitis (PEP) prophylaxis, and other related technical topics. In the second part, specific procedural ERCP-techniques including precut techniques and its timing as well as management algorithms are discussed. In addition, controversies in EUS-guided bile duct and pancreatic drainage procedures are under preparation.

EFSUMB 2020 Proposal for a Contrast-Enhanced Ultrasound-Adapted Bosniak Cyst Categorization - Position Statement

The well-established Bosniak renal cyst classification is based on contrast-enhanced computed tomography determining the malignant potential of cystic renal lesions. Ultrasound has not been incorporated into this pathway. However, the development of ultrasound contrast agents coupled with the superior resolution of ultrasound makes it possible to redefine the imaging of cystic renal lesions. In this position statement, an EFSUMB Expert Task Force reviews, analyzes, and describes the accumulated knowledge and limitations and presents the current position on the use of ultrasound contrast agents in the evaluation of cystic renal lesions.

[Spleen biopsy: "pros and cons" or better "when and when not?"]

Due to the relatively high complication rate, the necessity of a spleen biopsy is controversially discussed. In establishing its indication, the clinical background and performed diagnostics must be considered. Based on the medical history, imaging procedures and sonographic course, different clinical scenarios are conceivable. The aim of this review is to describe the indications of splenic biopsy considering various clinical scenarios.

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.

EchoScopy in scanning abdominal diseases; a prospective single center study

BACKGROUND AND AIMS

The introduction of a new type of small handheld ultrasound device brings greater portability and affordability in a different setting. The basic ultrasound approach with these handheld devices has been defined by European Federation of Societies of Ultrasound in Medicine and Biology (EFSUMB) as "EchoScopy". The current study aimed to assess the image quality, indications and limitations of a portable pocket "EchoScopy" performed first compared with a high-end ultrasound system (second) in abdominal diseases.

MATERIAL AND METHODS

Three hundred consecutive patients (158 males and 142 females, age 55±19 [18-96]) years) were included. The ultrasound examinations were performed firstly by an EchoScope (Vscan™ Dual Probe) and secondly with a high-end ultrasound system (HEUS, GE Logiq E9). Compared with the always excellent image quality using HEUS, the image quality of the EchoScope was graded as good, sufficient or non-sufficient.

RESULTS

Out of all 300 patients, 221 had focal lesions, 31 patients were found with diffuse pathological findings, 20 with ascites, 25 after liver puncture and 45 without any pathological findings. The image quality of the pocket device was considered as being good or sufficient to delineate the pathology in 265/300 (88%). The detection rate of the EchoScope for abdominal focal lesion was 172/221 (78%). The higher frequency of the Dual Probe was helpful in 35/300 (12%).

CONCLUSIONS

EchoScopy has proven to display sufficient image quality to answer specific questions, e.g., detection of ascites, splenomegaly, bile duct enlargement, hydronephrosis and other pathological findings which can be judged by "yes/no".

Changes in tumor vascularity depicted by contrast-enhanced EUS as a predictor of prognosis and treatment efficacy in patients with unresectable pancreatic cancer (PEACE): A study protocol

Patients with unresectable pancreatic cancer have a poor prognosis. The analysis of prognostic factors before treatment may be helpful in determining the best therapeutic strategies. The aim of the PEACE study is to assess the vascularity of pancreatic malignant tumors using contrast-enhanced harmonic EUS (CEH-EUS) and to clarify the prognostic value of tumor vascularity in patients with locally advanced and metastatic pancreatic cancer. Hereby, we present the protocol of a prospective, nonrandomized, single-arm, multicenter study aiming to assess changes in tumor vascularity using CEH-EUS before and 2 months after treatment initiation in patients with unresectable, locally advanced/metastatic pancreatic cancer and to examine the correlation between vascular changes and treatment response, progression-free survival, and overall survival.

Endoscopic ultrasound elastography of small solid pancreatic lesions: a multicenter study

BACKGROUND

The prevalence of malignancy in patients with small solid pancreatic lesions is low; however, early diagnosis is crucial for successful treatment of these cases. Therefore, a method to reliably distinguish between benign and malignant small solid pancreatic lesions would be highly desirable. We investigated the role of endoscopic ultrasound (EUS) elastography in this setting.

METHODS

Patients with solid pancreatic lesions ≤ 15 mm in size and a definite diagnosis were included. Lesion stiffness relative to the surrounding pancreatic parenchyma, as qualitatively assessed and documented at the time of EUS elastography, was retrospectively compared with the final diagnosis obtained by fine-needle aspiration/biopsy or surgical resection.

RESULTS

218 patients were analyzed. The average size of the lesions was 11 ± 3 mm; 23 % were ductal adenocarcinoma, 52 % neuroendocrine tumors, 8 % metastases, and 17 % other entities; 66 % of the lesions were benign. On elastography, 50 % of lesions were stiffer than the surrounding pancreatic parenchyma (stiff lesions) and 50 % were less stiff or of similar stiffness (soft lesions). High stiffness of the lesion had a sensitivity of 84 % (95 % confidence interval 73 % - 91 %), specificity of 67 % (58 % - 74 %), positive predictive value (PPV) of 56 % (50 % - 62 %), and negative predictive value (NPV) of 89 % (83 % - 93 %) for the diagnosis of malignancy. For the diagnosis of pancreatic ductal adenocarcinoma, the sensitivity, specificity, PPV, and NPV were 96 % (87 % - 100 %), 64 % (56 % - 71 %), 45 % (40 % - 50 %), and 98 % (93 % - 100 %), respectively.

CONCLUSIONS

In patients with small solid pancreatic lesions, EUS elastography can rule out malignancy with a high level of certainty if the lesion appears soft. A stiff lesion can be either benign or malignant.

Standardisierte Befundung und Dokumentation der Kontrastmittelsonografie der Leber (CEUS LI-RADS)

In der Abklärung von hepatozellulären Karzinomen (HCCs) bei Hochrisikopatienten wurde zur standardisierten Befundung und Dokumentation der Kontrastmittel-Computertomografie (CECT) und Kontrastmittel-Magnetresonanztomografie (CEMRT) vor wenigen Jahren das „Liver Imaging Reporting and Data System” (LI-RADS) durch das American College of Radiology (ACR) erstellt. Die LI-RADS-Kategorisierung wird zur Klassifikation von Leberläsionen in der Leberzirrhose als sicher benigne (LR-1), intermediär (LR2 – 4) bis zu „definitiv HCC“ (LR-5) beurteilt. Seit 2014 wurde die LI-RADS-Klassifikation durch eine Arbeitsgruppe von internationalen Radiologen und Hepatologen auf die Kontrastmittelsonografie erweitert. Zeitgleich mit der Zulassung des Kontrastmittels SonoVue™ (in den USA Lumason™) wurde die Klassifikation 2016 in die LI-RADS Kategorisierung integriert und wird in diesem Artikel erläutert (CEUS-LI-RADS).

Statement and Recommendations on Interventional Ultrasound as a Thyroid Diagnostic and Treatment Procedure

The recently published guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) on interventional ultrasound (INVUS)-guided procedures summarize the intended interdisciplinary and multiprofessional approach. Herewith, we report on recommendations for interventional procedures for diagnosis and treatment of the thyroid gland.

How to perform Contrast-Enhanced Ultrasound (CEUS)

"How to perform contrast-enhanced ultrasound (CEUS)" provides general advice on the use of ultrasound contrast agents (UCAs) for clinical decision-making and reviews technical parameters for optimal CEUS performance. CEUS techniques vary between centers, therefore, experts from EFSUMB, WFUMB and from the CEUS LI-RADS working group created a discussion forum to standardize the CEUS examination technique according to published evidence and best personal experience. The goal is to standardise the use and administration of UCAs to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.

Autoimmune pancreatitis: Imaging features

Background and Objectives

Autoimmune pancreatitis (AIP) remains a difficult disease to diagnose before treatment, particularly if presenting as a focal mass lesion. The purpose of this multicenter retrospective study is to analyze imaging features of histologically confirmed AIP to determine the additional diagnostic value of contrast-enhanced ultrasound (CEUS), contrast-enhanced endoscopic ultrasound (CE-EUS), and elastography to B-mode features.

Patients and Methods

We report on a retrospective data collection of 60 histologically confirmed cases of AIP in comparison to 16 patients with pancreatic adenocarcinomas (PDAC). All CE (-E) US examinations were assessed by two independent readers in consensus. The role of CEUS and CE-EUS for pancreatic evaluation was defined according to the 2011 European Federation of Societies for Ultrasound in Medicine and Biology guidelines.

Results

After injection of ultrasound (US) contrast agents, most AIP lesions displayed focal or diffuse isoenhancement (86.6%) in the arterial phase, while most of the PDAC lesions (93.7%) were hypoenhancing (P < 0.01). During the late phase, most AIP lesions were hyper-(65%) or iso-enhancing (35%), while most PDAC lesions were hypoenhancing (93.7%). CE-EUS was performed in a subset of ten patients and showed hyperenhancement in all AIP cases. Most focal AIP lesions (n = 27, 79.4%) were stiffer than the surrounding pancreatic parenchyma.

Conclusions

In this study, percutaneous and endoscopic contrast enhanced harmonic US techniques consistently revealed diffuse and focal types of AIP to have features consistent with vascularized lesions. Differentiation from the typically hypovascularized pancreatic adenocarcinoma was possible with CE (-E) US evaluation.

[Ultrasound in palliative care medicine, Part II]

Complementary to part 1, this review summarizes indications, opportunities and applications of ultrasounds in palliative care medicine. In particular, the following topics are discussed: · Ultrasound as a non-invasive, low-threshold, bedside technique, which uniquely combines diagnostic efficacy and empathy.. · Sonographic surveillance of patients with malignant disease.. · Point-of-care application of ultrasound in palliative care services.. · Ultrasound-guided palliative interventions (drainage of effusions and other therapeutic procedures)..

Contrast enhanced ultrasound features of hepatic cystadenoma and hepatic cystadenocarcinoma

OBJECTIVE

Hepatic (biliary) cystic tumor (HBCT) is a rare focal cystic liver lesion, which has been rarely described in the literature. In our current multicenter, retrospective study, we aimed to analyze contrast enhanced ultrasound (CEUS) features and its diagnostic performance in histologically proved HBCT.

MATERIAL AND METHODS

Twenty-three patients with single HBCT were retrospectively analyzed. Histologically, 17 (73.9%) were benign hepatic (biliary) cystadenoma (HBCA), 6 (26.1%) were hepatic (biliary) cystadenocarcinoma (HBCAC). All CEUS examinations were assessed by two independent radiologists in consensus. Criteria of CEUS imaging evaluation included the contrast enhancement pattern of lesion (hypoenhancing, hyperenhancing, isoenhancing in comparison to the surrounding liver parenchyma) during the arterial, portal venous and late phases.

RESULTS

After injection of ultrasound contrast agents, most of the HBCTs (78.3%, 18/23) had typical honeycomb enhancement pattern of the cystic wall, septa or mural nodules. Comparing between HBCA and HBCAC, hyperenhancement of the honeycomb septa during the arterial phase was more common in HBCA (p = .047). However, hypoenhancement during the portal venous and late phases was the characteristic of HBCAC (p = .041).

CONCLUSIONS

The EFSUMB algorithm for CEUS for characterization of solid focal liver lesions is also applicable to HBCT. CEUS evaluation can avoid further diagnostic investigations or invasive biopsy procedure.

Contrast-enhanced (endoscopic) ultrasound and endoscopic ultrasound elastography in gastrointestinal stromal tumors

Background and Objectives:

Gastrointestinal stromal tumors (GISTs) represent the largest group of subepithelial tumors (SET) of the upper gastrointestinal (GI) tract. They may show malignant behavior, in contrast to other SET. Endoscopic ultrasound (EUS) is frequently used to characterize SET. With the introduction of contrast-enhanced ultrasound (CEUS) into EUS (CE-EUS), distinct enhancement patterns can be detected. In the presented study, the characteristic features of CE-EUS in GIST are analyzed and compared with those of other SET.

Materials and Methods:

Consecutive patients from four centers with SET of the upper and middle GI tract were included and received endoscopic or transcutaneous CEUS. The results were compared with EUS-guided tissue acquisition, forceps biopsy, or surgical resection.

Results:

Forty-two out of 62 (68%) patients had SET of the stomach, 17/62 (27%) of the small intestine, 2/62 (3%) of the esophagus, and 1/62 (2%) extraintestinal. Eighty-one percent underwent surgery. Leiomyoma was found in 5/62 (8%) and GIST in 57/62 patients (92%). Thirty-nine out of 57 (68%) patients had GIST lesions in the stomach, 17/57 (30%) had GIST of the small intestine, and 1/57 (2%) patients had extraintestinal GISTs. GIST size was 62.6 ± 42.1 (16–200) mm. Hyperenhancement had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 98%, 100%, 100%, 93%, and 98% for the diagnosis of GIST. Fifty out of 57 patients with GIST (88%) showed avascular areas in the center of the lesions.

Conclusion:

CE-EUS and CEUS show hyperenhancement and avascular areas in a high percentage of GIST but not in leiomyoma. Thus, GIST and leiomyoma can be discriminated accurately.

B-mode and contrast-enhancement characteristics of small nonincidental neuroendocrine pancreatic tumors

BACKGROUND AND OBJECTIVES

Imaging of the pancreas for detection of neuroendocrine tumors is indicated as surveillance in multiple endocrine neoplasia type 1 (MEN1) or if typical clinical symptoms combined with hormone production raise the suspicion of a neuroendocrine tumor. Endoscopic ultrasound (EUS) is considered the best imaging modality to detect small pancreatic tumors. However, little is known about how small pancreatic neuroendocrine tumors (pNETs) present on EUS.

PATIENTS AND METHODS

In this multicenter study, we retrospectively analyzed the endosonographic characteristics of small pNETs which had been detected due to typical biochemistry and clinical symptoms or during surveillance of MEN 1. Only small pancreatic tumors ≤15 mm with histological confirmation as pNET were included. B-mode and contrast-enhanced ultrasound- and EUS patterns were analyzed.

RESULTS

Among 32 patients with histologically proven small pNETs, 7 patients had known MEN1. Among the pNETs, 20 were insulinoma, 2 gastrinoma, 3 glucagonoma, 6 nonfunctional in MEN1, and one PPoma. 94% of the pNET appeared hypoechogenic, only 1 isoechogenic and 1 hyperechogenic. After contrast injection, 90% of the pNETS showed hyperenhancement compared to the surrounding pancreatic parenchyma.

CONCLUSION

The high spatial resolution of EUS allows detection and even cytological confirmation of pNET <7 mm diameter. Hypoechogenicity in B-mode and hyperenhancement after injection of contrast agents are endosonographic characteristics of small pNET and present in >90% of pNETs.

Endorectal fusion imaging: A description of a new technique

BACKGROUND

Fusion imaging is an accepted method in abdominal imaging allowing a simultaneous display of reference imaging with a live ultrasound (US) investigation. For prostate cancer, promising results have been published for endorectal US (ERUS)-guided biopsy of suspicious lesions in magnetic resonance imaging (MRI). To our knowledge, no other indication for the fusion of ERUS with MRI has been reported so far.

METHODS

We report on three patients scheduled for ERUS due to anorectal fistulae after treatment (n = 2) or rectal carcinoma (n = 1), which were scheduled for real-time virtual onography (RVS), a method for the fusion of MRI imaging with US.

RESULTS

In all patients, RVS was successful. The course of the fistulae could be defined and the success of the treatment could be confirmed. In the patient with rectal carcinoma, the lymph nodes suspicious in MRI could be identified.

CONCLUSIONS

MRI/ERUS fusion has the potential for follow-up of anorectal fistulae and abscesses, and staging of anal and rectal tumors.

Role of contrast-enhanced endoscopic ultrasound in lymph nodes

Diagnosing unclear lymph node (LN) enlargements in the mediastinum and abdomen is the most important indication of endoscopic ultrasound (EUS)-fine needle aspiration (FNA) after the diagnosis and treatment of pancreatic diseases. Investigating LNs in these areas can happen in different clinical settings. Mostly, it is the first modality in general LN diseases without any peripheral LN enlargements. On the other hand, it can be the question of LN involvement in a known or suspected primary tumor. Due to EUS-FNA cytology, those questions can be answered highly, accurately. However, a primary discrimination of LNs might be helpful to increase the diagnostic value of the FNA cytology, especially in cases with multiple LN enlargements and hard to reach enlarged LNs for example by vessel interposition. Because of the unreliability of B-mode criteria, further diagnostic improvements such as elastography and contrast-enhanced EUS are investigated to increase the accuracy of the initial diagnosis.

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part VI - Ultrasound-Guided Vascular Interventions

The sixth part of the Guidelines on Interventional Ultrasound produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) assesses the evidence for ultrasound guidance and assistance in vascular interventions. Based on convincing data, real-time sonographic guidance for central venous access is strongly recommended as a key safety measure. Systematic analysis of scientific literature shows that in difficult situations and special circumstances US guidance may also improve the efficacy and safety of peripheral venous and arterial access and endovascular interventions. Moreover, the recommendations of this guideline endorse the use of ultrasound to detect complications of vascular access and US-guided interventional treatment of arterial pseudoaneurysms.

Comments and extensions to EFSUMB guidelines on renal interventional ultrasound (INVUS)

The substantial evidence base for interventional ultrasound approaches to renal diagnostic sampling and therapeutic access exists. This review comments on the evidence-based recommendations on ultrasound-guided renal 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. Specific aspects of tissue handling and workup, procedural approach and patient interaction are discussed. Indications, contraindications, risk factors and methods to reduce these risks are considered.

Feasibility and Usefulness of Intra-Cavitary Contrast-Enhanced Ultrasound in Percutaneous Nephrostomy

The aim of this study was to evaluate the feasibility and utility of intra-cavitary contrast enhanced ultrasound (ICCEUS) in guiding percutaneous nephrostomy (PCN) and assessing complications. Forty-five ultrasound-guided PCNs were performed in 35 patients with hydronephrosis resulting from urinary tract obstruction. Ultrasound contrast agent (0.1 mL diluted in 20-30 mL saline) was injected through the puncture needle and the drainage tube to precisely locate the device and obstruction, with the fluoroscopy results considered the gold standard. ICCEUS was performed again the next day to assess complications. All 45 PCNs were successfully performed under the guidance of ultrasound. With ICCEUS, we could confirm the correct insertion of needle and catheter and locate the obstruction in all 35 patients, with fluoroscopic results as the gold standard. Catheter dislodgement was diagnosed by administration of ultrasound contrast agent in 5 patients. Hematoma (1 patient) and urine leakage (1 patient) were also observed. With the advantages of lack of exposure to radiation, performance in real time and bedside availability, ICCEUS has the potential to become a new modality to guide PCN and assess catheter-related complications.

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part V - EUS-Guided Therapeutic Interventions (short version)

The fifth section of the Guidelines on Interventional Ultrasound (INVUS) of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) assesses the evidence for all the categories of endoscopic ultrasound-guided treatment reported to date. Celiac plexus neurolysis and block, vascular intervention, drainage of fluid collections, drainage of biliary and pancreatic ducts, and experimental tumor ablation techniques are discussed. For each topic, all current evidence has been extensively analyzed and summarized into major recommendations for reader consultation (short version; the long version is published online).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part V

The fifth section of the Guidelines on Interventional Ultrasound (INVUS) of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) assesses the evidence for all the categories of endoscopic ultrasound-guided treatment reported to date. Celiac plexus neurolysis and block, vascular intervention, drainage of fluid collections, drainage of biliary and pancreatic ducts, and experimental tumor ablation techniques are discussed. For each topic, all current evidence has been extensively analyzed and summarized into major recommendations for reader consultation in clinical practice (long version).

Contrast-enhanced ultrasound of histologically proven hepatic epithelioid hemangioendothelioma

AIM: To analyze contrast-enhanced ultrasound (CEUS) features of histologically proven hepatic epithelioid hemangioendothelioma (HEHE) in comparison to other multilocular benign focal liver lesions (FLL).

METHODS: Twenty-five patients with histologically proven HEHE and 45 patients with histologically proven multilocular benign FLL were retrospectively reviewed. Four radiologists assessed the CEUS enhancement pattern in consensus.

RESULTS: HEHE manifested as a single (n = 3) or multinodular (n = 22) FLL. On CEUS, HEHE showed rim-like (18/25, 72%) or heterogeneous hyperenhancement (7/25, 28%) in the arterial phase and hypoenhancement (25/25, 100%) in the portal venous and late phases (PVLP), a sign of malignancy. Eighteen patients showed central unenhanced areas (18/25, 72%); in seven patients (7/25, 28%), more lesions were detected in the PVLP. In contrast, all patients with hemangioma and focal nodular hyperplasia showed hyperenhancement as the most distinctive feature (P < 0.01).

CONCLUSION: CEUS allows for characterization of unequivocal FLL. By analyzing the hypoenhancement in the PVLP, CEUS can determine the malignant nature of HEHE.

Duplex sonography of the mesenteric vessels--a critical evaluation of inter-observer variability

INTRODUCTION

The number of publications concerning mesenteric Doppler sonography (mesDS) is immense and does not correlate with the frequency of its use in clinical practice. This is astonishing since it provides real time blood flow (perfusion) information without side effects. Despite uncontrollable parameters like the technical limitations in some situations the optimization of (possibly) controllable parameters like standardization, production of normal values and reduction of the investigator variability by evaluating stable parameters could change the situation.

PATIENTS AND METHODS

10 investigators experienced in abdominal sonography ("DEGUM-Seminarleiter") performed mesenteric Doppler sonography in 5 healthy subjects with 5 different machines.

RESULTS

The portal vein at the confluence and the common hepatic artery provide a significant portion of investigations with intromission angles of more than 60°. Values of diameter, resistance index and pulsatility index of the celiac trunc could be obtained with inter-observer variability values below 25 %. The proper and the common hepatic artery show no differences in inter-observer variability values, whereas the intrahepatic measure point of the portal vein showed a higher reproducibility.

DISCUSSION

We define frame conditions for future mesenteric Doppler studies: the portal vein should be investigated at the intrahepatic measure point. Pathophysiological studies should refrain from velocity parameters except in the case of larger vessels running in a straight course towards the probe.

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part IV - EUS-guided Interventions: General aspects and EUS-guided sampling (Long Version)

The fourth part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound describes general aspects of endoscopic ultrasound-guided diagnostic and therapeutic interventions and assesses the evidence for endoscopic ultrasound-guided sampling. Endoscopic ultrasound combines the most advanced high-resolution ultrasound imaging of lesions within the wall and in the vicinity of the gastrointestinal tract and safe and effective fine needle based tissue acquisition from these lesions. The guideline addresses the indications, contraindications, techniques, adverse events, training and clinical impact of EUS-guided sampling. Advantages and drawbacks are weighed in comparison with image-guided percutaneous biopsy. Based on the most current evidence, clinical practice recommendations are given for crucial preconditions and steps of EUS-guided sampling as well as for safe performance. Additionally, the guideline deals with the principles and reliability of cytopathological reporting in endoscopic ultrasound-guided sampling (long version).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part IV - EUS-guided interventions: General Aspects and EUS-guided Sampling (Short Version)

The fourth part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound describes general aspects of endoscopic ultrasound-guided diagnostic and therapeutic interventions and assesses the evidence for endoscopic ultrasound-guided sampling. Endoscopic ultrasound combines the most advanced high-resolution ultrasound imaging of lesions within the wall and in the vicinity of the gastrointestinal tract and safe and effective fine needle-based tissue acquisition from these lesions. The guideline addresses the indications, contraindications, techniques, adverse events, training and clinical impact of EUS-guided sampling. Advantages and drawbacks are weighed in comparison with image-guided percutaneous biopsy. Based on the most current evidence, clinical practice recommendations are given for crucial preconditions and steps of EUS-guided sampling as well as for safe performance. Additionally, the guideline deals with the principles and reliability of cytopathological reporting in endoscopic ultrasound-guided sampling (short version; the long version is published online).

Percutaneous sclerotherapy of liver and renal cysts, comments on the EFSUMB guidelines

Cystic lesions in the liver and kidneys are common incidental findings. They are generally benign and require no treatment. They can appear sporadically or as part of a syndrome, and are characterised by their anechoic structure and posterior enhancement in ultrasound imaging. Increased size, haemorrhage or infection of a cyst can lead to development of symptoms. Along with surgical options and laparoscopic cyst fenestration, ultrasound-guided sclerotherapy of symptomatic cysts represents an effective and safe minimally invasive treatment option.

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part III - Abdominal Treatment Procedures (Long Version)

The third part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound (INVUS) assesses the evidence for ultrasound-guided and assisted interventions in abdominal treatment procedures. Recommendations for clinical practice are presented covering indications, contraindications, and safe and effective performance of the broad variety of these techniques. In particular, drainage of abscesses and fluid collections, interventional tumor ablation techniques, interventional treatment of symptomatic cysts and echinococcosis, percutaneous transhepatic cholangiography and drainage, percutaneous gastrostomy, urinary bladder drainage, and nephrostomy are addressed (long version).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part III - Abdominal Treatment Procedures (Short Version)

The third part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound assesses the evidence for ultrasound-guided and assisted interventions in abdominal treatment procedures. Recommendations for clinical practice are presented covering indications, contraindications, safety and efficacy of the broad variety of these techniques. In particular, drainage of abscesses and fluid collections, interventional tumor ablation techniques, interventional treatment of symptomatic cysts and echinococcosis, percutaneous transhepatic cholangiography and drainage, percutaneous gastrostomy, urinary bladder drainage, and nephrostomy are addressed (short version; a long version is published online).

Intracavitary contrast-enhanced ultrasound in abscess drainage--feasibility and clinical value

OBJECTIVE

To evaluate the usefulness of intracavitary-applied contrast-enhanced ultrasound (ICCEUS) with BR1 in ultrasound-guided puncture and drainage of abdominal and pelvic abscesses.

MATERIAL AND METHODS

A total of 71 consecutive patients received ICCEUS after placement of a drainage catheter or a needle in abdominal or pelvic abscesses. Portions of 0.1 ml of BR1 and 20 ml of saline were injected through the drainage catheter or needle. Ultrasound recordings were evaluated to answer the following questions: correct placement of the catheter by showing enhancement in the cavity and the drain - ICCEUS findings suggesting incomplete enhancement in all abscess cavities - enhancement in non-abscess structures.

RESULTS

About 52% of patients had liver, 14% of patients had intraperitoneal, 11% had subphrenic, 14% had retroperitoneal, 6% had splenic, and 4% had pelvic abscesses. The majority of the patients received drain placement with 10-F using trocar technique. Enhancement in the drain or needle was seen in all patients. In 2% of patients, during the initial approach, a dislodgment of the catheter from the abscess cavity was diagnosed. Due to non-enhancing abscess compartments, in 36% of the patients more than one drainage treatment was necessary at the time of the first approach. In 14% of the patients communication with surrounding structures was diagnosed. Additional treatment resulted in 4% of cases.

CONCLUSION

ICCEUS was helpful in all patients to confirm correct placement of drain or puncture needle. In 40% of patients, as a consequence of ICCEUS, additional therapy was scheduled, either additional drainage or abscess puncture, endoscopic retrograde drainage of the biliary or pancreatic duct or thoracic intervention.

Ultrasound contrast agents

Endoscopic ultrasound (EUS) plays an important role in imaging of the mediastinum and abdominal organs. Since the introduction of US contrast agents (UCA) for transabdominal US, attempts have been made to apply contrast-enhanced US techniques also to EUS. Since 2003, specific contrast-enhanced imaging was possible using EUS. Important studies have been published regarding contrast-enhanced EUS and the characterization of focal pancreatic lesions, lymph nodes, and subepithelial tumors. In this manuscript, we describe the relevant UCA, their application, and specific image acquisition as well as the principles of image tissue characterization using contrast-enhanced EUS. Safety issues, potential future developments, and EUS-specific issues are reviewed.

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.

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part II. Diagnostic Ultrasound-Guided Interventional Procedures (Long Version)

This is the second part of the series on interventional ultrasound guidelines of the Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). It deals with the diagnostic interventional procedure. General points are discussed which are pertinent to all patients, followed by organ-specific imaging that will allow the correct pathway and planning for the interventional procedure. This will allow for the appropriate imaging workup for each individual interventional procedure (Long version).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part II. Diagnostic Ultrasound-Guided Interventional Procedures (Short Version)

This is the second part of the series on interventional ultrasound guidelines of the Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). It deals with the diagnostic interventional procedure. General points are discussed which are pertinent to all patients, followed by organ-specific imaging that will allow the correct pathway and planning for the interventional procedure. This will allow for the appropriate imaging workup for each individual interventional procedure (Long version/ short version; the long version is published online).

Intestinal Ultrasound in Rare Gastrointestinal Diseases, Update, Part 2

Intestinal ultrasound has become an established and valid diagnostic method for inflammatory bowel disease, diverticulitis, appendicitis, bowel obstruction, perforation and intussusception. However, little is known about sonographic findings in other rarer intestinal diseases. Ultrasound may display the transformation of the intestinal wall from a normal to a pathological state both in inflammatory and neoplastic disease. Besides demonstrating the transmural aspect, it also shows the mesenteric reaction as well as complications such as fistula, abscesses, stenosis, or ileus. Furthermore, in some diseases intestinal ultrasound may serve as a diagnostic clue if typical patterns of the bowel wall and impaired peristalsis can be demonstrated. This may lead to an important reduction of invasive and expensive (follow-up) procedures. The information gained by ultrasound regarding intestinal disease, however, is as important and valid as e. g. in case of focal lesions of the liver. Serving as tertiary referral centers for a broad spectrum of intestinal diseases, we therefore report some aspects of ultrasound in patients with less often recognized diseases. The article is divided into two parts, the first focusing on examination techniques, infectious diseases and celiac sprue and the second on hereditary, vascular and neoplastic diseases and varia.

Percutaneous biopsies of splenic lesions--a clinical and contrast enhanced ultrasound based algorithm

OBJECTIVE

Splenic lesions are rare and characterization is difficult. Secondary spread is more frequent than primary malignant lesions. Thus clinical circumstances are important in the general work-up. Contrast enhanced ultrasound (CEUS) had high accuracy in recent studies but the positive predictive value is low. Biopsy is considered dangerous. Recent studies have brought back this method into focus showing an excellent efficacy and safety. The aim of this study was to estimate the rate of relevant biopsy results in patients with splenic lesions concerning the clinical circumstances.

DESIGN

Patients with unclear splenic lesions which appeared progressively hypoenhancing in the late phase of CEUS with BR1 were included. Biopsy was performed with ultrasound guidance. Patients were sorted into 5 groups according to their clinical symptoms.

RESULTS

44 patients were enrolled, 59% had benign lesions. 73% were rated relevant. For the subgroups the rate was: patients with hints for hemato-oncological diseases 83%, patients without symptoms 38%, patients with infections of unknown origin 100%, patients with suspicion of metastases 33%, immunocompromised patients 100%. One bleeding could be managed conservatively, another bleeding was detected incidentally 2 weeks later.

CONCLUSION

Percutaneous biopsy of unclear splenic lesions which appear hypoenhancing in the late phase of CEUS with BR1 results in a high rate of relevant lesions. The results should be tested in larger numbers of patients.

Quantitative contrast-enhanced harmonic EUS in differential diagnosis of focal pancreatic masses (with videos)

BACKGROUND

The role of EUS with contrast agents can be expanded through the use of time-intensity curve (TIC) analysis and computer-aided interpretation.

OBJECTIVE

To validate the use of parameters derived from TIC analysis in an artificial neural network (ANN) classification model designed to diagnose pancreatic carcinoma (PC) and chronic pancreatitis (CP).

SETTING

Prospective, multicenter, observational trial-endoscopy units from Romania, Denmark, Germany, and Spain.

PATIENTS

A total of 167 consecutive patients with PC or CP.

INTERVENTIONS

Contrast-enhanced harmonic EUS (CEH-EUS) and EUS-guided FNA (EUS-FNA), TIC analysis, and ANN processing.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, positive and negative predictive values (PPV, NPV) for EUS-FNA, CEH-EUS, and the ANN.

RESULTS

After excluding all of the recordings that did not meet the technical and procedural criteria, 112 cases of PC and 55 cases of CP were included. EUS-FNA was performed in 129 patients, and the diagnosis was confirmed by surgery (n = 15) or follow-up (n = 23) in the remaining cases. Its sensitivity and specificity were 84.82% and 100%, respectively, whereas the PPV and NPV were 100% and 76.63%, respectively. The sensitivity of real-time quantitative assessment of CEH-EUS was 87.5%, specificity 92.72%, PPV 96.07%, and NPV 78.46%. Peak enhancement, wash-in area under the curve, wash-in rate, and the wash-in perfusion index were significantly different between the groups. No significant differences were found between rise time, mean transit time, and time to peak. For the ANN, sensitivity was 94.64%, specificity 94.44%, PPV 97.24%, and NPV 89.47%.

LIMITATIONS

Only PC and CP lesions were included.

CONCLUSION

Parameters obtained through TIC analysis can differentiate between PC and CP cases and can be used in an automated computer-aided diagnostic system with good diagnostic results. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01315548.).

Local ablative procedures of the liver

Local ablative therapies have become an important part in the portfolio of treatment for patients with malignant tumors especially in the liver. Although percutaneous ethanol injection still plays a role, current guidelines favor radiofrequency ablation with a higher efficacy for complete tumor destruction. Nevertheless transplantation and surgical resection remain the gold standard due to their superiority in local control and improved survival. In this manuscript we discuss the technique in detail.

Percutaneous transhepatic cholangiography and drainage using extravascular contrast enhanced ultrasound

BACKGROUND AND PURPOSE

Percutaneous transhepatic cholangiography and drainage (PTCD) is a common procedure for the diagnosis and treatment of benign and malignant biliary diseases. Ultrasound (US) is frequently used for the guidance of PTCD. Conventional fluoroscopy is applied to evaluate the biliary system, but delivers significant X-ray dosage to the patient and the interventional team. The purpose of this study is to test the ability of extravascular contrast-enhanced ultrasound (EV-CEUS) in US-guided PTCD to reduce or replace fluoroscopy.

PATIENTS AND METHODS

38 patients underwent PTCD. 2 - 4 mL doses of a SonoVue dilution were repeatedly injected to demonstrate correct needle and drainage positions in the biliary system and in the intestine during the intervention and during follow-up to screen for complications. The results were compared to those of conventional radiography.

RESULTS

The success rate for cholangiography was 100 % for EV-CEUS and fluoroscopy each. 27/38 patients (71 %) received a ring catheter, 5/38 patients (13 %) received a metal stent. Only external drainage was possible in 6/38 patients (16 %) in the first session. In 50 % of them (3/38, 8 %) internalization was possible in the second attempt. With EV-CEUS the level of obstruction could be correctly diagnosed in 100 % of the patients. The degree of obstruction (complete/incomplete) could be correctly diagnosed in 37/38 patients (97 %). EV-CEUS was not able to demonstrate the guide wire. In 1/38 patient a hematoma appeared which was managed conservatively. Dislodgement was diagnosed in 2/38 (5 %) patients during follow-up by injecting EV-CEUS solution into the drain. Pleural injury with fistula could be demonstrated in 1/38 (3 %) patients.

CONCLUSION

EV-CEUS can monitor the success of insertion of needle and catheter, demonstrate or exclude complications, and therefore significantly reduce fluoroscopy time in US-guided PTCD. Fluoroscopy is needed whenever subtle wire steering is necessary as in most cases when the intestinal position of the drain is sought. If only external drainage is necessary fluoroscopy can be omitted.

[Ultrasound in palliative care medicine]

This review summarizes ultrasound guided interventions in palliative care medicine.

Feasibility and usefulness of using swallow contrast-enhanced ultrasound to diagnose Zenker's diverticulum: preliminary results

Zenker's diverticulum (ZD) may be misdiagnosed on conventional ultrasound as a thyroid nodule or other lesion. A barium esophagram is usually used to confirm the diagnosis; however, this procedure exposes the patient to radiation. The aim of this study was to evaluate the feasibility of using swallow contrast-enhanced ultrasound (swallow-CEUS) to diagnose ZD. Ten consecutive patients with ZD (7 men and 3 women, aged 67 ± 11 y) were included in the study. In 4 patients, ZD was incidentally found on head and neck ultrasound, and in 6 patients, ZD was suspected because of dysphagia. All lesions could be detected on conventional ultrasound before swallow-CEUS. Ten healthy volunteers (8 men and 2 women, aged 60 ± 12 y) were chosen as a control group. Written informed consent was obtained. With the patient in the sitting or upright position, conventional ultrasound was performed first to image the lesion, then the patient was asked to swallow ultrasound contrast agent (UCA) (2-4 drops of SonoVue diluted with about 200 mL of tap water). Transity of the contrast agent in the esophagus was imaged with CEUS. Retention of the UCA in the diverticulum was monitored for at least 3 min. All patients underwent a barium esophagram as the gold standard. Swallow-CEUS revealed that in all patients (100%), the UCA was transported from the pharynx to the esophagus while the patient swallowed. ZD appeared as a pouch-shaped structure at the posterior pharyngo-esophageal junction that retained UCA longer than 3 min. The barium esophagram confirmed the diagnosis of ZD in all patients. For the 10 volunteers, no abnormal structure (retaining UCA) was detected during or after swallowing of UCA. With the advantages of no radiation and bedside availability, swallow-CEUS may become a method of choice in confirmation of the diagnosis of ZD, especially when ZD is suspected on conventional ultrasound.

Incidence of bleeding in 8172 percutaneous ultrasound-guided intraabdominal diagnostic and therapeutic interventions - results of the prospective multicenter DEGUM interventional ultrasound study (PIUS study)

PURPOSE

To analyse the incidence of bleeding after percutaneous ultrasound guided diagnostic and therapeutic intraabdominal interventions in a prospective multicentre study (DEGUM percutaneous interventional ultrasound study).

MATERIALS AND METHODS

Within a time period of 2 years diagnostic and therapeutic intraabdominal interventions (with the exclusion of ascites paracentesis) performed percutaneously under continuous ultrasound (US) guidance were prospectively assessed using a pseudonymized standardized web site entry form. Number and type of intervention, operator experience, patient characteristics, medication, lab data as well as technical aspects of the procedure and bleeding complications were analysed according to the interventional radiology standards.

RESULTS

8172 US-guided intraabdominal interventions (liver n = 5903; pancreas n = 501, kidney n = 434, lymph node = 272, biliary system n = 153, spleen n = 63, other abdominal organs and extra-organic targets n = 999) were analysed in 30 hospitals. The majority were diagnostic biopsies including 1780 liver parenchyma, 3400 focal liver lesions and 404 pancreatic lesions. 7525 interventions (92.1 %) were performed in hospitalized patients (mean age 62.6 years). Most operators were highly experienced in US-guided interventions (> 500 interventions prior to the study n = 5729; 70.1 %). Sedation was administered in 1131 patients (13.8 %). Needle diameter was ≥ 1 mm in 7162 punctures (87.9 %) with main focus on core needle biopsies (18 G, n = 4185). Clinically relevant bleeding complications with need of transfusion (0.4 %), surgical bleeding control (0.1 %) and radiological coiling (0.05 %) were very rare. Bleeding complications with fatal outcome occurred in four patients (0.05 %). The frequency of major bleeding complications was significantly higher in patients with an INR > 1.5 (p < 0.001) and patients taking a medication potentially interfering with platelet function or plasmatic coagulation (p < 0.0333).

CONCLUSION

This prospective multicentre study confirms the broad spectrum of percutaneous US-guided intraabdominal interventions. However diagnostic liver biopsies dominate with the use of core needle biopsies (18 G). Percutaneous US-guided interventions performed by experienced sonographers are associated with a low bleeding risk. Major bleeding complications are very rare. A pre-interventional INR < 1.5 and individual medication risk assessment are recommended.

Ultrasound of the pleurae and lungs

The value of ultrasound techniques in examination of the pleurae and lungs has been underestimated over recent decades. One explanation for this is the assumption that the ventilated lungs and the bones of the rib cage constitute impermeable obstacles to ultrasound. However, a variety of pathologies of the chest wall, pleurae and lungs result in altered tissue composition, providing substantially increased access and visibility for ultrasound examination. It is a great benefit that the pleurae and lungs can be non-invasively imaged repeatedly without discomfort or radiation exposure for the patient. Ultrasound is thus particularly valuable in follow-up of disease, differential diagnosis and detection of complications. Diagnostic and therapeutic interventions in patients with pathologic pleural and pulmonary findings can tolerably be performed under real-time ultrasound guidance. In this article, an updated overview is given presenting not only the benefits and indications, but also the limitations of pleural and pulmonary ultrasound.

Measurement of shear wave velocity using acoustic radiation force impulse imaging is not hampered by previous use of ultrasound contrast agents

PURPOSE

To assess the inter-observer reproducibility of acoustic radiation force impulse imaging (ARFI) between 2 skilled physicians and to evaluate if ultrasound contrast agents (UCA) affect the measurement of shear wave velocity (SWV) using ARFI.

PATIENTS AND METHODS

53 patients (29 males, 24 females, 59 ± 15 [22-84] years) who underwent contrast enhanced ultrasound (CEUS) examination were included. ARFI was performed on liver segment V by physicians A and B before CEUS, and by physician A within 4-6 minutes and 7-10 minutes after contrast injection. In a subgroup of 31 patients (15 males, 16 females, 57 ± 18 [22-84] years), ARFI was also performed on focal liver lesions (FLL) by physician A before CEUS, and within 4-6 minutes and 7-10 minutes after contrast injection.

RESULTS

The SWV values obtained by physician A and B before CEUS yielded an intra-class correlation coefficient value of 0.913 (95% CI, 0.849-0.950). No significant differences were shown between the SWV values of liver segment V in all 53 patients and of FLL in the subgroup of 31 patients obtained before CEUS and that of within 4-6 minutes and 7-10 minutes after contrast injection (all P > 0.05).

CONCLUSION

ARFI showed excellent inter-observer reproducibility between 2 skilled physicians. UCA did not affect the measurement of SWV in both liver parenchyma and FLL, at least when performed 4 minutes after the contrast injection. ARFI may become an additional tool in the differential diagnosis of FLL.