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Objective. We investigated the ability of contrast-enhanced ultrasonography with SonoVue (Bracco SpA, Milan, Italy), a sulfur hexafluoride microbubble contrast agent, to reveal differences between benign and malignant focal splenic lesions. Methods. In a prospective study we investigated 35 lesions in 35 patients (24 male and 11 female; mean age ± SD, 54 ± 15 years) with focal splenic lesions detected by B-mode ultrasonography. After intravenous injection of 1.2 to 2.4 mL of SonoVue, the spleen was examined continuously for 3 minutes using low–mechanical index ultrasonography with contrastspecific software. The final diagnosis was established by histologic examination, computed tomography, or magnetic resonance imaging. Results. In 14 patients, the splenic lesions were malignant (metastasis, n = 6; non-Hodgkin lymphoma, n = 6; and Hodgkin lymphoma, n = 2). In 21 patients, the focal splenic lesions were benign (ischemic lesion, n = 6; echogenic cyst, n = 5; abscess, n = 4; hemangioma, n = 3; hematoma, n = 1; hemophagocytosis syndrome, n = 1; and splenoma, n = 1. Typical findings for benign lesions were 2 arrival patterns: no contrast enhancement (neither in the early nor in the parenchymal phase; P < .05) and the beginning of contrast enhancement in the early phase followed by contrast enhancement in the parenchymal phase 60 seconds after injection. In contrast, the combination of contrast enhancement in the early phase followed by rapid wash-out and demarcation of the lesion without contrast enhancement in the parenchymal phase (60 seconds after injection) was typical for malignant lesions (P < .001). Conclusions. Contrast-enhanced ultrasonography is helpful in the differentiation between benign and malignant lesions of the spleen. Key words: contrast agent; hemangioma; lymphoma; metastasis; SonoVue; spleen; ultrasonography.

Ultrasonography has become increasingly important in the routine diagnostics of gastrointestinal diseases. It is first of all a morphological diagnostic method. As it not only assesses the wall structure of the gallbladder, the pancreatic duct and the whole gastrointestinal tract but also visualises motion sequences as a real-time-method, functional processes and their disruptions can especially be examined. The present authors give a review of the capacity of functional ultrasound in different anatomic zones and critically discuss its practical relevance.

The most common pancreatic tumour is the ductal adenocarcinoma. Many other benign and malignant pancreatic neoplasms have to be recognised and now account for more than 50 % of the pancreatic lesions seen in our daily routine. An improved differential diagnosis is, therefore, mandatory and will be discussed in this review.

Perianal and perineal ultrasound is an effective but rarely applied diagnostic modality. Transmural inflammation, fistula and abscesses in patients with inflammatory bowel disease can be delineated and perirectal tumours can be staged. The method is complementary to endorectal ultrasound. Also oblique transsphincteric fistula can be displayed in detail.

Ultrasound has gained acceptance in the diagnosis of diseases of the gastrointestinal tract beside the classical methods such as endoscopy and X-ray. In a previous publication we discussed the use of ultrasound in emergency diagnostics (e. g., acute appendicitis, diverticulitis/peridiverticulitis, ileus, invagination and perforation) (part 1). Because of the vast extent of this topic, in this overview we will focus on the current role of ultrasound in the detection and assessment of chronic inflammatory bowel diseases, rare forms of colitis (e. g., bacterial, pseudomembranous and neutropenic colitis as well as intestinal tuberculosis), ischaemic bowel diseases as well as diseases of the upper gastrointestinal tract. In chronic inflammatory bowel diseases, ultrasound can give important additional information such as extension, activity, complication (fistula, abscess, stenosis) and in differential diagnosis. It plays an important role in follow-up investigations and can possibly reduce the number of endoscopic examinations. There is still some debate going on about the significance of colour Doppler ultrasound in assessing the activity and differentiation of stenosis. Furthermore, ultrasound is used as a method to guide interventional therapies for abscesses (puncture and drainage). Colour Doppler ultrasound can diagnose ischaemic bowel diseases and also differentiate these from other aetiologies. Ultrasound plays a greater role in the follow-up and assessment of chronic intestinal ischaemia. In the diagnosis of stomach diseases under favourable conditions ultrasound can show changes of the stomach wall, tumours, ulcers and their complication (perforation, penetration) and disturbances of the motility. But an exclusion is not possible.

There is a paucity of data on the sonographic criteria for the diagnosis of intestinal tuberculosis. The purpose of this study was to further characterize the potential sonographic signs of intestinal tuberculosis and to increase the diagnostic sensitivity and specificity of ultrasound.Seven patients with a final diagnosis of gastrointestinal tuberculosis and a control group of 18 patients suffering from tuberculosis limited to the lungs were prospectively evaluated for sonographic criteria of intestinal tuberculosis and the findings were compared with those in 50 healthy controls.The following signs of intestinal tuberculosis were detectable: asymmetric thickened bowel wall (100%), intramural abscesses (86%), fistula (43%), extramural abscesses (29%), mesenteric thickening (29%), "white bowel" sign (29%), hypoechoic edema of Kerckring's folds with mesenterial thrombosis (14%), enlarged mesenteric lymph nodes with inhomogeneous echotexture and circumscribed hypoechoic spots3 mm (86%), ascites (29%) and enlarged spleen (14%). These signs were exclusively present in patients with intestinal tuberculosis as compared with patients with tuberculosis limited to the lungs or with healthy controls. We could confirm the endoscopically reported right-sided prevalence of these wall thickenings. In contrast to the reported literature, a much higher prevalence of these sonographic signs was found as they were present in all patients. Six of 7 patients (86%) showed enlarged mesenteric lymph nodes. This was particularly interesting as mesenteric lymph nodes have not been described as being enlarged in the majority of other differential diagnoses of the ileocecal region.The combination of bowel-wall thickening of the ileocecal region with intramural abscesses with or without fistula, abscesses and mesenteric thickening accompanied by enlarged mesenteric lymph nodes was highly predictive of intestinal tuberculosis.

Contrast enhanced ultrasound (CEUS) is a new imaging method for detection and characterisation of liver tumours. The role of CEUS in pancreatic disease is less obvious. We prospectively evaluated CEUS for characterization of undetermined solid pancreatic lesions (gold standard histology).A total of 112 solitary undetermined pancreatic masses (70 ductal adenocarcinoma and 42 neoplastic nodules of other origin) were prospectively examined in patients without metastatic disease using transabdominal ultrasound. Tumour enhancing features were analyzed in comparison to the surrounding pancreatic parenchyma in patients with adequate visualisation.The sign of iso-hypervascularity as a sign of non-ductal adenocarcinoma showed a sensitivity of 100%, specifity of 90% and accuracy of 93.8%. The sign of hypovascularity as a sign of ductal adenocarcinoma showed a sensitivity of 90%, specifity of 100% and an accuracy of 93.8%.CEUS allows differential diagnosis of ductal adenocarcinoma and non-ductal adenocarcinoma (mainly neuroendocrine tumours and (microcystic) serous pancreatic adenoma) in the most of cases.

Ultrasonography has become widely accepted as a diagnostic tool for gastrointestinal diseases. It not only assesses the lumen but more importantly also the wall and the surrounding structures of the stomach and bowel. Furthermore, functional processes (peristalsis, blood flow) can be visualised and provide important information for passage and perfusion. Modern high resolution (compressive) sonography represents an ideal complementary method besides endoscopy for the gastroenterologist. It is used in emergency diagnosis in cases of acute appendicitis and peridiverticulitis. Here sonography is the method of first choice achieving a high sensitivity. The same applies to ileus, which can be diagnosed significantly earlier by sonography than with conventional X-ray methods. Meanwhile sonography can contribute considerable information to clarify pathogenesis (e. g., invagination, intususception). The detection of a perforation depends strongly on the competence of the examiner. The main advantage is the detection of a covered perforation and the genesis (e. g., ulcer). Ultrasound is less commonly considered in celiac sprue but important complementary information can be obtained. Advanced tumours of the gastrointestinal tract can easily be visualised, although early stages can hardly be detected by means of sonography. An accurate T-staging of tumours is not possible with transabdominal sonography, not least because some parts of the bowel (colon and rectum) cannot always and completely be seen. Exclusion of tumour or early detection is not possible by ultrasound. In intestinal diseases additional information besides clinical and endoscopic aspects can be achieved by ultrasound. Sonography is important for differential diagnosis and follow-up and spares the patient from more incriminatory endoscopic operations. Ultrasound is equal to other imaging methods in detecting complications (fistulas, abscess, stenosis). Due to the complexity of the topic the following review will concentrate on giving an idea of the present status of sonography in chronic inflammatory bowel disease, some less frequent intestinal infections (bacterial, pseudomembranous, neutropenic colitis, intestinal tuberculosis), the ischaemic bowel diseases as well as diseases of the upper gastrointestinal tract.

The diagnostic process, differential diagnosis and continuing routine follow-up of patients with focal liver lesions require an easily available, reliable and cost-effective diagnostic method. Ultrasound is a widely used method for the detection of liver lesions, but it has generally been regarded as inferior to contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI). Recent advances in contrast-enhanced ultrasound (CEUS) have improved the detection rate to a level similar to that attained with CT and MRI. Because of the high spatial resolution of ultrasound, CEUS can also detect metastases smaller than 1 cm. This has been demonstrated in several single-centre studies and recently also a European multi-centre study. This review focuses on the recent advances of CEUS in detecting and characterizing focal liver lesions.

Das «akute Abdomen» bezeichnet einen akut bedrohlichen Zustand mit starken (progredienten) Bauchschmerzen, der wegen der Tendenz zur raschen Verschlimmerung der unverzüglichen Abklärung bedarf; eine prompte chirurgische Therapie ist häufig notwendig. Die zur Diagnostik verfügbare Zeit richtet sich nach der Symptomatik und dem Schweregrad des Krankheitsbildes. In dem vorliegenden Manuskript wird die Bedeutung der Sonographie zur Diagnostik häufiger gastroenterologischer Ursachen des akuten Abdomens dargestellt.

Die Sonographie hat sich in der Diagnostik von Gallenblasenerkrankungen praktisch uneingeschrankt durchgesetzt. Die Sensitivitat liegt bei der Cholezystolithiasis annahernd bei 100%. Die Cholezystitis mit ihren akuten und chronischen Komplikationen ist ebenfalls eine Domane der Sonographie. Gallenblasenpolypen sind gut zu detektieren. Gallenblasenkarzinome werden als maligne Erkrankung des hohen Alters ohne Vorboten meist zu spat diagnostiziert, wenn bereits eine ausgiebige Leberinfiltration vorliegt. In der Abklarung von biliaren Tumoren erweisen sich Ultraschallkontrastmittel (Echosignalverstarker) als hilfreich. Eine Obstruktion der Gallenwege ist leicht zu erkennen, und die Lokalisation lasst sich gut herausarbeiten. Die Abklarung der Genese ist allerdings schwieriger. Die Sensitivitat in der Erkennung der Choledocholithiasis hangt von der Erfahrung des Untersuchers ab und schwankt zwischen 25% und 100%. Die Endosonogaphie ist hier effizienter (94–100%). Die primar sklerosierende Cholangitis (PSC) geht mit perlschnurartigen Gallenwegserweiterungen (70%) und typischen perihepatischen Lymphknotenvergroserungen (annahernd 100%) einher. Die Differenzierung der PSC zum fruhen cholangiozellularen Karzinom fallt schwer. In der Pankreasdiagnostik steht die transabdominelle Sonographie am Anfang der bildgebenden Kaskade. Im Unterschied zu den konkurrierenden radiologischen Verfahren kann die Sonographie ohne Strahlenexposition jederzeit wiederholt werden. Die Aussagekraft hangt allerdings deutlich von der Erfahrung des Untersuchers ab. In der Praxis wird eine Computertomographie dann erganzend durchgefuhrt, wenn die Ultraschalluntersuchung z. B. durch unzureichende Untersuchungsbedingungen unvollstandig war oder Zweifel an der diagnostischen Zuverlassigkeit bestehen. Bei der akuten Pankreatitis sind insbesondere die Beurteilung und die Verlaufskontrolle der Komplikationen (Exsudation, Nekrosebildung, Pseudozysten, Gefaskomplikationen, Obstruktionseffekte) wertvoll. In der Differentialdiagnose der Pankreastumoren ist der Einsatz der Signalverstarker hilfreich. Das duktale Adenokarzinom erscheint uberwiegend mindervaskularisiert, wahrend endokrine Tumoren sowie makro- und mikrozystische Pankreasadenome eher hypervaskularisiert sind.

Differentiation of small and atypical hemangiomas from other hepatic masses using imaging methods can be difficult, especially in patients with underlying malignant disease. Therefore, contrast-enhanced ultrasound was assessed in patients with histologically confirmed hemangiomas with respect to contrast-enhancing kinetics and tumor characteristics. In 58 patients with indeterminate hepatic lesions demonstrated with at least 2 imaging methods (ultrasound/computed tomography/magnetic resonance imaging), ultrasound-guided liver biopsy revealed hemangioma. In all patients a hepatic neoplasm had been suspected because of underlying malignant disease (n = 41), liver cirrhosis (n = 15), or growth of the lesion (n = 2). All patients underwent nonlinear, low mechanical index real-time contrast-enhanced ultrasound scanning with bolus injections of SonoVue. Peripheral nodular arterial enhancement was detected in 43 patients (74%), whereas the typical metastatic peripheral rim-like enhancement was not observed at all. Strong homogenous arterial enhancement was found in 9 of 58 (16%) patients. In 6 patients (10%), the arterial contrast enhancement pattern could not be determined because of the very small size of the lesions or fibrotic nodules. Forty-five (78%) of the hemangiomas showed homogenous centripetal filling within 180 seconds. Conclusion: Contrast-enhanced ultrasound demonstrates typical hemangioma imaging characteristics, that is, peripheral nodular contrast enhancement and iris-diaphragm sign in a high percentage of patients with undetermined lesions. This technique may therefore improve noninvasive functional characterization and differentiation of hemangiomas. (HEPATOLOGY 2007;45:1139–1145.)

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

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.

This review summarizes ultrasound guided interventions in palliative care medicine.

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.

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).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.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).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.

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).

Conventional B-mode and colour duplex imaging is the first choice imaging technique after history taking and physical examination and for the interpretation of laboratory parameters. In the hands of a gastroenterologist ultrasound has become an equally important diagnostic tool as endoscopy. The constantly evolving technique with its possibility of higher resolution by use of "harmonic imaging" and signal enhancement with contrast medium is the reason for a practically relevant review of the situation. Practical references will be given for diagnostics of the liver and portal system including the spleen. The significance of the sonographic diagnosis of "fatty liver" is critically discussed. The overall importance of ultrasound to distinguish different aetiologies of diffuse liver diseases is relatively low. Nevertheless, it is a very sensitive means to detect complications of liver cirrhosis. Portosystemic shunts and typical changes in blood vessel morphology can be diagnosed by colour duplex sonography and used as indirect signs of advanced damage to liver parenchyma. In addition, ultrasound has its value in the confirmation or exclusion of dilated bile ducts as well as in the detection and differentiation of circumscribed liver lesions. The characterisation of focal liver lesions by ultrasound is sufficient in typical cases. The use of ultrasound contrast media (signal enhancers) raises the rate of differentiation and can avoid the uncritical and sequential application of radiological imaging (computed tomography [CT] or magnetic resonance imaging [MRI]). If in doubt about the nature of a lesion, a histological diagnosis remains indispensable. The examination of the spleen and its feeding vessels is regularly done in cases of diffuse parenchymal liver disease when searching for its complications, e. g., portal hypertension. Focal spleen lesions can be observed especially in the context of lymphoma (infiltration) and other bone marrow diseases. Through the application of contrast media, changes of vascularisation (e. g., infarcts) can be visualised and traumatic lesions can be diagnosed more precisely.

AIM: Recent advances in technology have supported the development of new endoscopic ultrasound systems making it possible to use low MI contrast-enhanced imaging techniques (wide band harmonic imaging done with endoscopic ultrasound is currently at a preliminary stage). We now report on the first use of contrast-enhanced, low mechanical index, real-time endoscopic ultrasound (CELMI-EUS) in six patients using prototype technology. MATERIALS AND METHODS: CELMI-EUS was performed using an electronic echo-endoscope HITACHI/Pentax EG-3830UT and adapted dynamic contrast harmonic wide-band pulsed inversion software with low mechanical index (MI = 0.09 - 0.25) before and up to 180 seconds after injection of SonoVue (4.8 mL) in six patients. RESULTS: Adequate visualisation of the arterial and portal venous phases was achieved in all patients. The pancreas and liver were studied thereafter. In contrast to the satisfactory visualisation of these vessels, enhancement of the left liver lobe was sufficient only in 4 patients. In the remaining 2 patients with liver cirrhosis, the enhancement was less pronounced in contrast to the strong enhancement of the hepatic artery and portal vein. CONCLUSION: Recent advances in technology have supported the development of new echo-endoscopic systems making it possible to use real-time, low mechanical index, contrast-enhanced imaging techniques with endoscopic ultrasound. We have preliminarily shown that arterial, portal venous and parenchymal contrast enhancement is possible.

We report on a 49-year-old male patient who was suspected to have a malignant liver tumour with enlarged perihepatic lymph nodes because of CT and ultrasound scanning. To verify the diagnosis and procure a histological specimen, the patient underwent laparotomy. Histologically, an inflammatory pseudotumour could be confirmed. This is a rare disease which can present with fever, abdominal pain, vomiting and weight loss indicating malignancy or abscess. The definite diagnosis is often only verified by surgery.

Contrast-enhanced ultrasound techniques represent the most challenging efforts in recent ultrasound developments. Contrast-enhanced imaging of the liver will be reviewed with respect to the literature and our own experience. Echo-enhancing agents, also known as ultrasound contrast media, have improved the accuracy of liver ultrasound within recent years. The characterisation of focal liver lesions which is possible by flow characteristics and the improved detection of liver tumors give special importance to the contrast agents. The agents consist of air or gas bubbles coated with different shell media. These micro-bubbles act as strong reflectors to the ultrasound beam enhancing the backscatter signal up to 30 dB. There are differences between blood pool agents and agents with a liver-specific late phase. The agents remain in the vessels during the vascular phase and lead to enhancement of different structures (arterial, capillary, portal venous, and sinusoidal perfusion). This is the first real-time imaging technique of liver lesions that allows a unique analysis of tumor perfusion. Liver tumors known to be hyperperfused in the arterial phase (e. g., focal nodular hyperplasia, hepatocellular carcinoma, and hyperperfused metastases) can be detected and characterised. Hypoperfused tumours (e. g., liver metastases of the gastrointestinal tract) can be recognised in the portal venous phase as less perfused "black spots". Due to of the recently available improved ultrasound technology and affordable ultrasound systems, a reduction in the use of computed tomography (CT) and magnetic resonance imaging (MRI) may be possible, allowing these important technologies to be available for other indications (e. g., brain, thorax).

Hepatic blood flow has been investigated using color Doppler ultrasonography in patients with liver disease, especially in patients with portal hypertension (e. g. liver cirrhosis, portal vein thrombosis, Budd-Chiari-syndrome). Duplex examination protocols, however, differ considerably because no standard technique has been established so far. Whereas there is an agreement about the angle of the ultrasound application (< 60 degrees ), neither the exact location nor the relevant examination parameters have been standardized. Based on a search of the relevant literature, published examination techniques and results were analyzed. These findings are to serve as a basis for a prospective multicenter study for the determination of standard values.

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 90% of pNETs.

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.