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.

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.

It is time for a change. CEUS is an established method that should be much more actively included in renal cyst monitoring strategies. This review compares the accuracies, strengths, and weaknesses of CEUS, CECT, and MRI in the classification of renal cysts. In order to avoid overstaging by CEUS, a further differentiation of classes IIF, III, and IV is required. A further development in the refinement of the CEUS-Bosniak classification aims to integrate CEUS more closely into the monitoring of renal cysts and to develop new and complex monitoring algorithms.

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. Zystische Läsionen in der Leber und den Nieren sind häufige Zufallsbefunde. Sie sind in der Regel benigne und bedürfen keiner Behandlung. Sie können sporadisch oder als Teil von Syndromen auftreten und sind durch ihre echofreie Struktur und der dorsalen Schallverstärkung im Ultraschall charakterisiert. Eine Größenzunahme, Einblutung oder Infektion der Zyste kann zu Beschwerden führen. Die ultraschallgesteuerte Sklerosierungtherapie symptomatischer Zysten stellt neben den chirurgischen Optionen, wie die laparoskopische Zystenentdachung eine sichere minimalinvasive und effektive Behandlungsoption dar.

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 ac