Contrast-enhanced ultrasound of small focal solid pancreatic lesions: A must!

Early detection of pancreatic tumors by advanced EUS imaging

The early detection of pancreatic ductal adenocarcinoma (PDAC) dramatically improves outcome. All available state-of-the-art imaging methods allow early detection with EUS being the best technique for exclusion of PDAC and detection of very early PDAC. Etiological differentiation of small SPL is important to guide individually tailored patients' management including radical surgery in resectable PDAC, medical (neoadjuvant or palliative intended) treatment in patients with non-resectable malignancy, pancreatic parenchyma saving strategies in some non-PDAC, and follow-up in particular in low-grade PanNEN or other small benign lesions. Multimodality EUS imaging including B-Mode assessment, elastography, contrast-enhancement and EUS-guided sampling is the most appropriate technique for diagnosis and risk assessment of small SPL. We present a review discussing modern (endoscopic) ultrasound imaging techniques including contrast enhanced ultrasound and elastography for the early detection and characterization of solid pancreatic lesions.

[All about the Pancreas]

All about the Pancreas Abstract. Ultrasound has made tremendous progress with the use of contrast media and elastography, particularly in patients with small, solid pancreatic lesions (SPL) <20mm and cystic tumors (CPL) of any size. In the case of solid and cystic pancreatic lesions, the differential diagnosis must first be evaluated after detection in order to define the indications for radical surgery, strategies for preserving the pancreatic parenchyma or simply for control examinations. Contrast-enhanced transcutaneous (TUS, CEUS) and endoscopic (EUS, CE-EUS) ultrasound and elastography facilitate further characterization of SPL and ZPL. Pancreatic ductal adenocarcinomas (PDAC) show hypoenhancement in contrast-enhanced ultrasound. The majority of the important differential diagnoses, on the other hand, are multi-enhancing. PDAC are almost always harder than healthy pancreatic parenchyma. In contrast, elastographically soft SPL are - with very few exceptions - benign. This review provides an overview of the use of modern ultrasound techniques to detect and characterize solid and cystic pancreatic lesions.

Update in Contrast-Enhanced Ultrasound

BACKGROUND

The aim of modern medicine is to safely classify diseases for successful therapy without invasive measures. Sonography, computed tomography (CT), and magnetic resonance imaging (MRI) are potent imaging techniques. However, without contrast medium, the informative value of the 3 native methods is limited. The advantages of sonography are: no radiation exposure or previously known physically harmful interactions with tissue, proportionate disappearance of a contrast agent risk, no (probably irreversible) contrast agent deposits, and no risk of renal insufficiency. But, is that enough to compete with of even exceed CT and MRI?

SUMMARY

In this review, the state of the art of contrast-enhanced ultrasound (CEUS) in the abdominal cavity is presented. The remarkable diagnostic possibilities can unfortunately only be demonstrated here in a small number of impressive, typical case studies underpinned by the literature, so that, from one's own perspective, the full spectrum of CEUS can be used by oneself or initiated. Within the limits of physics, the real-time dynamics of CEUS enable conclusions to be drawn, so that with the current technology, sonography, including expansion by contrast, can be considered superior to other imaging methods. It is not uncommon for CEUS to have the value of a control and reference method.

KEY MESSAGES

Sonography very often enables reliable diagnostics. The introduction of a contrast agent in sonography has led to a quantum leap similar to that of other imaging techniques. Already natively, the real-time representation of dynamic events leads to a certain superiority, i.e., complete observation of the inflow and outflow phases of the contrast medium and the resulting diagnostic; tissue-specific differentiation options provide a unique selling point. Further advantages of the first-choice imaging diagnostic method are: a lack of radiation exposure, repeatability of the examination at any time, local independence, a negligible allergy rate compared to the contrast agents of other methods, and a lack of kidney and thyroid exposure or excluded deposits.

The Role of Endoscopic Ultrasound and Endoscopic Resection for Gastric Glomus: A Case Series and Literature Review

Background and Objectives

Preoperative diagnosis of gastric glomus tumor is very difficult, and there are few reports regarding the endoscopic treatment of glomus tumor of the stomach. Our aim is to provide a retrospective assessment of the imaging features of endoscopic ultrasound (EUS) and treatment of choice of gastric glomus tumor.

Methods

A database of all patients with gastric glomus tumor who was treated at Shengjing Hospital of China Medical University between March 2011 and March 2017 was retrospectively analyzed. The EUS characteristics and patients’ clinical data as well as their treatment were reviewed. At the same time, we compared EUS characteristics of gastric glomus tumor with that of gastrointestinal stromal tumor (GISTs), leiomyomas, schwannomas, and ectopic pancreas.

Results

Eleven patients (3 male and 8 female patients) were included in the present study. The patients’ age ranged from 37 to 62 years (mean age, 50.1 years). Ten patients received EUS examination. Eight lesions were presented with mild-hyperechoic round or oval mass; one lesion was mild-hyperechoic oval mass with hypoechoic spots; one lesion was hypoechoic oval mass. One patient received endoscopic full-thickness resection; 3 patients were treated by endoscopic submucosal dissection; and laparoscopic resection was performed for 7 patients.

Conclusions

Gastric glomus has typical EUS features to differentiate from other submucosal tumors. Compared with surgery, endoscopic resection is also a safe and effective treatment of choice for gastric glomus tumor.

Modern ultrasound imaging of pancreatic tumors

In patients with solid pancreatic lesions (SPLs), the differential diagnosis must be evaluated to determine whether radical surgery, pancreatic parenchyma-saving strategies, or follow-up is indicated. Contrast-enhanced (endoscopic) ultrasonography and elastography facilitate the further characterization of SPLs. The majority of cases of pancreatic ductal adenocarcinoma exhibit hypoenhancement with contrast-enhanced ultrasonography. Elastographically soft SPLs are benign with very few exceptions, whereas stiffer SPLs can be malignant or benign. This article reviews the current use of modern ultrasound imaging techniques, including contrast-enhanced ultrasonography and elastography, for the detection and characterization of SPLs. In particular, the unexcelled diagnostic potential of multiparametric endoscopic ultrasonography to detect and characterize small SPLs is highlighted.

CO 2 vs. air insufflation in endoscopic ultrasonography: a prospective study

Background and study aims  Carbon dioxide (CO ₂ ) is being increasingly used for insufflation during endoscopy for safety and better tolerance. The role of CO ₂ during endoscopic ultrasonography (EUS) has not been studied yet. Our main aim was to compare the effects of CO ₂ vs. air insufflation on abdominal discomfort in patients undergoing EUS. Our secondary outcomes were to ascertain the effects of CO ₂ insufflation on image quality/visual artifacts and on the amount of sedation. Patients and methods  This was a prospective, controlled, single-blind, observational study. Abdominal discomfort was assessed before diagnostic EUS, and 1 and 3 hours post-procedure and recorded as a visual analogue scale. Image quality was also recorded as a 4-point scale from optimal to poor at four different scanning sites (esophagus, stomach, duodenal bulb and second portion). Results  A total of 198 patients were enrolled. We observed that CO ₂ resulted in less abdominal discomfort than air insufflation that was statistically significant at 3 hours ( P  = 0.048) but not at 1 hour after EUS ( P  = 0.112), probably due to the ongoing effects of sedation at the latter stage. On the other hand, no differences were found in the dose of sedation administered in the two groups. Image quality was significantly better in the CO ₂ group compared to the air group at all four different scanning sites ( P  < 0.01). Similarly, CO ₂ correlated with less visual artifacts and need of suction ( P  < 0.01). Conclusions  Similarly to previous findings with other endoscopic procedures, EUS was associated with improved scores for abdominal discomfort with CO ₂ rather than air insufflation. Moreover, overall EUS image quality was improved using CO ₂ insufflation. Future studies are warranted to ascertain whether CO ₂ insufflation should be regarded as the standard of care for diagnostic EUS.