Endoscopic ultrasound elastography: Current status and future perspectives

Abstract

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.

Current Knowledge in Ultrasound-Based Liver Elastography of Pediatric Patients

“…The summary sensitivity was 81% (95% CI: 71-88) and the specificity was 91% (95% CI: [83][84][85][86][87][88][89][90][91][92][93][94][95][96] for the prediction of significant liver fibrosis. Subgroup analysis revealed that 2D-SWE had an excellent diagnostic performance according to each degree of liver fibrosis.…”

“…Real-time elastography (RTE) has been used mainly for the evaluation of the pancreas [83][84][85][86], the thyroid [87][88][89][90][91][92][93][94], the prostate [95], the breast [5,96] but also for the liver [1,2,7,97]. Published evidence in children is scarce and contradictory [98][99][100].…”

Elastographic Assessment of Xenograft Pancreatic Tumors

“…However, EUS-guided biopsy is difficult, often requiring multiple punctures to obtain a sufficient number of tissue samples. Several researchers have reported that endoscopic ultrasound elastography can differentiate benign from malignant pancreatic tumors and lymph nodes with high accuracy (Cui et al 2015; Iglesias-Garcia et al 2017). Despite these encouraging results, endoscopic ultrasound elastography is invasive and currently only available on one commercially available system, Hitachi’s EUB-8500 system.…”

General advice in ultrasound based elastography of pediatric patients

“…There are different kinds of settings, where measurements can be done transdermally or in a trans-rectal endoscopic setting [53,58,90]. EUS elastography offers a high resolution of the digestive tract, close view of organs and lymph nodes [91,92]. Elastography techniques have been used in different ways in different studies; dynamic elastography shows promising results while SE has a lower cost, which makes this technique more accessible [73].…”