Ultrasound is an imaging technology used to visualize the abdominal cavity, allowing physicians to detect abnormalities within the gastrointestinal tract. However, ultrasound is limited in that it can only visualize the abdominal organs and surrounding structures. However, it cannot clearly visualize deeply situated organs behind the stomach, such as the pancreas and biliary tract.  Today, a newer technology known as Endoscopic Ultrasound (EUS) has been developed, enabling physicians to obtain more detailed and in-depth images of the gastrointestinal system.
What is Endoscopic Ultrasound?
Endoscopic Ultrasound (EUS) is a procedure for examining the gastrointestinal tract by using an endoscope equipped with an ultrasound device. This technique allows physicians to visualize the lining and wall of the gastrointestinal tract from the upper esophagus, stomach, and proximal small intestine to the distal colon and rectum. EUS can also be used to examine nearby organs, such as the gallbladder and liver that cannot be adequately visualized with conventional external ultrasound.
What is the process of EUS?
An EUS procedure involves inserting a flexible endoscope equipped with an ultrasound probe through the mouth or rectum. The endoscope is guided to the target area, where ultrasound waves are used to produce images of the gastrointestinal tract.
Benefit of Endoscopic Ultrasound (EUS)
•    Diagnostic aspect
•    Detection of Gallstones in the Bile Duct Without the Need for ERCP
In the past, if doctors suspected gallstones in the bile duct, they would perform Endoscopic Retrograde Cholangiopancreatography (ERCP), a complex procedure with several risks, such as bowel perforation, bleeding in the bile duct, and pancreatitis. Therefore, if the physicians would like to diagnose whether the patient gallstones in the bile duct, EUS can be used instead; this can minimize the risks associated with ERCP
•    Tissue Biopsy Without Significant Discomfort
When a tissue sample is needed for diagnosis of suspected pancreatic cancer or abnormalities in lymph nodes, EUS can provide a detailed view of the organs through the abdominal wall. With EUS, a specialized tool can be attached to the endoscope to collect tissue samples for further analysis. This allows for a more accurate and comprehensive diagnosis in a single, minimally invasive procedure."
•    Treatment aspect
•    Treating Bile Duct Obstructions Without the Need for an External Drainage Bag:
In cases where a patient has bile duct obstruction due to cancer or narrowing of the bile duct, leading to jaundice, doctors may need to perform a biliary drainage procedure to restore normal function. Traditionally, this involves creating an external biliary drainage that results in the patient having a permanent abdominal bag. However, advancements in medical technology have introduced Endoscopic Ultrasound (EUS) as an alternative treatment.

This technique involves attaching devices to an ultrasound camera, allowing physicians to create a new pathway for bile drainage more easily. Although EUS carries higher risks and costs compared to Endoscopic Retrograde Cholangiopancreatography (ERCP), it offers significant benefits. Notably, EUS can alleviate jaundice symptoms without requiring the patient to live with an external bag for the rest of their life.