Endosonography (endoscopic ultrasound) is a combined study in which an ultrasound probe is inserted into the cavity of the esophagus , stomach or intestines with the aid of an endoscope in order to obtain clearer images of deeply located organs. [1] It can be combined with dopplerography to assess blood flow in the vessels, as well as with fine-needle aspiration biopsy [2] .
Principle of the method
Due to the high frequency (5 - 20 MHz) of ultrasound, the resolution of the study increases, which allows us to distinguish between the structures of the intestinal wall and adjacent organs at a distance of 4-6 cm, as well as pathological formations of small sizes [1] .
Diagnostic Application
Endosonography is a method of specifying and differential diagnosis. Diseases for the detection of which endoscopic ultrasound can be used:
- Tumors and pancreatic cysts .
- Pancreatitis (determination of indications for surgery).
- Choledocholithiasis .
- Tumors and inflammatory processes of the mediastinal organs.
- Neuroendocrine tumors of the gastrointestinal tract of small size.
In the studies of Starkov, Solodinona et al. (2009), the diagnostic accuracy of endosonography in identifying dense pancreatic tumors was 94.8%. [1] The method is leading in the detection of tumors of the duodenal papilla, where its diagnostic accuracy is 97.2%, which is much higher than other methods, including duodenoscopy.
In the diagnosis of bile duct stones (choledocholithiasis), endosonography with an accuracy of 90.2% makes it possible to detect calculi with a diameter of 3 mm or less, thus exceeding the capabilities of conventional ultrasound and magnetic resonance cholangiopancreatography. The diagnostic accuracy of the endosonography method can be improved by such modern diagnostic methods as fine needle puncture, Doppler mapping and elastography.
Notes
- ↑ 1 2 3 Starkov Yu. G. et al. Endosonography in the diagnosis of diseases of the hepatobiliary zone // Surgery. - 2009. - T. 6. - S. 10-16.
- ↑ Agarwal B., Abu-Hamda E., Molke KL et al. Endoscopic ultrasound-guided fine needle aspiration and multidetector spiral CT in the diagnosis of pancreatic cancer. Am J Gastroenterol 2004; 99: 844-850.