Health

What is the relationship between the frequency of ultrasound, depth of penetration, and resolution?  There is an inverse relationship between the frequency of the ultrasound probe and depth of penetration. Standard echoendoscopes typically have a frequency ranging from 5 to 10 mHz, which allows a depth of penetration of 8 and 4 cm, respectively. High-frequency …

Relationship between the frequency of ultrasound depth of penetration and resolution Read More »

Endoscopic Ultrasound Findings Definitions to Describe EUS Findings and Examples of Corresponding Structures Terminology Echogenicity Examples of Structures Anechoic Black Fluid (e.g., blood, bile, pancreatic juice) Hypoechoic Gray (darker than surrounding structures) Lymph node, muscle Hyperechoic Bright (light gray to white) Fat, bone

How does ultrasound work?  Sound waves are vibrations that occur at a specific frequency, are transmitted through a medium, and can be reflected off objects. Information about the direction from which the sound waves are reflected and the time taken for the sound to return from the object can be used to locate the object. …

How does ultrasound work Read More »

What is high frequency ultrasound probe sonography assisted EMR?  A high-frequency ultrasound probe uses a frequency of 20 or 30 mH, rather than 7.5- or 12-mH frequencies used in a conventional EUS transducer. The probe is introduced through the working channel of a standard therapeutic endoscope. The advantage of this probe is that it can …

High frequency ultrasound probe sonography assisted EMR Read More »

Is EUS FNI cholangiography or pancreatography possible? When are they indicated?  Yes. EUS-guided pancreatography and cholangiography can be easily achieved because of the ability of EUS to image the common bile duct and pancreatic duct. Injection of contrast into the ducts can be performed. These techniques are used when ERCP fails to gain access. This …

EUS FNI cholangiography Read More »

What are the potential complications of CPN?  There is a 1% to 2% risk of major complications. Neurologic complications include lower extremity weakness, parathesia, or paralysis. The artery of Adamkiewicz runs along the spine between T8 and L4, and perfuses the lower two thirds of the spinal cord. Spasm or thrombosis of this artery can …

Potential complications of CPN Read More »

What is the success rate of CPN and CPB?  The success rates of CPN and CPB differ. A CPN performed for pain from pancreatic cancer has a reported sustained response of 78% at 2 weeks with a sustained response for up to 24 weeks independent of narcotic use or adjuvant therapy. A CPB performed for …

Success rate of CPN and CPB Read More »