Peter Rippey, MD, CAQSM
PCSM Fellowship Director
Associate Professor Family Medicine
University of South Alabama
Introductions
Ultrasounds have classically been used in the radiology department to scan your bladder area. Over time, they are used for different areas and the size has gotten smaller and smaller.
Physics of Ultrasound
Ultrasounds use sound and frequency in scans. Sound is a pressure wave propagated through a medium. Frequency is one positive and negative pressure change cycle/s or Hz (the human hearing is 20-20,000Hz).
Because of the physics used through radiology, a gel is applied to the area that is being scanned. This helps the waves go through easier than it would without the gel because of the many other things it would pick up.
Limitations & Benefits
You are required to have a certain amount of training to operate the ultrasound. If not properly used, it can make it look like there is an injury that is not actually there. It also has a limited field of view; you cannot see inside joints or past the bone cortex. Sometimes, other providers may not be able to interpret but there is also many benefits.
Facts such as anyone can be scanned, it is fairly cheaper, provides dynamic imaging, the ability to intervene at same as diagnosis, provides a side to side comparison, high availability, point of care, doppler, and supeior resolution over MRI.
Indication/Uses
*Evaluation of joint and extremity pain
*Evaluation of peripheral nevers
*Examining masses
*Rheumatologic conditions
*Image guided injections / aspiration / procedures
Tissue Types
*tendon: alternating hyper and hypoechic lines
*patellar
*muscle: hypoechoic muscle fibers
Ligaments
*intermediate echogenicity
Dynamic US allows for stress of the ligament to see if its injured
Bone
Ultrasounds cannot see through bone.
Increasingly US is used to asses for fractures. Erosions from RA are visible on US prior to x-ray.
Nerve
Nerves are similar to tendons but less tightly packed
*Hypoechoic fascicles, surround by hyperchoic epineurium
*honey comb pattern
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