suzanne hecht, md associate professor dept of family med ...forms.acsm.org/tpc2017/pdfs/47...
TRANSCRIPT
Suzanne Hecht, MD
Associate Professor
Dept of Family Med & Comm Health
Program in Sports Medicine
Team Physician; UM Athletics
OVERVIEW Resources
Introduction to MSK US Why?
How does it work?
Types of machines
Advantages
Terms
Normal anatomy
Knee Imaging
Ankle/foot
OBJECTIVES Understand the advantages and disadvantages of
MSK Ultrasound
Recognize the appearance of musculoskeletal structures (bone, muscle, tendon, ligament, & nerve) on ultrasound
Define anisotrophy and techniques to minimize it
RESOURCES American Institute of Ultrasound Medicine
www.aium.org
European Society of Musculoskeletal Radiology www.essr.org
Free instructional videos
University of Michigan http://www.med.umich.edu/rad/muscskel/mskus/
Free instructional videos
AMSSM: “Sports Ultrasound” Sports US Learning Portal
New Position Stand & Fellowship Curriculum
www.amssm.org
RESOURCES
INTRODUCTION: Why MSK US? US plays a role in OB, ER, Cardiology, GI, etc
MSK US
Expanding role in US
Widely used in other countries
Improved technology
Diagnostic & therapeutic
How Does It Work? US = imaging using sound waves
Piezoelectricity
Electricity generates a sound wave
Sound Wave Beam is….
Absorbed
Transmitted
Reflection
Detection
Processing
How Does It Work? Frequency-Resolution
Lower frequency: deeper structures
Higher frequency: superficial structures, better resolution
Higher resolution (> 14 mghz)
Fraction of a millimeter
TYPES OF MACHINES Numerous manufacturers
GE
Sonosite
Samsung
Phillips
etc
Portability Limited
Console
Laptop
Handheld
ADVANTAGES Soft tissue resolution
Accessibility
Side-side
Dynamic
No radiation
No side effects
No contra-indications
Patients love it!
Cheaper than MRI
Guide procedures
DISADVANTAGES Operator dependent
Equipment
You have to buy it!
Training
Courses are expensive
Tip: AMSSM members have access to less expensive courses
Start-Up time
MSK US TERMS Hyperechoic
Bright white on US
High echo
Anechoic Black on US
No echo
Hypoechoic Shades of gray on US
Weak or low echo
NORMAL MSK ANATOMY Tendons
Hyperechoic & fiber-like, longitudinal
Muscles Hypoechoic, but separated with hyperechoic septa
Ligaments Like tendons, but more compact
Connect to two bones together
Nerves “Starry night” or “honeycombed” appearance:
transverse
May appear like tendons in longitudinal axis
TENDONS: ACHILLES
LIGAMENTS: TIBIOFIBULAR
MUSCLES: HAMSTRING
US ARTIFACTS: ANISOTROPY Definition
Anisotropy is the property of being directionally dependent, as opposed to isotropy, which implies homogeneity in all directions.
Occurs when us beam is not directly perpendicular to the tendon/ligament/muscle being imaged
Can give hypoechoic appearance; suggesting injury
Tips Heel & toe the probe
Image in longitudinal & transverse
Orient probe perpendicular to the structure
ANISOTROPY
KNEE US IMAGING Anterior
Quad tendon
Patellar tendon
Patellar retinaculum
Suprapatellar recess
Anterior knee bursae
Medial
MCL
Medial meniscus (partial)
Pes anserinus
KNEE US IMAGING Lateral
LCL
ITB
Lateral mensicus(partial)
Biceps femoris
Common peronealnerve
Popliteus
Posterior
Baker’s cyst
Menisci posterior horns
PCL
ACL
Neurovascular structures
ANTERIOR KNEE
QUAD TENDON: NORMAL
QUAD TENDON: PARTIAL TEAR
SUPRAPATELLAR RECESS
PATELLAR TENDON: NORMAL
MEDIAL KNEE
NORMAL MCL
MCL: PARTIAL TEAR
MEDIAL MENISCAL TEAR
LATERAL KNEE
LATERAL MENISCUS
LCL: NORMAL
POSTERIOR KNEE
BAKER’S (POPITEAL) CYST
TENDONS: ACHILLES
Achilles Tendon
Lateral Ankle
Peroneal Tendons
Peroneal Tendons
PLANTAR FASCIA
Plantar Fascia
SHOULDER: AC JOINT