Diagnostic Musculoskeletal Ultrasound
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Transcript Diagnostic Musculoskeletal Ultrasound
Marc Lederman, DPM
West Hartford Podiatry Associates
March 29, 2014
Disclosures
Consultant- Bioventus
Consultant- Bellevue Pharmacy
Executive Director, CPMA
Outline of the Presentation
1. Basics, Physics and Terminology
2. Indications
3. Scanning of different anatomical sites and structures
4. Office Integration
5. Billing and Coding
Diagnostic Ultrasound gives you an increased ability to
better evaluate and understand soft tissue pathology
and how that relates to the functional mechanics of
the structure being evaluated.
What is UltraSonography and How
Does it Work?
Ultrasound is a longitudinal pressure wave. It is
generated in a device called the transducer, which is
the ultrasound probe.
This is unique in that sound waves are used instead of
ionizing radiation.
The transducer is placed on the skin surface with a
coupling gel (ultrasound gel) and the positioning of
the probe determines what structure, depth and view
is imaged.
Physics of Ultrasound
The ultrasound unit sends an electrical signal to the
transducer which results in a sound wave.
The electrical signal is converted to ultrasonic energy
and back again as the signal is reflected off the
different tissue densities.
As the ultrasonic pulse reflects off the various tissues,
it is converted back to an electrical impulse which is
captured again by the transducer and an image is
produced which is viewed on the monitor.
Imaged Produced
The individual body tissue offers a natural resistance
to the transmission of the ultrasonic pulse.
This is directly proportional to the average density of
the tissue.
Various shades of grey, bright signals and those devoid
of any contrast become the displayed images.
Image Quality
An important consideration is the frequency of the
transducer used for MSK imaging.
For Podiatric use, the frequency of the probe is
between 12-18 MHz
The higher the frequency, the higher the resolution,
but this is at the expense of the depth.
Therefore, a higher frequency is used for a superficial
tendon or joint, 18MHz, and a lower frequency for the
evaluation of a plantar fascia attachment, 14MHz.
Equipment
MyLab®One by Esaote
A Linear transducer with a small head
Portable on a stand or desk top
Touch screen monitor
MyLab is a registered trademark of Esaote S.p.A.
Ultrasound Terminology
Near Field- These are structures that appear in the
upper half of the monitor.
Far Field- Scanned structures and their position is
near the bottom half of the monitor.
Echogenic- These structures generate an echo and are
highly reflective, bright or white on the screen, like
bone.
Anechoic- These do not generate an echo and are seen
as darker or black on the monitor, like a ganglion.
Terminology Continued
Structure patterns which can be Homogeneous
(uniform) or Heterogeneous (irregular).
Hyperechoic- brighter echo like scar tissue or the
surface of bone.
Hypoechoic- less echo, like an area of inflammation
or a partial tendon tear.
Axial resolution- ability to distinguish two objects
when they lie directly over each other.
Horizontal resolution- two objects side by side and
the same distance from the transducer.
Terminology Continued
Anisotropic- having different optical properties in
different directions. The ultrasound image will change
as the angle of the transducer changes. Perpendicular
to the structure is preferred and as the structure
changes direction, for example the posterior tibial
tendon, the image will change if you do not keep the
probe perpendicular. You can therefore lose signal
when evaluating a structure and mistake the image for
pathology.
Indications for Podiatric Ultrasound
Use
Plantar Fascia tears or inflammation
Plantar Fibroma
Achilles Tendon Pathology; tendonosis, tendonitis,
partial or complete ruptures, insertional exostosis
Cystic masses like a ganglion, inclusion cysts
Retrocalcaneal Bursitis
Morton's Neuroma
Bursitis
Ligament strains or tears
Indications Continued
Ankle sprains and ligament pathology
Foreign bodies
Stress fractures
Ultrasound guided injections
Scanning Technique
The terms long and short axis are used to describe how
one positions the transducer to the patient’s foot and
ankle.
You must sit comfortably and have the monitor
positioned in such a manner to make viewing the
screen natural and easy.
Use the heel of your hand and fingers to stabilize the
transducer to the skin surface and move slowly over
the structure to best appreciate the anatomy.
Ultrasound Technique
When evaluating a structure, you rock the transducer
slowly heel to toe, lengthwise with the linear probe
and slowly sweep the probe adjusting to stay
perpendicular to the structure being studied.
On the monitor, you pick the depth, the frequency, the
focal point and adjust the grey zone for the best image.
The physical exam will guide you to the location and
focal point of the ultrasound study.
In USER tab, press preset button to select: Very Superficial,
Superficial, Medium, or Deep.
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Adjust TGC—touching
in this area will make
adjustment available
Adjust Overall Gain
To adjust the Focus, simply touch the screen in the area on which you want to
focus. You will see the focus indicator (the yellow carat on the right-hand side)
move up and down.
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Touch Freeze to freeze the image.
Touch Image to acquire a still image of the frame present on screen at time it is touched.
Color will activate Color Doppler. PwrD will activate Power Doppler.
B+B will allow a split screen and toggle between right or left.
M-Mode will activate an M-Mode line, touching a second time will activate M-Mode.
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Adjust Overall Gain
Color (if Doppler license is present) will display Color Doppler imaging
to enable blood flow visualization. To relocate the color ROI (region of
interest) box, simply touch the screen in the desired area.
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The benefit of Color Doppler
This represents blood flow or inflammation
The red color is moving towards the transducer
The blue is moving away from the transducer
We can see this in tumors, tendon or nerve pathology
where typically we would not expect to see blood flow.
In the inflammatory phase of a tendon injury (10-14
days post injury) the findings would suggest neovascularization.
Buttons can be easily programed to do image and documentary functions
(Freeze, Image, Power Doppler etc.)
MyLabOne Knobology
MyLibrary, on board educational tool. Touch Accept to continue to
anatomic segments and views.
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Very Important
Have a landmark.
Know the anatomy of the part being examined.
Use motion imaging and still images in the evaluation.
Some People are Easier to Scan Than Others.
Water content, the patient’s BMI, fat content and
variations in normal anatomy will effect the scan.
Making adjustments in the gain, the depth and the
probe frequency can help offset the variables.
Using Ultrasound to Evaluate
Common Foot and Ankle Pathology
The Plantar Fascia
The Achilles Tendon
Morton’s Neuroma
Ganglions
Ankle Ligaments
First MTP Joint Pathology
Ultrasound Guided Injections
Long Axis view of the plantar fascia
Short axis view of the plantar fascia
Normal plantar fascia
Abnormal thickness of the fascia
Normal Fascial Attachment
Abnormal Attachment
Long axis view of the Achilles
Tendon
Normal Achilles Tendon Insertion
Achilles Tendon with Calcification
Same Long Axis with more depth
Tendon Pathology in Motion
Short axis view of the Achilles
Tendon
Short Axis Achilles Tendon
Morton’s Neuroma, 3rd innerspace
Dynamic Ultrasound Exam
Ganglion
Angioleimyoma Sub first MTP
Using Color Doppler
Radiograph of Gout First IPJ
Gout First IPJ, Hallux
Gout over IPJ with proximal
extension of inflammation
Gouty Tophi in the IPJ
First MTPJ Pain with Motion
First MTP intra-capsular lesion
Same lesion with joint motion
Plantar Fibromatosis
Synovial Cyst with Neuroma
Evaluation of a Ganglion
Aspiration under Ultrasound
Ganglion
Partial Aspiration of a Ganglion
Office Integration
Charting:
Clinical Presentation including history and c/c
Type of machine, settings and patient positioning
A description of the scanning technique/location
Findings and Impressions
When appropriate, include acoustical impedance,
measurements, and homogeneous or heterogeneous
tissue or mass descriptions.
You can template the structure of the note and make it
specific for the type of tissue or anatomy being
studied.
Just like MRI’s or CT scans, the body of the note can be
repetitive from patient to patient, so long as you
properly and completely report your specific findings
and impressions regarding each patient scanned.
Daily Use in the Office
You do not need a specific room to perform the exams.
Have the staff help by imputing the patient
demographics and setting up the room.
You will be slow in the beginning so put a full
appointment aside for basic exams and re-schedule for
guided injections .
You can integrate the exam images into your EMR.
Billing and Coding
CPT code 76881- Complete exam used for Joint
evaluations.
CPT code 76882- imaging soft tissue structures like
tendons, fascia and lesions.
CPT code 76942- used for guided injections, biopsies
and aspirations.
Conclusion
With the proper training and time Diagnostic
Ultrasound can be well integrated into a busy
Podiatric Office.
Can obtain a specific diagnosis and isolate particular
structures.
Can observe a structure or joint under motion to better
understand the pathology or function.
The patient is informed and part of the exam.
Conclusion
The technique allows for the use of additional
modalities such as PRP and cortisone injections.
Generate an additional source of practice income.
Avoids out of office testing and a quicker diagnosis.
References
Ronald Adler PhD, MD et al. Atlas of Foot and Ankle Sonography,
Lippincott, Williams and Wilkins 2004
Jacobson, Jon MD, Fundamentals of Musculoskeletal Ultrasound,
second edition, Saunders, 2013
Ultrasonographic Evaluation in Plantar Fasciitis, Journal of Foot and
Ankle Surgery, Karaday, Nuri, MD, et al. p442-446
Chih-Kuang, Chen, MD et al. Ultrasound Diagnosis and treatment of
plantar fascia, American J of phys med. Rehabil. 91:182-184
Wen-Cheng, Tsai Ultrasound evaluation of the Plantar Fascia, Scand J
Rheumatol 2000; 29:255-259