Matt Dawson MD, RDMS, RDCS University of Kentucky Director of Emergency Ultrasound

MESA Director of Ultrasound

Soft Tissue Ultrasound

Monday, May 6, 13

Case

• 63 y/o Male presents with redness, pain and swelling to his Leg.

• Cellulitis......abscess?

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What do you do?

• Incise?

• Antibiotics and home?

• CT?

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Ultrasound

AntibioticsDrainOR

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Necrotizing Fasciitis

Send to OR

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What Just Happened?• Cellulitis: You saved the patient a painful

procedure

• CT: resources/radiation

• Abscess: You prevented an ineffective treatment (antibiotics alone)

• Nec Fasc: You may have saved their LIFE!

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Not Me!• “I’ve been doing this for years without

ultrasound......”

Dr. Oz

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50%!!!• Ultrasound changed the management of patients

with cellulitis in 71/126 (56%) of cases.• Tayal VS, Hasan N, Norton HJ, Tomaszewski CA.

The effect of soft-tissue ultrasound on the management of cellulitis in the emergency department. Acad Emerg Med. 2006;13(4):384-8.

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Soft Tissue Infections: Why ultrasound?

• Physical exam alone can be misleading

• May prevent unnecessary painful procedures

• Prevents ineffective treatment

• Helps localize and direct drainage procedures

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Goal of exam

• Identify one of the following three findings:

• Abscess

• Cellulitis

• Normal Skin

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Probe Selection

• Linear Probe

• High Frequency

• Advantage: Excellent image resolution

• Disadvantage: Shallow imaging only

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Scanning Technique• Scan in two planes

• Adjust depth: view in both far and shallow fields

• Use doppler to ID surrounding vascular structures

• Consider water baths

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Scanning in two planes

• Image is 2D

• Abscess is 3D

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Water Baths

• Water is an excellent conductor of sound

• Probe is sealed

• Non painful exam

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Other Option

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Water Bath

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Normal Skin

• Skin

• Subcutaneous fat

• Fascia

• Muscle

• Vascular structures

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Cellulitis• Cobble Stoning

• Increased echogenicity of the subcutaneous tissue

• Fluid and infection between lobules in the subcutaneous tissue

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Cellulitis• Cobble Stoning

• Increased echogenicity of the subcutaneous tissue

• Fluid and infection between lobules in the subcutaneous tissue

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Cellulitis• Cobble Stoning

• Increased echogenicity of the subcutaneous tissue

• Fluid and infection between lobules in the subcutaneous tissue

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Skin Abscess• Abscess cavity with

surrounding cobblestoning

• Typically spherical

• Abscess is anechoic or mixed echos with debris

• Pressure induces movement of purulent material

Monday, May 6, 13

Skin Abscess• Abscess cavity with

surrounding cobblestoning

• Typically spherical

• Abscess is anechoic or mixed echos with debris

• Pressure induces movement of purulent material

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Management

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Foreign Body Localization

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Foreign Body Localization

• Challenging

• Hand and foot most commonly affected, high risk of iatrogenic injury from blind exploration

• Ultrasound can guide removal in real time

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Disclaimer

• NOT EASY!

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But....• It’s the best we have

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WoodUltrasound is more sensitive than CT for wood Foreign Body

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Metal and GlassMetal and glass usually radio-opaque

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Organic Matter and PlasticOrganic matter and plastic are radiolucent: Does not show up on x-rays

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Foreign Bodies• Most common

radiolucent foreign body is wood (hand and foot)

• Anatomy can be confusing, scan the contralateral extremity

• Most radiolucent foreign bodies are superficial (<2cm)

Monday, May 6, 13

Foreign Bodies• Most common

radiolucent foreign body is wood (hand and foot)

• Anatomy can be confusing, scan the contralateral extremity

• Most radiolucent foreign bodies are superficial (<2cm)

Monday, May 6, 13

Foreign Bodies• Most common

radiolucent foreign body is wood (hand and foot)

• Anatomy can be confusing, scan the contralateral extremity

• Most radiolucent foreign bodies are superficial (<2cm)

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• FB Examples

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• FB Examples

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• FB Examples

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• FB Examples

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• FB Examples

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• FB Examples

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Things to watch out for

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Lymph Nodes

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Reactive Lymph Nodes

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Reactive Lymph Nodes

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Reactive Lymph Nodes

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Reactive Lymph Nodes

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• Pseudoaneurysm

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• Pseudoaneurysm

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• Never mismanage a cellulitis/abscess again!

• Quit guessing and sleep well after your decision about the “red leg”.

Summary

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Monday, May 6, 13