BRUNO OTILIOCiência sem Fronteiras

Internship at Mayo Clinic

INTRODUCTIONPlaces that I lived on

Bloomington, IN

Brookings, SD

Rochester, MN

A brief definition on Ultrasound

What is that?

Internship

Mayo Clinic

Elastography

My fronts

BLOOMINGTON, IN

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There were squirrels on everywhere!!

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BROOKINGS, SD

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ROCHESTER, MN

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“THE FUN TIME FINISHED AND THE WORK TIME HAS BEGUN”

Stewie Griffin - Family Guy

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ULTRA-WHAT?What is a sound?

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SOUND

[1] - http://healthstoriesforkids.com/the-journey-of-ear-infections/

[2] - http://hyperphysics.phy-astr.gsu.edu/hbase/sound/tralon.html

[1]

[2]

Mechanical Electric

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What frequency can humans hear? -> 20Hz - 20kHz

[3] - http://healingsounds.co.za/content/about-sound-1

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Ultrasound = f>20kHz

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IF HUMANS CANNOT HEAR IT… WHY IS THAT IMPORTANT?

[4] - http://www.raymarine.com/view/?id=3173

History: – First practical application, 1912 unsuccessful search

for Titanic

– WWII brought massive military research-SONAR (SOund Navigation And Ranging) -> SONAR

– Mid-century used for non-destructive testing of materials

– First used as diagnostic tool in 1942 for localizing brain tumors

– 1950’s 2D gray scale images

– 1965 real-time imaging

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SONOGRAPHY ULTRASOUND IMAGING ➤It uses high-frequency sound waves to view inside

the body.➤They can also show movement of the body's

internal organs as well as blood flowing through

the blood vessels.➤Unlike X-ray imaging, there is no ionizing

radiation exposure associated with ultrasound imaging.

➤A transducer is placed directly on the skin or inside a body opening.

➤ Gel is applied to the skin so that the ultrasound waves are transmitted from the transducer through

the gel into the body.➤The ultrasound image is produced based on the

reflection of the waves off of the body structures.➤The strength (amplitude) of the sound signal and

the time it takes for the wave to travel through the body provide the information necessary to produce an image.http://www.medicalnewstoday.com/articles/245491.php?page=2

http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/ucm115357.htm21

HOW IS ULTRASOUND CREATED?

GE LogiQ 7 Transducers

http://www.vaultrasound.com/educational-resources/ultrasound-physics/transducers/

Verasonics

In medicine, ultrasound (f > 1 MHz) is used to detect changes in

appearance, size or contour of organs, tissues, and vessels or detect

abnormal masses, such as tumors.

Radiologyinfo.org

(typically 20–600 V at 1 kHz).

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TRANSDUCERS AND IMAGING

➤ Transducer element: > 256 elements measuring 1mm X 10 mm each.

➤ Real-Time US -> 16 frames/sec must be displayed.

➤ Doppler Ultrasound: Doppler ultrasound, a special application of ultrasound, measures the direction and speed of blood cells as they move through vessels.

Acoustic waves’ velocity depends of the medium.http://ultrasound-scanner.com/5-2-color-doppler-ultrasound-system.html

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ULTRASOUND QUANTITIES AND UNITS

➤ Frequency: The range of 2 - 10 MHz.

➤ Propagation Speed: Typically, 1540 m/sec for soft tissue.

➤ Pulsed ultrasound: To achieve the depth of resolution (milliseconds)

➤ US interaction with tissue: Attenuation

➤ Angle of Incidence (Snell’s law)

24Gel is important for that!!

Transducer

High frequency Low frequency

better resolution weak resolution

attenuation attenuation

REFERENCES ➤ John E. Aldrich, PhD. Basic physics of ultrasound imaging ➤ Jens E. Wilhjelm, Andreas Illum, Martin Kristensson and Ole Trier Andersen. Medical diagnostic

ultrasound - physical principles and imaging. Biomedical Engineering, DTU Elektro Technical University of Denmark

➤ P N T Wells. Ultrasonic imaging of the human body. Department of Medical Physics and Bioengineering and Centre for Physics and Engineering Research in Medicine, Bristol General Hospital, Bristol BS1 6SY, UK.

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