UltrasoundMichael Baram

Objectives

• Basic science

• Terminology

• Examples – Movies

• What we should and should not be doing

Disclosures

• Becoming more of a techy.

• I have lost my touch for subclavians

• I tried to trade my kids in for a machine(It did not work)

Anatomy of a wave

• Velocity = wavelength x frequency• High frequency wave travel more linear and

reflected easier

Velocity through material• Velocity of a

wave is a constant through a given substance

(at a constant temperature)

• Assumption made all velocity about 1540 m/s

Medium Speed (m/s)

Blood 1566

Brain 1505-1612

Fat 1446

Kidney 1567

Liver 1556

Muscle 1542-1656

Bone 2070-5350

Water 1480

Air 333

Brass 4430

How waves are made

US- the perfect child

Attenuation

Reflection of Beam

Partial reflection of a sound beam occurs at a tissue interface.

Breast Mass or Cyst?

Different Waves have different degrees of attenuation

Low vs High Frequency

4 MHz 7 MHz

Reasons for attenuation

GAIN

Shadowing

• The lateral edge shadow is a thin acoustic shadow that appears behind edges of cystic structures.  

Shadowing

• artifact is similar to reverberation

Terminology

Image Interpretation:• Anechoic / Echolucent - Complete absence of

returning sound waves, area is black. • Hypoechoic - Structure has very few echoes

and appears darker than surrounding tissue. • Hyperechoic / Echogenic - Opposite of

hypoechoic, structure appears brighter than surrounding tissue.

Terminology Image Acquisition / Probe Positions:• Transverse Plane - Also known as an axial

plane or cross section, separates the superior from the inferior, or, the head from the feet.

• Sagittal Plane - Oriented perpendicular to the ground, separating left from right. The "midsagittal plane" is a sagittal plane that is exactly in the middle of the body.

• Coronal Plane - Also known as the frontal plane, separates the anterior from the posterior or the front from the back.

• Oblique Plane - The probe is oriented neither parallel to, nor at right angles from, coronal, sagittal or transverse planes.

• Longitudinal Plane - The longitudinal plane is perpendicular to the transverse plane an can be either the coronal plane or sagittal plane.

Probe Types

• http://www.youtube.com/watch?v=fntJ7GLjCSU

• http://www.youtube.com/watch?v=VF_OGTSdSlo&feature=channel

• http://www.youtube.com/watch?v=Sb1bM8MnpRk&feature=channel

• http://www.youtube.com/watch?v=XpN1R7A0r_0&feature=channel

What we Should and Should Not DO

Thank you

• Any questions

Fast Exam

• Subxiphoid

 

bladder

• http://folk.ntnu.no/stoylen/strainrate/Ultrasound/

• http://www.sonoguide.com/physics.html