Standard

Posted: 11/14/07

R State Standard         £  Institutionally Developed          College: N/A

 

VAS 215 - Vascular Physical Principles & Instrumentation Registry Review

 

Course Description

Provides a review of basic knowledge from previous courses and helps the student prepare for a national certification examinations for sonography.   Information concerning test taking skills will also be reviewed.  Course review includes  physics, patient care, equipment/image manipulation, scanning procedures, bioeffects and safety.  Emphasis will be placed on those items/issues/topics which are part of the certification examination. Topics include: propagation of ultrasound through tissues, principles of pulse echo imaging, quality assurance of ultrasound instruments, elementary principles, bioeffects and safety, ultrasound transducers and pulse echo instruments.

 

Competency Areas

Hours

Propagation of Ultrasound through Tissues

Class

2

Principles of Pulse Echo Imaging

D. Lab

0

Quality Assurance of Ultrasound Instruments      

P. Lab/O.B.I.

0

Elementary Principles

Credit

2

Bioeffects and Safety

 

 

Ultrasound Transducers

 

 

Pulse Echo Instruments

 

 

 

Prerequisite:

DMS 136, DMS 202

Corequisite:

     

 

Course Guide

 

Competency

After completing this section, the student will be able to:

Hours

Class

D.Lab

P.Lab/

O.B.I.

Propagation of Ultrasound through Tissues

3

0

0

 

Review the concepts surrounding transmission of sound through tissues including

a.    Propagation speed

i.         Stiffness

ii.       Density

b.    Compression and rarefaction

c.    Angle of incidence

d.    Impedance

 

 

 

Principles of Pulse Echo Imaging

3

0

0

 

Review the principles that govern transmission of sound into patients and the changes affecting the sound beam’s return to the transducer to include:

a.    Impedance mismatch

b.    Reflection/refraction

 

 

 

 

Review the display and recording of images

       a.  Echogenicity

 

 

 

 

Review homogeneity.

 

 

 

Quality Assurance of Ultrasound Instruments       

2

0

0

 

Demonstrate the general concepts regarding the need for and nature of a quality assurance program

 

 

 

 

Compare and contrast the methods for evaluating instrument performance to include:  

a.    Test objects

i.         Phantoms (tissue, Doppler, flow)

ii.       Parameters to Be Evaluated

iii.      Test object

iv.      Dead zone

v.        Axial resolution and lateral resolution (beam width)

vi.      Depth calibration accuracy

vii.     TGC characteristics

viii.   Uniformity

ix.     system sensitivity

b.    Tissue equivalent (mimicking) phantom to include:

i.         Dead zone

ii.       Depth calibration accuracy

iii.      Lateral (horizontal) distance measurement accuracy

iv.      Axial, lateral, and section thickness (elevational) resolution

v.        GC characteristics

vi.      System sensitivity

vii.     Dynamic range

viii.   Contrast resolution

ix.     Lesion detection

c.    Doppler flow, string, or belt phantoms to include:

i.         Maximum depth

ii.       Pulsed Doppler sample volume alignment (gate position accuracy)

iii.      Velocity accuracy

iv.      Color flow penetration

v.        Image congruency test

 

 

 

 

Organize and plan a preventive maintenance program.

 

 

 

 

Practice standard precautions in regards to equipment cleaningto include:  

a.       Cleaning

b.       Disinfecting

c.       Sterilization

 

 

 

 

Summarize the details record keeping.

 

 

 

 

Calculate Statistical Indices to include:

a.       Sensitivity/specificity

b.       Negative/positive predictive value

c.       Accuracy

 

 

 

Elementary Principles

4

0

0

 

Review and discuss the properties of sound including

a.    The relationship of wavelength, frequency and propagation speed

b.    The relationship between amplitude, power, pressure and intensity

c.    The factors affecting  to include:

i.         Reflection

ii.       Refraction

iii.      Attenuation

iv.      penetration

 

 

 

 

Define the various terms associated with sonography.

 

 

 

 

Calculate critical formulas in order to understand their relationships.

 

 

 

Bioeffects and Safety

2

0

0

 

Define Acoustic Output Quantities including :

      a.  Pressure

i.         Units (MPa, mmHg)

ii.       Peak pressures (compression, rarefaction)

       b.  Power

i.     Units (mW)

       c.   Intensity

i.     Units (mW/cm2, W/cm2)

ii.     Spatial and temporal considerations

iii.      Average and peak intensities

 

 

 

 

Compare and Contrast the Common intensities

a.       SATA

b.       SPTA

c.       SPPA

d.       SPTP

 

 

 

 

Compare and Contrast the methods for determining intensity, power, pressure to include:

a.       Hydrophones

b.       Radiation Force 

 

 

 

 

Compare the Intensity and power values for different operating modes.

 

 

 

 

Discuss acoustic output labeling Standards including

      a.   Thermal Index

i.    TIS

ii.   TIB

iii.  TIC

      b.  Mechanical index

 

 

 

 

Define the concepts of prudent use (ALARA) in reducing acoustic exposure.

 

 

 

 

Discuss the primary Mechanisms of Biologic Effect Production

a.       Cavitation mechanisms: relevant acoustic parameters

b.       Thermal mechanisms: relevant acoustic parameters

 

 

 

 

Distinguish the details of the various experimental biological effect studies to include:

a.       Animal studies

b.       In vitro studies

  1. Epidemiologic studies

 

 

 

 

Recite the key points of the following Guidelines and Regulations regarding ultrasound safety to include:

a.       American Institute of Ultrasound in Medicine (AIUM) statements (e.g., mammalian, epidemiology, in vitro)

b.       National Electrical Manufacturers Association (NEMA)

       c.   Food and Drug Administration (FDA)

 

 

 

 

Discuss the electrical and mechanical hazards of ultrasound examinations to include:

a.    Patient susceptibility to electrical hazard

b.    Equipment components which could present a hazard

 

 

 

Ultrasound Transducers            

3

0

0

 

Define and discuss the concept of the piezoelectric effect.

 

 

 

 

Define Curie point.

 

 

 

 

Compare various piezoelectric materials.

 

 

 

 

Discuss the construction and characteristics of ultrasound transducers to include:

a.       Thickness resonance of crystal

b.       Operating (resonance) frequency

i.         Crystal thickness

ii.       Speed of sound in crystal material

c.       Frequency characteristics (spectrum)

i.         Bandwidth

(1)     Quality factor

(2)     Effect of damping

ii.       Multi-Hertz

(1)     Harmonics

d.       Damping

e.       Matching layer.

 

 

 

 

Discuss sound beam formation .

 

 

 

 

Compare and contrast transducer Arrays and Image appearance based on the following items:

a.       Mechanical and/or electronic construction

b.       Multiple element construction including:

i.          Linear array

ii.       Curved array

iii.      Annular array

iv.      Multi-dimensional array.

c.       Multiple element operation including:

i.     Sequenced

ii.    Phased

iii.   Annular

iv.   Vector

v.        Multi-dimensional.

 

 

 

 

Evaluate transducer care and maintenance.

 

 

 

Pulse Echo Instruments

3

0

0

 

Review the critical factor s affecting Pulse Echo Instruments.

 

 

 

 

Analyze the following dynamic factors in the role of Hemodynamics to include:

  1. Energy gradient
  2. Effects of viscosity, friction, inertia
  3. Pressure/flow relationships
  4. Velocity
  5. Steady flow vs. pulsatile flow
  6. Laminar versus turbulent flow
  7. Effects of stenosis on flow characteristics
  8. Venous resistance
  9. Hydrostatic pressure
  10. Pressure/volume relationship
  11. Effects of respiration (phasicity)

 

 

 

 

Discuss the Doppler Effect as it relates to the sampling of red blood cell movement.

 

 

 

 

Analyze the Doppler equation and the factors influencing the magnitude of the Doppler shift frequency.

 

 

 

 

List the Range of the Doppler shift frequency.

 

 

 

 

Discuss the effects of beam angle, transmitted frequency, flow velocity, and flow direction on Doppler velocities.

 

 

 

 

Compare and contrast Continuous wave and pulsed wave Dopplers listing the advantages and disadvantages of each.

 

 

 

 

Discuss Aliasing and the Nyquist criteria including Range ambiguity.

 

 

 

 

Identify and diagram Doppler Instrumentation including

  1. Receiver
  2. Demodulater
  3. Wall filter for clutter rejection
  4. Directional devices.

 

 

 

 

Define the basic principles and instrumentation associated with Duplex ultrasound and Spectral analysis.

 

 

 

 

Discuss the effect of

  1. Direction
  2. Velocity
  3. Duration
  4. Character
  5. Magnitude
  6. Fast Fourier transform (FFT)

 

 

 

 

Discuss the usefulness of pulsatility and resistive indices.

 

 

 

 

Describe the Basic Principles of  Color Flow Imaging including:

  1. Sampling methods
  2. Display of Doppler information
  3. Reflector direction
  4. Average velocity
  5. Velocity variance
  6. Advantages and limitations

 

 

 

 

Diagram and define Instrumentation issues including

  1. Autocorrelation
  2. Time domain processing
  3. Color field size and frame rate
  4. Ensemble length (packet size, pulse packet)
  5. Line density
  6. Maximum depth
  7. Color maps, assignment, or coding
  8. Hue
  9. Saturation
  10. Luminance (significance, brightness, intensity).

 

 

 

 

Define and analyze Doppler Artifacts

  1. Compare and contrast the properties, advantages and limitations of Color Power (Energy) Mode.

 

 

 

 

 

Suggested Resources

 

Daigle, R (2002). Techniques in Noninvasive Vascular Diagnosis. (2007) Summer Publishing: ISBN:  0-9720653-0-X

Mosby’s Pocket Dictionary of Medicine, Nursing & Health Professions. (5th ed.) Elsevier. ISBN-13: 978-0-323-03943-7

Ridgeway, D. (1998). Introduction to Vascular Scanning. (3rd ed.) Pasadena: Davies Publishing. ISBN: 0-9410-2239-0

Scissons, R. (2003). Physiologic Testing: Techniques and Interpretation. North Kingstown.: Unetixs Corporation

Strandness, E. (2002). Duplex Scanning in Vascular Disorders. (3rd ed.) Philadelphia: Lippincott Publishing. ISBN:  0-7817-2631-X

Taber’s Cyclopedic Dictionary. (20th ed) F. A. Davis. ISBN-13: 978-0-8036-1207-5

Thrush, A. (2005). Peripheral Vascular Ultrasound. (2nd Ed.) Elsevier: Churchill Livingstone. ISBN-13: 978-0-443-07283-3

Zweibel, W., Pellerito, J. (2005), Introduction to Vascular Ultrasonography. (4th ed.) Elsevier: ISBN: 0-7216-6949-2