Hemodynamics
Doppler
Artifacts
QA & Sonographers in the Clinical Setting
Bioeffects
100
Blood flowing through the entrance a vessel, all at the same velocity
What is plug flow
100
A disadvantage of continuous wave doppler based on the fact that the exact location of the moving blood cells cannot be determined
What is range ambiguity
100
This artifact is seen when sound interacts with a rounded reflector
What is edge shadowing
100
The maximum abduction angle a sonographers shoulder should be at to reduce the risk of musculoskeletal injury
What is 30 degrees
100
Other names for transient cavitation
What are inertial and normal
200
Energy lost (or transferred) within the body due to blood cells changing direction
What is inertial loss
200
A dictionary that depicts speed, direction and the way blood flows through vessels (laminar vs. turbulent)
What is variance mode
200
This artifact is seen with weak attenuating reflectors
What is enhancement
200
The quality assurance performance measure that looks at the machines ability to accurately identify pin sizes and location of the horizontal group
What is horizontal calibration
200
According to the AIUM, this key principle must outweigh the risks when utilizing diagnostic ultrasound
What are benefits
300
The form of blood flow that is commonly seen in arteries
What is pulsatile
300
This type of Doppler is subject to aliasing, tells direction, and displays more accurate velocities the more pulses per packet it sends out causing a decrease in the frame rate
What is Color Doppler
300
The speed at which an ultrasound system assumes sound is traveling at
What is 1540m/s
300
A test object that simulates scattering, attenuation, echogenicity, and sounds speed (1540 m/s)
What is a tissue equivalent phantom
300
This study technique searches for a relationship between cause and effect
What is mechanistic approach
400
This number used by practitioners predicts whether flow is laminar or turbulent
What is Reynolds number
400
This digital computer-based technique is used to analyze Color Flow Doppler and is substantially faster to perform than other techniques but less accurate
What is autocorrelation
400
This artifact displays more than 1 reflector on the display
What is crosstalk
400
The study of the interaction between the sonographer, patient and equipment in order to optimize the well being of sonographers in their professional environment
What is ergonomics
400
When considering potential bioeffects, sonographers need to pay closest attention to this during each exam
What is exam duration or exposure time
500
When there is decreased pressure in the thoracic cavity resulting in an increase of blood flow coming from the head and arms
What is inspiration
500
This is the relationship between velocity and the operating frequency
What is inversely related
500
With multipath artifact, where on the image is the reflector is seen in relation to where the reflector should be
What is deeper
500
Ultrasound examination concludes positive appendicitis however the gold standard (CT) shows that the appendix is normal
What is a false positive
500
This tool can measure the bioeffects of intensities at a specific location within a beam
What is a calibrated hydrophone