Understanding Ultrasound Physics - SPI
Exam Review - ARTIFACTS
Which of the following is not a potential cause of artifact and diagnostic imaging?
A. Operator error
B. equipment malfunction
C. Patient motion
D. Ultrasound physics
E. none of the above - ✔️✔️E. none of the above
The four choices, A through D, represent the primary explanations of artifacts commonly
seen in diagnostic ultrasound.
What is the meaning of the term "analysis" in the context of spectral analysis of Doppler
signals?
A. Building a sophisticated signal from components
B. building a simplified signal from components
C. identifying the building blocks or components of a complex signal
D. measuring a complex signal then modifying its information content - ✔️✔️C.
identifying the building blocks or components of a complex signal
The term analysis defines the act of scrutinizing an object to determine what individual
components are incorporated within it. In Doppler analysis, the complex signal is broken
down into its more basic ingredients.
The analysis of Doppler Spectra using _______ is most accurate.
A. Zero crossing detectors
B. fast fourier transforms
C. time interval histograms
D. chirp Z transforms - ✔️✔️B. fast fourier transforms
The fast fourier transform, or FFT, is the most accurate spectral analysis technique.
Techniques such as zero crossing, time interval histograms, and chirp Z were initially
used to assess Doppler Spectra, but are now obsolete. Fast fourier analysis became
popular when computers were incorporated into ultrasound systems.
Spectral analysis of color flow Doppler is most commonly performed by which of the
following techniques?
A. Zero crossing detectors
, B. fast fourier transforms
C. autocorrelation
D. Chirp Z transforms - ✔️✔️C. autocorrelation
Autocorrelation is a technique of choice for spectral analysis of color Doppler. Although
the most accurate technique is the FFT, autocorrelation is better suited to process the
enormous amount of data acquired in a color Doppler study.
While using a linear sequential array transducer during a color Doppler exam, the shape
of the grayscale image is most often _______, Whereas the shape of the color Doppler
portion of the image is _______.
A. rectangular, parallelogram
B. rectangular, sector
C. sector, trapezoid
D. square, rectangular - ✔️✔️A. rectangular, parallelogram
The shape of a grayscale image using a linear sequential array is rectangular. However,
the sound beams used for Doppler are steered at an angle, creating a parallelogram
shaped region.
Acoustic artifacts include: (more than one answer may be correct.)
A. images of reflectors in an inappropriate position
B. Images of reflectors with improper shape
C. images of reflectors with incorrect brightness
D. images that do not correspond to anatomical structures - ✔️✔️A. images of
reflectors in an inappropriate position
B. Images of reflectors with improper shape
C. images of reflectors with incorrect brightness
D. images that do not correspond to anatomical structures
An artifact is an error in imaging. All of the choices indicate a type of error, and
therefore, are artifacts.
Ultrasound systems are designed to automatically _______ .
A. display similar structures with equal brightness, regardless of depth
B. position structures at the correct depth, regardless of the medium
C. display all reflections on a line corresponding to the main axis of the sound beam,
regardless of refraction
Exam Review - ARTIFACTS
Which of the following is not a potential cause of artifact and diagnostic imaging?
A. Operator error
B. equipment malfunction
C. Patient motion
D. Ultrasound physics
E. none of the above - ✔️✔️E. none of the above
The four choices, A through D, represent the primary explanations of artifacts commonly
seen in diagnostic ultrasound.
What is the meaning of the term "analysis" in the context of spectral analysis of Doppler
signals?
A. Building a sophisticated signal from components
B. building a simplified signal from components
C. identifying the building blocks or components of a complex signal
D. measuring a complex signal then modifying its information content - ✔️✔️C.
identifying the building blocks or components of a complex signal
The term analysis defines the act of scrutinizing an object to determine what individual
components are incorporated within it. In Doppler analysis, the complex signal is broken
down into its more basic ingredients.
The analysis of Doppler Spectra using _______ is most accurate.
A. Zero crossing detectors
B. fast fourier transforms
C. time interval histograms
D. chirp Z transforms - ✔️✔️B. fast fourier transforms
The fast fourier transform, or FFT, is the most accurate spectral analysis technique.
Techniques such as zero crossing, time interval histograms, and chirp Z were initially
used to assess Doppler Spectra, but are now obsolete. Fast fourier analysis became
popular when computers were incorporated into ultrasound systems.
Spectral analysis of color flow Doppler is most commonly performed by which of the
following techniques?
A. Zero crossing detectors
, B. fast fourier transforms
C. autocorrelation
D. Chirp Z transforms - ✔️✔️C. autocorrelation
Autocorrelation is a technique of choice for spectral analysis of color Doppler. Although
the most accurate technique is the FFT, autocorrelation is better suited to process the
enormous amount of data acquired in a color Doppler study.
While using a linear sequential array transducer during a color Doppler exam, the shape
of the grayscale image is most often _______, Whereas the shape of the color Doppler
portion of the image is _______.
A. rectangular, parallelogram
B. rectangular, sector
C. sector, trapezoid
D. square, rectangular - ✔️✔️A. rectangular, parallelogram
The shape of a grayscale image using a linear sequential array is rectangular. However,
the sound beams used for Doppler are steered at an angle, creating a parallelogram
shaped region.
Acoustic artifacts include: (more than one answer may be correct.)
A. images of reflectors in an inappropriate position
B. Images of reflectors with improper shape
C. images of reflectors with incorrect brightness
D. images that do not correspond to anatomical structures - ✔️✔️A. images of
reflectors in an inappropriate position
B. Images of reflectors with improper shape
C. images of reflectors with incorrect brightness
D. images that do not correspond to anatomical structures
An artifact is an error in imaging. All of the choices indicate a type of error, and
therefore, are artifacts.
Ultrasound systems are designed to automatically _______ .
A. display similar structures with equal brightness, regardless of depth
B. position structures at the correct depth, regardless of the medium
C. display all reflections on a line corresponding to the main axis of the sound beam,
regardless of refraction
