Final-chapter 21-23 Flashcards
Enhancement artifacts appear as a ______
Hyperechoic region
Shadows appear when attenuation is too _____?
High
Structures with equal echo brightness are described as?
Isoechoic
Focal enhancement is a special form of enchantment in which a ______ region of an image appears brighter than tissue at other depths
Side-to-side
What are the characteristics of a medium that produces comet tail artifacts?
Strong reflectors, closely spaced, high propagation speed
When enhancement occurs, where does it appear on the image?
Deeper than a weak attenuator
What is the noise resulting from the constructive and destructive interference of small sound wavelets?
Acoustic speckle
True or false
Spatial resolution is related to the overall detail in an image
True
Portions of an image that are not as bright as surrounding tissues are
Hypoechoic
Characteristics of reverberation are
Appear in multiples
Which artifacts is created when closely spaced reverberations merge
Comet tail
On a mirror image artifact, does the artifact appear DEEPER or SHALLOWER than the true reflector?
Deeper
Focal banding has the same appearance as an
Incorrect TGC setting
True or false
High pixel density declines spatial resolution
False
If an ultrasound pulse travels through a large mass in the body at a speed of 1.2 mm/us, what happens to the position of all echoes produced from reflectors shallower than the mass?
They are likely to be placed at the correct depth
What types of artifact causes a reflection to be placed at an incorrect depth?
Range ambiguity