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
Grating lobes are most common with which type of transducer technology?
Linear arrays
Two small cysts, positioned perpendicular to the main axis of a sound beam, are 2.4 mm apart. What determines weather they appear as two distinct images on the systems display?
Beam width
True or false
Artifacts are likely to appear when the dimensions of the sound beam area are larger than the dimensions of the reflectors in the body
True
True or false
All artifacts are errors in imaging that do not represent the true anatomy of the imaged organ. Therefore, they are all undesirable and should be eliminated if possible
False
Who is responsible for implementing a quality assurance action plan?
Sonographer
True or false
Flow phantoms are the devices of choice for evaluating soft tissue?
False
Two forms of sensitivity are
Normal and maximum
An acoustic standoff may be used to image
Superficial structures
Axial resolution is evaluated by scanning
Sets of successively closer spaced pins
Quality assurance is the routine evaluation of an ultrasound system to guarantee optimal image quality. This should be preformed ______
Periodically
There are 4 requirements for a quality assurance program. One of the requirements are:
Repairs
A proper method for the quality assurance program is
Image in an identical environment
The tissue equivalent phantom will contain which structures
Nylon strings, structures that mimic hollow cysts
True or false
Normal sensitivity should vary from one routine evaluation to the next
False
Which frequency transducers have a thinner dead zone?
Higher
The accuracy of reflector depth positioning in A-mode, M-mode, B-mode, and 2-D imaging is called
Depth calibration
The patient has the capacity to act intentionally, with understanding, and with free will, is
Informed consent
Informed consent generally includes the following:
Risks, benefits, and uncertainties related to each alternative
When can a patient withdraw consent for the procedure?
At any time
What should the sonographer do when first meeting the patient?
Introduce yourself
True or false
As a sonographer, you have the right to tell the patient what you think their exam findings are before the dr comes into the room
False
True or false
It is best to continue scanning the same type of studies all day and to also add as many patients into the schedule for the best ergonomics on the sonographer
False
True or false
Gloves should only be worn when you know that you will be handling blood from someone who has something like HIV. You will only need to wash your hands after you scan 5 patients or if you get them dirty
False
True or false
Workers should not engage in tasks or activities that will potentially put them at risk of exposure of being harmed
True
