Appendix : Developing a Test Taking Strategy
7
Question Type:
Peek
Keywords:
safety, BEST (Implies more than one choice
may be correct!)
Central concept:
Patient safety depends on minimizing risk
by limiting transmit power, minimizing
scan times, and not performing needless
scans.
By peeking, we know that this question is
asking how the
instrument controls should be set. In-
creasing gain does not increase risk to the
patient, whereas increasing output power
does.
Now find the choice which matches your answer.
Choice A is true.
Check other choices to be certain there
is no better choice.
Choice B
is not consistent with minimizing risk because
of high transmit power.
Choice C
is ridiculous!
Choice D
is generally true, but states nothing about the
transmit power.
Choice E
is also not consistent withminimizing risk,since
there is a high output power.
(Note: Scanning a difficult patient will force you to use higher transmit
power and high receiver gain. Since we are not given any informa-
tion which suggests a very difficult patient, and none of the other
answers better relate to the question of patient safety, the answer is
clearly choice A.)
5.
Which one of the following instruments is a component that
stores digital echo signal information?
A. Demodulator
B. Receiver
C. Video monitor
D. Logarithmic amplifier
E. Scan converter
Question Type:
No Look
Keywords:
stores, digital, signal
Central concept:
There are effectively two instruments for
storing digital data: the scan converter, or
an external digital storage device such as an
optical disk or floppy disk.
Now find the choice which matches your answer.
Choice E is a direct match!
6.
The dynamic range of the receiver of an ultrasound instrument
refers to the
A. ability of the receiver to track a rapidly moving
structure.
B. range of echo signal frequencies that can be processed
without distortion.
C. speed with which the receiver recovers following the
excitation pulse to the transducer.
D. depth range in tissue over whichmoving echoes can be
received.
E. range of echo signal amplitudes that can be processed
without distortion.
Question Type:
No Look
Keywords:
dynamic range, receiver
Central concept:
The term dynamic range refers to a ratio of
a maximum to a minimum of any quantity.
You can talk about the dynamic range of an
eye, the video display, a receiver or a bank
account balance. It is critical to note the key
word “receiver”. The dynamic range of the
receiver is the ratio of the maximum signal
(or strongest signal) to the minimum signal
(weakest signal) the receiver can faithfully
detect.
Now find the choice which matches your answer.
Choice A is completely unrelated. This distracter is for
those people who have not learned the definition
of dynamic range and guess based on the alter-
nate meaning of the word dynamic as meaning
movement.
Choice B
is a tough distracter. Although it is possible to
speak of the receiver frequency input dynamic
range, it is not common. We would generally
refer to this as the receiver bandwidth.
Choice C
is completely unrelated. The time to recover from
an excitation pulse is called the ring down, and
creates a “dead zone.”
Choice D
is just nonsense.
Choice E is true.
A distorted signal has been corrupted so
that it no longer accurately represents the actual
signal. Stating the “range of echo signal ampli-
tudes that can be processed without distortion,”
is equivalent to saying“the ratio of the maximum
to minimum signals which can be received ac-
curately, or faithfully detected.”
