ARDMS RVT URR QA, SAFETY & SPI
QUESTIONS WITH 100% CORRECT
ANSWERS { GRADED A+}
Which the following describes why there is no aliasing on CW doppler?
A. the PW transducer uses a single element and the CW transducer uses
two elements
B. CW doppler does not require a sample volume to produce a doppler
waveform
C. CW doppler does not require beam steering to produce a doppler
waveform
D. CW probes are always lower frequency than PW probes - ✔✔A. the
PW tx uses a single element and the CW tx uses two elements
,CW doppler uses separate elements for sending and receiving the sound
waves. This allows for doppler evaluation without depth limitations.
According to the Appropriate Use Criteria, which of the following is an
inappropriate indication for a duplex exam on a hemodialysis fistula?
A. inability to cannulate at dialysis
B. ipsilateral arm swelling
C. palpable thrill at the fistula site
D. 1 month follow up baseline exam post-intervention - ✔✔C. palpable
thrill at fistula site
Hemodialysis fistulas and grafts will normally demonstrate a thrill over
the connection site in the arm. Absence of the thrill ca indicate an
occlusion of the fistula/graft.
If a carotid doppler exam was performed last year with a doppler angle
of 45-degrees and the current exam was performed with a 60-degree
angle. Assuming there has been no change in the level of stenosis, how
will this affect the exam?
,A. velocities will be increased compared to last years exam
B. no change because the ultrasound system is programmed to always
assume a 60-degree angle is used for each exam and uses this angle in
the doppler equation
C. no change because the ultrasound system is programmed to always
assume a 0-degree angle is used for each exam and uses this angle in the
doppler equation
D. velocities will be reduces compared to last years exam - ✔✔A.
velocities will be increased compared to last years exam
As the cursor angle increases, the angle between the bean and the flow
decreases. As the angle between the bean and the flow decreases, the
doppler shift increases (the more aligned the cursor is to the flow
direction, the higher the doppler shift). EX: increasing the cursor angle
from 45 to 60 degrees = decreased angle between the bean and the flow
= increased doppler shift and velocity.
, EX: decreasing the cursor angle from60 to 45 degrees = increased angle
between the beam and the flow = decreased doppler shift and velocity.
Overestimating the angle between the bean and the blood flow =
overestimated flow velocity
Underestimating the angle between the beam and the blood flow =
underestimated flow velocity.
if new research shows that the minimum velocity criteria used to
diagnose >60% renal artery stenosis
is actually 225cm/s, not 180cm/s, how will this affect the negative
predictive value of the exam?
A. increase by 4.5%
B. decrease by 4.5%
C. no effect on the negative predictive value, only affects accuracy
D. decrease will vary with patient population - ✔✔D. decrease will
vary with patient population
QUESTIONS WITH 100% CORRECT
ANSWERS { GRADED A+}
Which the following describes why there is no aliasing on CW doppler?
A. the PW transducer uses a single element and the CW transducer uses
two elements
B. CW doppler does not require a sample volume to produce a doppler
waveform
C. CW doppler does not require beam steering to produce a doppler
waveform
D. CW probes are always lower frequency than PW probes - ✔✔A. the
PW tx uses a single element and the CW tx uses two elements
,CW doppler uses separate elements for sending and receiving the sound
waves. This allows for doppler evaluation without depth limitations.
According to the Appropriate Use Criteria, which of the following is an
inappropriate indication for a duplex exam on a hemodialysis fistula?
A. inability to cannulate at dialysis
B. ipsilateral arm swelling
C. palpable thrill at the fistula site
D. 1 month follow up baseline exam post-intervention - ✔✔C. palpable
thrill at fistula site
Hemodialysis fistulas and grafts will normally demonstrate a thrill over
the connection site in the arm. Absence of the thrill ca indicate an
occlusion of the fistula/graft.
If a carotid doppler exam was performed last year with a doppler angle
of 45-degrees and the current exam was performed with a 60-degree
angle. Assuming there has been no change in the level of stenosis, how
will this affect the exam?
,A. velocities will be increased compared to last years exam
B. no change because the ultrasound system is programmed to always
assume a 60-degree angle is used for each exam and uses this angle in
the doppler equation
C. no change because the ultrasound system is programmed to always
assume a 0-degree angle is used for each exam and uses this angle in the
doppler equation
D. velocities will be reduces compared to last years exam - ✔✔A.
velocities will be increased compared to last years exam
As the cursor angle increases, the angle between the bean and the flow
decreases. As the angle between the bean and the flow decreases, the
doppler shift increases (the more aligned the cursor is to the flow
direction, the higher the doppler shift). EX: increasing the cursor angle
from 45 to 60 degrees = decreased angle between the bean and the flow
= increased doppler shift and velocity.
, EX: decreasing the cursor angle from60 to 45 degrees = increased angle
between the beam and the flow = decreased doppler shift and velocity.
Overestimating the angle between the bean and the blood flow =
overestimated flow velocity
Underestimating the angle between the beam and the blood flow =
underestimated flow velocity.
if new research shows that the minimum velocity criteria used to
diagnose >60% renal artery stenosis
is actually 225cm/s, not 180cm/s, how will this affect the negative
predictive value of the exam?
A. increase by 4.5%
B. decrease by 4.5%
C. no effect on the negative predictive value, only affects accuracy
D. decrease will vary with patient population - ✔✔D. decrease will
vary with patient population
