Artifacts
Which artifact results when the ultrasound system incorrectly assumes all echoes originate from the main beam?
What is Side-lobe or grating-lobe artifact.
Which QA test evaluates the system's ability to detect weak echoes?
What is Sensitivity.
Which ethical principle requires equal treatment regardless of a patient's age, gender, or background?
What is Justice.
Which ultrasound intensity measurement is most closely associated with tissue heating?
What is SPTA (spatial peak temporal average intensity).
Which statistical measure describes the percentage of positive ultrasound examinations that correctly identify disease?
What is Positive predictive value (PPV).
Which artifact occurs when the assumed propagation speed differs from the actual speed of sound in tissue?
What is Speed error artifact.
Which phantom evaluates the ultrasound beam's thickness perpendicular to the imaging plane?
What is Slice-thickness phantom.
A patient withdraws consent halfway through an examination. Which ethical principle takes priority?
What is Autonomy.
Which form of cavitation is associated with bubble collapse and shock-wave production?
what is Transient (inertial) cavitation.
Which statistical measure determines the percentage of all ultrasound examinations that produce correct results, regardless of disease status?
What is Overall accuracy.
A structure appears duplicated on the opposite side of the diaphragm. Which two imaging assumptions are violated?
What is Sound travels in a straight line and sound travels directly to a reflector and back.
Closely spaced pins are resolved at the focus but merge at greater depths. Which type of resolution is being evaluated?
What is Lateral resolution.
Which workplace safety guidelines require employers to assess exposure risks, establish protective procedures, and ensure proper use of personal protective equipment?
What is OSHA guidelines
Two beams have equal peak rarefactional pressure. Which has the higher Mechanical Index: 2 MHz or 8 MHz?
What is 2 MHz, because MI increases as frequency decreases when pressure remains constant.
A screening examination has a sensitivity of 98%. What percentage of patients with disease will receive false negative results?
What is 2%.
Which artifact occurs when sound is redirected by a curved interface, producing a duplicate structure beside the original?
What is Refraction artifact.
During routine phantom testing, identical reflectors at different depths appear with unequal brightness despite appropriate TGC adjustment. Which QA characteristic is being evaluated?
Compensation uniformity.
A sonographer applies excessive transducer pressure to obtain better images despite the patient reporting pain. Which two ethical principles are in conflict?
What is Beneficence and nonmaleficence.
A transducer produces a TI of 1.5. Does this confirm a tissue temperature increase of 1.5°C? Why or Why not?
No. TI estimates potential heating; it does not measure actual tissue temperature.
A screening test identifies 80 patients as positive for disease, but only 60 are confirmed positive by the gold standard. What is the positive predictive value?
What is 75% PPV={60/80} x 100=75%
A deep reflector appears at a shallower depth because its echo arrives after the next pulse is transmitted. Identify the artifact and the parameter that should be decreased.
What is Range ambiguity. Decrease PRF.
Phantom echoes are detected to 14 cm, but two nearby targets appear as one. Is this primarily a sensitivity or resolution problem?
What is Resolution problem. The echoes are detected but cannot be displayed separately.
A competent patient refuses an examination that could benefit their health. Which two ethical principles come into conflict?
What is Autonomy and beneficence.
Two ultrasound beams have the same frequency, but Beam A has a higher peak rarefactional pressure than Beam B. Which beam has a greater likelihood of cavitation, and why?
What is Beam A. Higher peak rarefactional pressure increases the Mechanical Index (MI), indicating a greater likelihood of cavitation.
A test has 80% sensitivity and 95% specificity. Which type of error is more common among patients with disease or without disease: false negatives or false positives?
False negatives have a higher rate within their respective groups: 20% false negative rate versus 5% false positive rate.