Chapter 7 Flashcards
In soft tissue, a temperature rise is considered significant once it exceeds ____.
a. 2 c
b. 4 c
c. 2 f
d. 4 f
a. 2 c
Bioeffects have not been observed in experimental animals intensities below _______.
a. 1 mW/cm^2 spatial peak-temporal average (SPTA)
b. 10 mW/cm^2 SPTA
c. 1 mW/cm^2 spatial peak-temporal peak (SPTP)
d. 10 mW/cm^2 SPTP
a. 1 mW/cm^2 spatial peak-temporal average (SPTA)
Which of the following describes cavitation?
a. Flow in an absorbing fluid
b. Conversion of ultrasound to heat
c. Temperature rise as ultrasound propagates through tissue
d. Production and behavior of bubbles in a liquid medium
d. Production and behavior of bubbles in a liquid medium.
The piezoelectric material commonly used in hydrophones is ______.
a. PVD
b. PVDF
c. PZT
d. PZTF
b. PVDF
Which of the following is not assessed with a tissue-equivalent (TE) phantom?
a. Penetration
b. Beam width
c. Dynamic range.
d. TGC operation
b. Beam width
Tissue-equivalent phantoms are filled with a substance containing _______.
a. water
b. quartz
c. silicone
d. graphite
d. graphite
No bioeffects have been observed in mammalian tissues that contained well-defined gas bodies at peak rare factional pressure valves (MPa) of less than _____.
a. 0.4
b. 0.2
c. 0.3
d. 0.1
a. 0.4
Plant studies are useful primarily for _____.
a. identifying focal lesion production
b. understanding cavitational effects in living tissue
c. determining conditions under which thermal effects occur
d. determining conditions under which non thermal effects occur
b. understanding cavitational effects in living tissue
Which of the following cannot be measured or calculated by a hydrophone
a. Period
b. Amplitude
c. Impedance
d. Pulse duration
c. Impedance
The extent of temperature rise produced depends on
a. intensity and frequency
b. type of tissue and intensity
c. penetration depth and frequency
d. number of focal zones and intensity
a. intensity and frequency
Which of the following pulsed imaging techniques demonstrates the highest acoustic output?
a. Gray-scale
b. Motion mode
c. Color Doppler
d. Spectral Doppler
d. Spectral Doppler
No bioeffects have been observed in mammalian tissues at mechanical index values of less than _____.
a. 0.4
b. 0.3
c. 0.2
d. 0.1
a. 0.4
Attenuation is soft tissue is due primarily to ____.
a. refraction
b. absorption
c. reflection
d. transmission
b. absorption
Test objects evaluate _____.
a. amplitude
b. detail resolution
c. dynamic range
d. temporal resolution
b. detail resolution
The American College of Radiology (ACR) Ultrasound Accreditation Program requires at least ______ testing for instrument quality control.
a. semimonthly
b. monthly
c. semiannual
d. annual
c.semiannual
