SPI Practice Questions Answers A

SPI Practice Questions Answers A Which of these terms means 'many gray shades'? A wide dynamic range B bistable C high contrast D highly compressed signal E few choices ️A wide dynamic range Which of the following will result in the highest mechanical index? A high intensity and high frequency B low frequency and high signal amplitude C low intensity and low frequency D high frequency and low power ️B low frequency and high signal amplitude mechanical index is inversely related to frequency and directly related to amplitude Which of the following steps is performed just prior to storage of image data in a digital scan converter? A demodulation B rectification C A-to-D conversion D D-to-A conversion E read magnification ️C A-to-D conversion Analog to digital conversion occurs just prior to storage of the image in the digital scan converter. All of the following correctly describe dynamic range EXCEPT: A relative B comparison C logarhythmic D absolute E ration ️D absolute Dynamic range is not an absolute measurement. It is a relative measurement that compares two values. Which of the following lists is in decreasing order? A kilo, hecto, deci, milli, micro, nano B deci, deca, nano, milli, mega, hecto C mega, macro, milli, nano, pico D nano, micro, milli, kilo E mega, nano, deci, deca, micro ️A kilo, hecto, deci, milli, micro, nano Which component of an ultrasound system exposes the patient to the greatest risk? A pulser B transducer C beam former D high voltage display tube E spark autoregulator ️B transducer Which of the following best describes a sound beam? A electrical impulses B a collection of mechanical vibration in a form of compressions and rarefactions C electromechanical variations D ionic vibrations E a wave that man can hear ️B a collection of mechanical vibration in a form of compressions and rarefactions All of the following artifacts place the erroneous reflection at the same depth as the true reflector EXCEPT: A grating lobe B side lobe C refraction D mirror image ️D mirror image artifact appears at a deeper depth than the true reflector Which of these choices has the greatest effect upon depth of view? A spatial pulse length B pulse repetition period C transducer output D acoustic impedance E pulse duration ️B pulse repetition period The PRP determines imaging depth. Longer PRPs are with deep imaging, while shorter PRPs are associated with shallow imaging. Which of these terms does not belong with the others? A high duty factor B high PRF C shallow imaging D short pulse repetition period E short pulse duration ️E short pulse duration All of the other terms are consistent with shallow imaging. The pulse duration is unrelated to imaging depth. Which of the following statement about Doppler is most correct? A non-directional Doppler uses phase-singular processing, while bi-directional Doppler uses phase quadrature processing B non-directional Doppler uses FFT processing, while bi-directional Doppler uses Nyquist processing C non-directional Doppler uses autocorrelation processing, while bi-directional Doppler uses phase quadrature processing D non-directional Doppler uses non-coherent processing, while bi-directional Doppler uses phas