Digital: Ch 6 question with correct answers 2023

Digital: Ch 6 question with correct answers 2023A highly efficient indirect conversion system that takes up less fill space than CCDs is known as a ______. 1 Charge-coupled device 2 Field-effect transistor 3 CMOS 4 Thin-field transistor 3.) CMOS pg. 76: this system is highly efficient and takes up less fill space than CCDs Which of the following flat-panel detector technologies was developed by NASA? 1 Charge-coupled device 2 Field-effect transistor 3 CMOS 4 Thin-field transistor 3.) CMOS pg. 76: developed by NASA, complimentary metal oxide semiconductor (CMOS) systems... Which statement best describes a charge-coupled device (CCD)? 1 It is the oldest direct conversion technology that is still in use today. 2 It is the oldest direct conversion technology with limited use today. 3 It is the oldest indirect conversion technology that is no longer used in medical imaging. 4 It is the oldest indirect conversion technology used in a variety of image capture applications. 4.) It is the oldest indirect conversion technology used in a variety of image capture applications. pg. 73: the oldest indirect-conversion digital radiography systems used charge-coupled devices (CCDs) to acquire the digital image. These devices are still being used today in a variety of image capture applications. A device that acts like a camera in an indirect conversion detector is known as a: 1 CCD. 2 field-effect transistor. 3 CMOS 4 thin-field transistor. 1.) CCD The components that focus the signal from the scintillators to the CCD are called: 1 detector elements. 2 capacitors. 3 fiber optics. 4 analog-digital converters. 3) fiber optics. Pg. 75: fiber optics are used to focus light onto the CCD chip. Which statement best describes a capacitor? 1 It converts x-ray photons to light. 2 It converts light to an electrical charge and stores it. 3 It converts x-ray photons to light and stores it. 4 It stores light and converts it from an analog to a digital signal. 2.) It converts light to an electrical charge and stores it Pg. 73: during the transmission process, the lenses (fiber optics) reduce the size of the projected visible light image and transfer the image to one or more small capacitors that convert the light into an electrical charge. Which of the following statements about scintillators is true? 1 All scintillators absorb the same amount of x-ray photons. 2 The amount of x-rays absorbed depends on the type of scintillator. 3 Structured phosphors produce more light spread. 4 Unstructured phosphors are more efficient. 2) The amount of x-rays absorbed depends on the type of scintillator. Pg. 75: the type of scintillator and the way it is constructed will determine how much of the incident x-ray photons are absorbed, how much light is produced, and the wavelength or color of the light. Unstructured phosphors produce more light, thereby decreasing the efficiency of the detector. Detector elements are formed by voltage gates that _____ at readout to _____ the flow of electrons. 1 close; allow 2 open; allow 3 close; stop 4 open; stop 2.) open; allow pg. 74: the dels (detector elements) are formed by voltage gates that, at readout, are opened and closed like gates to allow the flow of electrons. The readout process requires that _______ and _______. 1 electrons flow freely when the gates are open; voltage stays consistent 2 the flow of electrons is timed; voltage stays consistent 3 electrons flow freely when the gates are open; multiple voltage changes occur 4 the flow of electrons is timed; multiple voltage changes occur 4.) the flow of electrons is timed; multiple voltage changes occur pg. 74: the readout process requires that the movement of the electrons is timed, and multiple voltage changes occur. The most common types of noise that affect image quality include all of the following except: 1 quantum noise. 2 statistical noise. 3 "dark" current noise. 4 amplification noise. 1.) quantum noise. pg. 75: there are several types of noise associated with CCD technology; statistical noise, “dark” current noise, and amplification noise. Clinical applications for CCDs include all of the following except: 1 digital fluoroscopy. 2 computed tomography fluoroscopy. 3 digital mammography. 4 general radiography. 2.) computed tomography fluoroscopy. pg. 76: CCDs are used in several applications in radiology including digital fluoroscopy, stereotactic breast biopsy, digital mammography, and general radiography. When compared with a CMOS, CCDs: 1 are less light sensitive. 2 are more susceptible to noise. 3 use more than 100 times the power. 4 are inexpensive to manufacture. 3.) use more than 100 times the power. pg. 77: CCDs may use as much as 110 times the power that CMOS. CMOS use very little power CMOS are more sensitive to noise CMOS are less sensitive to light CMOS are less expensive to manufacture The most popular base material used in integrated circuits is: 1 selenium. 2 sulfur. 3 silicon. 4 tellurium. 3.) silicon pg. 76: silicone is the most popular semiconducting material, and is the base material of most integrated circuits. Demagnification is: 1 reducing the phosphor output image to the size of the active area of the CCD. 2 reducing the field size of the CCD detector. 3 reducing the amount of light spread from the scintillator. 4 none of the above. 1.) reducing the phosphor output image to the size of the active area of the CCD A detector in which each pixel has its own amplifier is known as a: 1 CCD. 2 field-effect transistor. 3 CMOS. 4 thin-field transistor 3.) CMOS. pg. 76: CMOS - each pixel has its own amplifier A highly efficient indirect conversion system that takes up less fill space than CCDs is known as a(n): 1 analog to digital converter. 2 field-effect transistor. 3 CMOS. 4 thin-field transistor. 3.) CMOS