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System Operation & Components

  1. Computed Tomography, or CT has also been commonly referred to as what?

  2. A. Computerized Axial Tomography
    B. CAT
    C. Neither A or B
    D. Both A & B
  3. T/F: The electronic signals sent to the table, gantry and high voltage generator must be converted into an analog waveform.

  4. Where does the Technologist initiate instructional commands?

  5. A. At the Gantry
    B. Into the PACS Server
    C. From the CT System Console
    D. Standing on the patients right side
  6. What does the Scan Controller do?

  7. Answer

  8. What type of information can be entered at the CT Console?

  9. A. Imaging Parameters
    B. Post-processing Techniques
    C. Filming and Archiving instructions
    D. All of the above
  10. Each command is shuttled through the _____________, as it is __________ into the system's machine language.

  11. A. gantry, placed
    B. host computer, translated
    C. ER Doctor, checked
    D. Hospital, translated
  12. Where is each command sent to after it is translated into the system's machine language?

  13. A. The Scan Controller
    B. The A-to-D converter
    C. The high voltage generator
    D. The D-to-A converter
  14. What is another name for "Analog" waveform?

  15. Answer

  16. The gantry contains some of the most important components of the scanner including...

  17. A. The CT x-ray Tube
    B. The Detectors
    C. The Scan Controller
    D. A & B only
  18. T/F: The conversion of electronic signal output from the scan controller into analog waveform is carried out by the A-to-D Converter.

  19. The ______________ is necessary to produce the high voltage potential that exists between the cathode and the anode.

  20. Answer

  21. The attenuation information measured by the detector elements is converted into ____ electrical signals that must be passed through a/an _________.

  22. A. digital, filter
    B. analog, high voltage generator
    C. tiny, amplifier
    D. digital, amplifier
  23. After the tiny electrical signals are amplified they are sampled via the _____________.

  24. Answer

  25. Computed Tomography, or CT, has been commonly called _______________ _______ ________________ or ______________ in the past.

  26. Answer

  27. Where are the instructional commands entered by the technologist?

  28. Answer

  29. List five types of information/instructions that are entered at the CT System Console.

  30. Answer

  31. What CT System Component translates each command as it is entered into the systems machine language before passing it on to the Scan Controller?

  32. Answer

  33. What does the scan controller do?

  34. Answer

  35. Which System Components operate using analog waveform?

  36. Answer

  37. What is another name for analog waveform?

  38. Answer

  39. What CT System Component is responsible for converting the digital signal into an analog form?

  40. Answer

  41. What does DAC stand for?

  42. Answer

  43. What are the two most notable components located in the gantry?

  44. Answer

  45. What CT System Component is necessary to produce the high voltage potential that exists between the cathode and the anode?

  46. Answer

  47. What gantry component collects the attenuation information?

  48. Answer

  49. What do the detector elements do?

  50. Answer

  51. Where is the tiny electrical signal output from the detector elements sent?

  52. Answer

  53. In what electrical form does the amplifier output its signal/information?

  54. Answer

  55. Where does the analog signal go to after it leaves the amplifier component?

  56. Answer

  57. Where does the analog signal go to after it leaves the Sample-and-Hold Component?

  58. Answer

  59. Where is the data stored after it leaves the DAC?

  60. Answer

  61. In which system component is data calculated into an image?

  62. Answer

  63. Where does the calculated image go after it leaves the Array Processor and what for?

  64. Answer

  65. When was the 1st CT System commercially introduced for general clinical use?

  66. Answer

  67. How many Generations of CT Systems are there?

  68. Answer

  69. First Generation CT Systems generated a thin, focused x-ray beam called what?

  70. Answer

  71. How many detectors were incorporated in the 1st Generation CT Systems?

  72. Answer

  73. What was it called when the Tube/Detector configuration in a 1st Generation Scanner scanned across the patient’s body in a linear path before rotating and repeating?

  74. Answer

  75. In a 1st generation scanner, what did you call the series of measurements that was collected as the tube/detector assembly translated across the patient?

  76. Answer

  77. What is the 1st generation definition of a Projection?

  78. Answer

  79. 1st Generation: What happens next after a complete translation from one side of the patient to the other?

  80. Answer

  81. How many different projections were needed in a 1st generation system in order to construct and image?

  82. Answer

  83. What was the shortest possible scan time per image with a 1st Generation system?

  84. Answer

  85. Since 1st generation scanners were so slow, imaging was limited to what part of the body and why?

  86. Answer

  87. List four key aspects of 1st generation CT Scanners.

  88. Answer

  89. 2nd generation CT Systems used an x-ray tube that produced an x-ray beam that had a shape similar to a/an ____________________.

  90. Answer

  91. 2nd generation systems are referred to as having _________________ Geometry.

  92. Answer

  93. 2nd generation CT Systems contain a/an _______ of detectors referred to as a/an ___________________.

  94. Answer

  95. About how many detectors comprised the detector array in 2nd generation scanners?

  96. Answer

  97. What was the purpose of the added detectors (detector array) and the fan beam geometry in the 2nd generation design?

  98. Answer

  99. How much faster could a 2nd generation scanner collect the required data compared to a 1st generation scanner?

  100. Answer

  101. T/F: In regards to 2nd generation CT Systems, the tube/detector assembly still translated across the patient during the collection of a “projection” of data.

  102. After a “projection” of data is obtained in a 2nd generation CT System, the tube/detector rotates typically ____________ covering an arc of __________ around the patient.

  103. Answer

  104. What was the scan time for a single image in a 2nd generation scanner?

  105. Answer

  106. What single aspect of 2nd generation scanners led to applications outside the head?

  107. Answer

  108. What were the 2 most important features of 2nd generation scanners which quickly made 1st generation systems obsolete?

  109. Answer

  110. List the four key aspects of 2nd generation CT Systems.

  111. Answer

  112. When were 3rd generation systems first introduced?

  113. Answer

  114. Most CT Scanners made today still apply similar technologies as those incorporated in which generation of CT Systems?

  115. Answer

  116. 3rd generation systems incorporate what type of beam geometry?

  117. Answer

  118. The tube/detector array in a 3rd generation system no longer ____________ as in 1st and 2nd generation systems but simply __________ around the patient.

  119. Answer

  120. What was the major difference in the configuration between 2nd and 3rd generation CT systems?

  121. Answer

  122. Why was the curved detector array contained in 3rd generation CT systems an improvement over 1st and 2nd generation designs?

  123. Answer

  124. Most scanners today are based on ___________________ technology.

  125. Answer

  126. How many detectors are contained in a 3rd generation system detector array?

  127. Answer

  128. The term “scan” slightly changed meaning with the introduction of 3rd generation systems. Why?

  129. Answer

  130. What is today’s definition of a “scan”?

  131. Answer

  132. How fast can a 3rd generation system acquire the data for one image?

  133. Answer

  134. List the four key aspects of a 3rd generation CT system.

  135. Answer

  136. Why were 4th generation systems developed?

  137. Answer

  138. What is the beam geometry of a 4th generation system?

  139. Answer

  140. Describe the detector arrangement in a 4th generation CT system.

  141. Answer

  142. What does nutate mean?

  143. Answer

  144. T/F: Many more detectors are required in 3rd generation scanners than 4th generation scanners.

  145. Answer

  146. T/F: 4th generation systems did not necessarily represent a design which was more advanced than 3rd generation systems or that offered improved clinical benefits.

  147. T/F: 3rd and 4th generation systems use different approaches to achieve similar results.

  148. T/F: Today there are very few scanners that use 4th generation technology.

  149. List the four key aspects of 4th generation CT systems.

  150. Answer

  151. T/F: In the early days of 3rd generation systems, the high voltage generator was large and heavy and was safely fastened to the floor in the exam room.

  152. In the days before continuous rotation scanners, what transferred the high voltage from the generator to the x-ray tube?

  153. Answer

  154. In the early days of 3rd generation scanners, before the invention of continuous rotation scanners, why was it necessary to stop the gantry frame from rotating at the end of every scan and then reverse the direction of the gantry frame’s rotation for the next scan?

  155. Answer

  156. Why were continuous rotation scanners introduced?

  157. Answer

  158. Most continuous rotation scanners use ______________ technology.

  159. Answer

  160. What is the slip Ring?

  161. Answer

  162. Why was slip ring technology such an improvement over existing technology?

  163. Answer

  164. What was the single most important advancement that led to the development of helical imaging?

  165. Answer

  166. What is another name for helical imaging?

  167. Answer

  168. What is another name for conventional scanning?

  169. Answer

  170. Did Continuous Rotation and Multi-row Detector scanners come out at about the same time?

  171. Answer

  172. What are the only two ways to cover anatomy faster in a helical study with a single row detector scanner?

  173. Answer

  174. What does MDCT stand for?

  175. Answer

  176. What are other names for MDCT?

  177. Answer

  178. What type of architecture do MDCT scanners have?

  179. Answer

  180. What are the three things that are transferred by the slip ring?

  181. Answer

  182. How many detectors are contained in a single detector array of a 3rd generation system?

  183. Answer

  184. List the benefits of MDCT.

  185. Answer

  186. What does EBCT stand for?

  187. Answer

  188. When was EBCT originally designed?

  189. Answer

  190. T/F: EBCT does not use an x-ray tube.

  191. How does EBCT work?

  192. Answer

  193. What is the fastest CT on the market?

  194. Answer

  195. How long does one “rotation” take on an EBCT scanner?

  196. Answer

  197. The speed of EBCT makes it well suited for doing what?

  198. Answer