CT Module 1 Test

X-rays are produced whenever fast-moving electrons collide with any form of matter because: 1.) The electron splits into two x-ray photons of equal energy upon impact with the matter. 2.) The electron loses kinetic energy when is converted into the emission of an x-ray photon 3.) The electron it collides with into an x-ray photon 4.) All the above

2.) The electron loses kinetic energy which is converted into the emission of an x-ray photon

Which of the following statements is FALSE regarding occurrences after an X-ray photon penetrates the detector aperture? 1.) The photon can pass through the detector unmeasured 2.) The photon is converted completely into an electron 3.) The measured signal is enhanced by an amplifier 4.) All the above

2.) The photon is converted completely into an electron

Which of the following is false regarding CT systems? 1.) They are limited to non oblique transverse scanning 2.) They cannot generate a straight coronal or sagittal image 3.) They have no moving parts 4.) all the above

4, All the above. All are false statements

The Cathode filament: A.) helps determine the size of the focal spot B.) Lights up the tube so I can be serviced by an engineer C.) Releases the x-ray photons D.) Focuses x-rays onto the anode target

A.) Help determine the size of the focal spot

Which of the following statements is FALSE regarding the collection of CT data? A.) Long Scan times are more desirable because they average out motion artifacts B.) The reconstruction process used to create the image occurs int eh array processor C.) To collect the complete set of CT data, x-rays must be passed through the body at many different angles D.) The detectors measure x-rays which completely penetrate the patient

A.) Long scan times are more desirable because they average out motion artifacts - FALSE

The Patient table: A.) May move continuously during the scan B.) Can never be positioned automatically by software due to safety precautions C.) Remains stationary throughout then patient exam once it is initially positioned D.) Only moves after each slice is completed

A.) May move continuously during the scan

The mA determines the: A.) Quantity of x-ray photons B.) Coefficient of attenuation C.) Slice Thickness D.) Energy level of the x-ray photons

A.) Quantity of x-rays photons. mA = Quantity

Which of the follow is NOT a function of a PACS system? A.) Reconstruction of the image from the raw data B.) Long term data storage C.) Digital Distribution of images D.) Image display for the radiologists

A.) Reconstruction of the image from the raw data is NOT a function of PACS

Tube interscan delay time refers to: a. the time between the end of one scan and the start of the next scan during which the tube will cool b. a quality assurance test performed daily by the technologist c. the time required for the tube to make a complete 360 revolution about the gantry d. the length of time required for the production of photons to begin after applying the voltage to the tube

A.) Tube interscan delay is The time between the end of one scan and the start of the next scan during which the tube will cool

In order for an x-ray photon to be measured it must: 1.)Enter the detector 2.)Be absorbed by the detector material 3.) Be Converted to a measurable event 4.) All the above

All the above, A photon to be measured must enter the detector, be absorbed by the detector material and be converted to a measurable event

CT images can be directly scanned in planes other than transverse by: 1. orienting the patient's body part so that it is not perpendicular to the x-ray beam 2. tilting the gantry 3. changing the angle that the x-ray beam leaves the tube a. 1 only b. 1 & 2 c. 2 & 3 d. 1, 2 & 3

B. 1 & 2 1. orienting the patient's body part so that it is not perpendicular to the x-ray beam 2. tilting the gantry

Which of the following is NOT a part of the CT Tube? A.) Tungsten Target B.) Collimator C.) Rotating Anode D.) Filament

B. Collimator. Collimators are present pre patient and post patient. The filament is in the tubes cathode, and tungsten target, in the anode.

CT is commonly referred to as al of the following names EXCEPT: a. computerized axial tomography b. digital subtraction angiography c. CAT scan d. computed tomography

B. Digital subtraction angiography

Which of the following are NOT commonly used on todays commercially available CT scanners? 1.) Xenon detectors 2.) Fourth Generation technology 3.) Continuous rotation technology A.) 1 B.) 1 & 2 C.) 2.& 3 D.) 1, 2, 3

B.) 1&2, Not common are xenon detectors and fourth generation technology

Which technology do multi row detector scanners employ? A.) 2nd Generation B.) 3rd Generation C.) 4th Generation D.) 1st Generation

B.) 3rd Generation use Multirow detectors

Most of the commands from the technologist are received by the : a. array processor b. operator's console c. host computer d. amplifier

B.) Operators console, most of the commands from the technologist are receive by the operators console

What control does the operator have over the x-ray in the CT exam? a. the temperature and color of the x-ray can be tuned b. the energy level and the quantity of x-rays can be selected c. the volume and tone of the x-ray can be adjusted d. the phase and frequency of the x-ray can be adjusted

B.) the energy level and the quantity of x-rays can be selected (kV and mA)

The CT x-ray tube rotates around the patient to: 1. Keep the tube cool 2.) Generate projection views at different angles 3.) Minimize the x-ray dose administered to the patient A.) 1 B.) 2 C.) 3. D.) 1, 2 & 3

B.2 Generate projection view at different angles

Which system component converts the projection attenuation data into the proper digital form from the array processor? A.) Detector B.) Photodiode C.) Analog to digital converter D.) Host Computer

C. ) Analog to digital converter. The detector generates an electrical impulse in response to x-rays. The intensity of this electrical impulse is proportional to the number of x-rays that are absorbed by the detector any point in time. The electrical pulse is amplified, sampled and digitized.

Which of the following does NOT affect the quantity of x-rays that completely penetrates the patient? 1.) The distance that the x-ray photons must travel on their course through the patients body 2.) The molecular composition of the tissues through which the x-ray photons pass 3.) The type of detector material use A.) 1 B.) 2 C.) 3 D.) 1, 2, & 3

C. The type o detector material used

_________ allows remote authorized individuals to connect to a server in a secure fashion using the routing infrastructure provided on a public network, such as the internet A.) DICOM B.) T1 Lines C.) VPN D.) Increased bandwidth

C. VPN

Which of the following is a component NOT normally located in the gantry of a modern CT system? A.) Pre patient collimators B.) Solid-state drives C.) Array Processor D.) X-ray tube

C.) Array Processor. The array processor is located near the host computer and away from the gantry

The main purpose of the detector is to: A.) Provide additional collimation in order to reduce scatter B.) Limit the x-ray dose to the patient C.) Capture x-ray photons and convert them to a measurable event D.) Amplify the measured signal

C.) Capture x-ray photons and convert them into a measurable signal

Which of the following CT scanner designs does NOT use an x-ray tube? A.) 1st generation CT B.) PET/CT C.) Electron Beam CT D.) MDCT

C.) Electron Beam CT

Scatter radiation is caused by? A.) miscalibrated detector B.) X-rays generated spontaneously in the ambient atmosphere C.) Deflections from the original trajectory of the x-ray photon through the patient D.) Improper patient positioning

C.) Scatter is caused by deflections from the original trajectory of the x-ray photon through the patient

Which of the following statements is true? 1.) kV is the voltage potential between the tube cathode and anode while mA ultimately controls the filament current and, thus, the filament 2.) kV controls the energy level of the x-ray photons and mA controls the number of x-ray photons emitted from the tube 3.) Although the kV and the mA affect the operation of the CT x-ray tube, the two parameters have no bearing on the image quality A.) 1 B.) 2 C.) 1&2 D.) 2&3

C.) The kV is the voltage potential between the tube cathode and anode while mA ultimately controls the filament current and, thus, the filament 2.) kV controls the energy level of the x-ray photons and mA controls the number of x-ray photons emitted from the tube

X-Rays are used in CT because: A.) They are easily produced by the high frequency generator B.) they are less harmful than heating effects of microwave radiation C.) They penetrate the body according to specific attenuation characteristics of each tissue D.) The FDA imposes no limit on the dose of the patient

C.) They penetrate the body according to specific attenuation characteristics each tissue. X-rays are used in CT because

The number of electrons that flow from the cathode to the anode is controlled by the: A.) Anode target B.) Collimation C.) mA D.) kV

C.) mA

Which of the following is TRUE regarding multi-row detectors for CT scanners? 1.) The size of the detector arrays along the z-direction may be different 2.) The attenuation information from adjacent detector arrays may be added together to generate thicker slices 3.) All of the detector arrays may or may not be used A.) 1 B.) 2 C.) 3 D.) 1, 2 & 3

D 1,2,3 1.) The size of the detector arrays along the z-direction may be different 2.) The attenuation information from adjacent detector arrays may be added together to generate thicker slices 3.) All of the detector arrays may or may not be used

Which of the following is the standard thats used to achieve compatibility for image transfer between various imaging modalities, viewing stations, and printers in a hospital? A.) TCP/IP B.) T1 C.) PACS D.) DICOM

D DICOM.

Tungsten is used as the target material on the tubes anode because it has a ___ atomic number and a ____ melting point A.) Low, high B.) High, low C.) Low, low D.) High, High

D, High, High

The slip ring of continuous rotation CT scanners: 1.) Prevents the high voltage cable from winding up 2.) Allows the exam to commence more rapidly 3.) Eliminates the need for the reversal of gantry frame rotation A.) 1 B.) 2 C.) 3 D.) 1, 2, 3

D. All of the above 1.) Prevents the high voltage cable from winding up 2.) Allows the exam to commence more rapidly 3.) Eliminates the need for the reversal of gantry frame rotation

radiology department, a _________ is an example of a "client" on the network 1.) CT Scanner 2.) Viewing console in the physicians reading room 3.) Printer for diagnostic imaging A. 1 B. 2 C.) 2&3 D.) 1, 2 & 3

D. All the above. CT scanner, viewing console and printer are "Clients"

_____________ made helical image possible. A.) Multi Row detectors B.) The introduction of second generation technology C.) The introduction of 4th generation technology D.) Continuous rotation scanners

D. Continuous rotation scanners made helical image possible

Collimation in CT: A.) Is accomplished by electrically blocking x-rays B.) Affects the scan time C.) limits the low energy photons D.) Is accomplished by physically blocking x-rays

D. Is accomplished by physically blocking x-rays

On a single row detector scanner, collimation: 1.) Controls the slice thickness 2.) Minimizes the x-ray dose to the patient 3.) Reduces the detection of scatter radiation A.) 1 B.) 2 C.) 3 D.) 1, 2 & 3

D.) 1.) Controls the slice thickness 2.) Minimizes the x-ray dose to the patient 3.) Reduces the detection of scatter radiation

The operator's console may include: 1. monitor 2. keyboard 3.graphic input device a. 1 only b. 2 only c. 3 only d. 1, 2 & 3

D.) 1,2 and 3

Which of the following is TRUE regarding solid states detectors? 1.) x-ray photons cause the detectors to generate a flash of light 2.) They are the detector type used on most CT scanners today 3.) They can be used in both third generation and fourth generation CT Systems A.) 1 B.) 2 C.) 3 D.) 1, 2 & 3

D.) All the above 1.) x-ray photons cause the detectors to generate a flash of light 2.) They are the detector type used on most CT scanners today 3.) They can be used in both third generation and fourth generation CT Systems

The enormous heat that builds up in the CT tube is caused by the: A.) Intensity of the x-rays emitted from the tube B.) Electron beam between the cathode and the anode in the tube C.) X-ray filter in the tube which absorbs the lower energy photons before they can enter the patient D.) Collision of the electron beam with the tungsten target on the tube anode

D.) Collision of the electron beam with the tungsten target on the tube anode

Increase in ___ will increase the likelihood that a given x-ray will penetrate a material 1.) kV 2.) mA 3.) Exposure Time

kV