RAD 202 Exam 3
A ____ artifact is caused by attenuation of the beam as it passes through the patient. a. beam-hardening b. ring c. star d. streak
A
A series of tissue density values that evolved for CT measurements is called ____ units. a. Hounsfield b. H & D c. attentuation d. iterative
A
Each of the following is an example of an RF pulse sequence EXCEPT a. stationary b. spin -echo c. gradient d. inversion recovery
A
First-generation CT scanners scanned the _________ only. a. head b. thorax c. abdomen d. pelvis
A
If a piece of equipment, object, or device is to be used for a MR procedure, it is important to a. check its labeling by the ASTM Standard F2503. b. check it first with a small personal magnet before using it in the scan room. c. contact the MR vendor to check compatibility with the scanner. d. bring it into the scan room prior to the patient's entry, to check its safety.
A
Protons will alternate from a parallel to antiparallel. b. parallel to neutral. c. perpendicular to positive. d. positive to negative.
A
The CT radiographer usually varies the ____ to control the primary beam. a. mA b. time c. kVp d. distance
A
The CTDI dose measurement a. is slice-based. b. takes into account the total amount of irradiated tissue. c. represents the average total dose to the patient during the examination. d. measures entrance skin exposure (ESE).
A
The MHz frequency magnetic field for MRI is produced by a/an a. radio transmitter coil b. optical cable c. digital converter d. none of the above
A
The RF signal strength determines a. brightness b. field strength c. section thickness d. spatial resolution
A
The ____ is how well the detectors receive photons from the patient. a. capture efficiency b. absorption efficiency c. conversion efficiency d. response time
A
The amount of heat load an anode can tolerate for a sequence of exposures is known as: a. short-term loading ability b. continuous heat-loading ability c. tube-rate loading ability d. dose-dependent loading
A
The desirable features of a modern angiographic patient table include: 1. fixed vertical height with integrated physician stool 2. carbon-fiber composite top 3. side rails for the attachment of accessory items 4. free-floating tabletop motion 5. variable vertical height of table top 6. leaded composite material to increase photoelectric interactions 7. interchangeable table plates a. 2, 3, 4, 5, and 7 b. 1, 2, 3, 6, and 7 c. 2, 4, 5, and 7 d. 2, 4, 5, 6, and 7
A
The pressure of a contrast medium injector is measured in a. pounds per square inch b. pounds per cubic centimeter c. force per density d. viscosity per square inch
A
The process of modifying pixel values by a mathematical formula is called a. convolution b. deconvolution c. calculus d. interpolation
A
The quantity of resonating spins in a tissue expressed as a percentage of the proton density of water is a. spin density. b. repetition time (TR). c. echo time (TE). d. inversion time (TI).
A
The rotation of the axis of rotation is termed a. precession b. rerotation c. nuclear orientation d. frequency
A
The source of magnetic fields within the body a. is the spinning nucleus of an atom. b. are the neutrons. c. are the stationary electrons. d. all of the above
A
What is required for an analog image intensifier to produce a digital image? a. CCD b. PAC's c. DICOM d. LAN
A
When gradient coils are referred to, the z axis coil is referred to as the ____ gradient. a. selection b. phase encoding c. frequency encoding d. none of the above
A
A ____ artifact is caused by detector error. a. beam-hardening b. ring c. star d. streak
B
Before performing an MR scan on a patient with compromised renal function, a. the patient should be NPO for 24 hours. b. the patient's GFR should be assessed. c. an IVU should be performed. d. an ultrasound study of the kidneys should be done.
B
CT image data is acquired in the a. coronal plane and reconstructed in the axial plane . b. transverse plane and reconstructed in any plane. c. sagittal plane . d. axial plane and reconstructed in the coronal plane.
B
Contemporary CT scanners use solid state detectors. These detectors utilize a. sodium iodide crystals b. rare earth ceramic scintillators c. xenon gas d. freon gas
B
In a MR gantry, the patient lies at a. the lowest gantry level b. isocenter c. geometric center d. the center of the external coils
B
In order for a CT x-ray photon to be measured, it must 1. enter the detector 2. be absorbed by the detector material 3. transmit through the detector to be back-projected 4. have sufficient energy to undergo a Compton interaction 5. be converted to light and then electrical energy as a signal a. 1, 3, 4, and 5 b. 1, 2, and 5 c. 1, 2, and 4 d. 1, 4, and 5
B
In order to perform digital subtraction angiography, a. a mask image is acquired after injection. b. bony anatomy is eliminated from the final image. c. patient motion is not a concern, as this is a post-processing function. d. the injection image is acquired before the scout image is taken and then subtracted from the other.
B
In the event a CT patient needs emotional support for a procedure, during the acquisition a. patient restraints should be used. b. a patient family member should be allowed to attend to the patient. c. the department nurse should be asked to attend to the patient. d. the CT supervisor should stand by the patient.
B
Superconductive magnets used in MR are characterized by a. field strengths of .2T-.35T. b. the use of liquid helium as a cryogen. c. resistive magnets with vertical fields. d. the ability to turn the magnetic field on and off at will.
B
The Larmor frequency is the ____ frequency. a. quantum b. precessional c. linear d. all of the above
B
The ____ is how well the detectors convert incoming photons. a. capture efficiency b. absorption efficiency c. conversion efficiency d. response time
B
The actual response of proton spin to an RF pulse is to a. change the magnetic moment in a recovery circular motion. b. change the magnetic moment in a precessing corkscrew motion. c. remain stationary. d. change the magnetic moment in a precessing circular motion.
B
The amount of heat an anode can tolerate during a fluoroscopic exposure is known as ____ loading ability. a. short-term b. continuous-heat c. pulsed fluoro d. intermittent fluoro
B
The basic principle of MR physics involves an established relationship between an external magnetic field and the gyromagnetic ratio of an atom. This is expressed as the a. inverse square law. b. Larmor equation. c. Hounsfield coefficient. d. H & D curve.
B
The combination of field of view (FoV), acquisition matrix, and slice thickness determines the MR data element known as a a. pixel b. voxel c. byte d. magnetic moment
B
The contrast medium warming device on the pressure injector is intended to a. bring the contrast medium to room temperature. b. maintain the temperature of the contrast medium. c. bring the contrast medium to body temperature. d. increase contrast viscosity through warming.
B
The most recent generation of CT scanners use a ____ motion. a. translate-rotate b. helical c. linear d. elliptical
B
The time interval between pulse sequences is a. spin density. b. repetition time (TR). c. echo time (TE). d. inversion time (TI).
B
Vascular imaging using angiography requires a. single-phase input and three-phase output. b. generators with 1 ms interrogation and forced extinction times. c. C-arm rotational capability during image acquisition. d. 500 kHU x-ray tubes at a minimum.
B
What type of image acquisition is used when eliminating bone and soft tissue structures from an image so that only contrast-filled vessels remain? a. digital angiography b. digital subtraction angiography c. digital cineradiography d. image reversal angiography
B
When gradient coils are referred to, the y axis coil is referred to as the ____ gradient. a. selection b. phase encoding c. frequency encoding d. none of the above
B
A ________ artifact is caused by the presence of metal in the patient. a. beam-hardening b. ring c. star d. streak
C
CT scan pitch uses all of the following technical parameters EXCEPT a. slice thickness b. 360-degree gantry rotation c. acquisition mAs d. table increment
C
Contrast-enhanced MR images use ________as the contrast material of choice. a. iodine b. barium c. gadolinium d. hydrogen
C
Digital image receptors used in angiography a. require a CCD for image capture. b. are composed of selenium detector material. c. acquire the images digitally in the detector material. d. permit post-processing of images, unlike analog image intensifier detectors.
C
Most angiographic studies are produced at what kVp range? a. 30 to 40 b. 40 to 50 c. 50 to 100 d. 75 to 110
C
The ____ is determined by how well the detector converts the absorbed photon information to a digital signal for the computer. a. capture efficiency b. absorption efficiency c. conversion efficiency d. response time
C
The calculation of CT numbers is based upon the calculation of a. half-value layer b. half-lives c. attentuation coefficients d. pitch
C
The characteristic MR noise that is uncomfortable for patients and staff is due the ________ turning on and off at a high frequency. a. external magnet b. external coils c. gradient coils d. RF coil
C
The gantry of the CT unit contains the a. post-processing workstation b. operator's interface c. x-ray tube d. all of the above
C
The gyromagnetic ratio is the ratio of the magnetic a. moment to the moment of magnetic force. b. force to the moment of inertia. c. moment to the moment of inertia. d. none of the above
C
The localization image produced by the CT scanner is technically called a/an a. volume rendered image b. scout film c. scanogram d. FOV image
C
The most widely used technique for MR image reconstruction is a. back projection. b. interpolation. c. fast Fourier transformation (FFT). d. Larmor equation precession (LEP).
C
The primary variable in the data collection procedure during MRI is the a. repeats b. stationary magnet c. sequence of RF pulses d. all of the above
C
The process of combining detector elements into various combinations in order set slice thickness is called detector a. modulation b. dose efficiency c. binning d. interpolation
C
The range of CT numbers or Hounsfield Units varies from a. 100 to 300 b. -100 to +300 c. -1,000 to +3,000 d. 1,000 to +3,000
C
The size of the tissue voxel determines a. brightness b. field strength c. section thickness d. spatial resolution
C
The time between a 90-degree pulse and the echo during a spin-echo pulse sequence is a. spin density. b. repetition time (TR). c. echo time (TE). d. inversion time (TI).
C
To achieve coronal and sagittal sections, a. the gantry is repositioned b. the patient is repositioned c. reconfiguration software is implemented d. none of the above
C
To produce magnetic field gradients in MRI, electromagnetic coils are oriented in a. one dimension b. two dimensions c. three dimensions d. four dimensions
C
What type of image acquisition is used mainly for cardiac catheterization? a. digital angiography b. digital subtraction angiography c. digital cineradiography d. cineangiographic imaging
C
When gradient coils are referred to, the x axis coil is referred to as the ____ gradient. a. selection b. phase encoding c. frequency encoding d. none of the above
C
Which can serve as both the transmitter and receiver of the MRI signal? a. the stationary magnet b. the gradient coils c. the RF coils d. the cryogen coils
C
Which of the following will permit a greater volume of contrast injection per unit of time? a. lower psi injection rates b. longer catheter lengths c. catheter side-holes d. higher viscosity of contrast media
C
With MSCT scanners, resolution is primarily determined by a. prepatient collimation. b. dose. c. collimation at the detector. d. gantry rotation speed.
C
A ______ artifact is caused by motion. a. beam-hardening b. ring c. star d. streak
D
As noise increases in a CT image, a. low contrast resolution increases b. dose to the patient increases c. low contrast resolution decreases d. both a and c
D
Computed tomography sections are available as a. coronal b. transverse c. sagittal d. all of the above
D
Higher field strength MRI magnets permit: a. shorter scan times b. better resolution c. stronger signal strength d. all of the above
D
In MRI, the primary visual factor is often called: a. linearity b. geometric shape c. resolution d. brightness
D
In order to create a more homogenous magnetic field in MR, _______ is required a. a radio frequency b. a k-space coil c. an autotransformer d. shimming
D
MRI has been achieved with _____ magnets: a. resistive b. permanent c. superconductive d. all of the above
D
MSCT scanners have evolved greatly over the last few years, particularly with regard to slice combinations, scanning speed, and clinical utility. As these scanners gather more slices of data per rotation, a major technological challenge is a. the amount of data handled by the computer. b. the number of images to be analyzed by the clinician. c. developing technologies to minimize dose. d. all of the above
D
Modern pulsed CT scanners operate at a. 120 kVp b. 1 to 5 msec. pulses c. up to 1,000 mA d. all of the above
D
Of the choices below, the preferred method for angiographic image acquisition is a. roll film changer because of speed. b. cut film changer because of film-screen contact. c. cineangiographic camera because of high frame rates and low dose. d. digital imaging technology because of post-processing functionality.
D
Patient precautions with MR scanning include a. claustrophobia. b. not touching the inside of the gantry during scanning. c. ferromagnetic implants or prosthetic devices. d. all of the above
D
Quality control programs in the vascular imaging laboratory require a. a close relationship with the equipment vendor. b. periodic monitoring of viewing systems such as video monitors. c. in-house biomedical engineers working at a "first-line " level supported by the vendor. d. all of the above
D
Select the TRUE statement from the choices below. a. Extinction time is the time required to prepare the x-ray tube for exposure. b. Window level adjusts the contrast and window width adjusts the density of an image. c. The flow rate is the rate at which the contrast medium is filtered by the kidneys. d. The typical design of the vascular imaging system uses a C-arm configuration.
D
The CT console provides the radiographer access to a. the software program b. data acquisition c. data display d. all of the above
D
The CT radiation beam is collimated a. at the tube exit b. at the detector entrance c. pre-patient and post-patient d. all of the above
D
The CT table is a. made of carbon graphite b. rated for maximum weight c. motor-driven d. all of the above
D
The gradient coils determine the a. section thickness b. resolution c. plane of the image d. all of the above
D
The heat-loading capacity of an x-ray tube depends on a. focal spot size b. anode angle c. generator configuration d. all of the above
D
The most common variable in operating an MRI unit is the ____ used to enhance image quality. a. TI b. TE c. TR d. all of the above
D
The primary mathematical method used in the creation of computerized medical images is the ____ transformation. a. interpolation b. Hounsfield c. algorithm d. Fourier
D
The resolution of the CT image depends on the a. pixel b. voxel c. matrix size d. all of the above
D
The smaller the scan field size, the a. better the resolution b. faster the scan time c. less of risk of motion d. all of the above
D
The strength of a MR signal is a. directly proportional to the strength of the magnetic filed. b. directly proportional to the strength of BO. c. directly related to the tesla of the magnet. d. all of the above
D
The time between a 180-degree pulse and a 90-degree inversion pulse in an inversion recovery pulse system is a. spin density. b. repetition time (TR). c. echo time (TE). d. inversion time (TI).
D
The time required after precessing spins have aligned at an angle to the external field due to an RF pulse losing 63% of their coherence is a. spin density. b. repetition time (TR). c. echo time (TE). d. spin-lattice relation time
D
The time required for precessing spins to align with the constant external field to 63% of the maximum possible strength is a. spin density. b. repetition time (TR). c. echo time (TE). d. spin-lattice relation time
D
To prevent extraneous RF signals from degrading MR image quality, MR scan suites are enclosed in a a. copper cage b. steel cage c. Faraday cage d. both a and c
D
Vascular imaging generators should have the capacity to deliver ____ mA. a. 50 b. 190 c. 300 d. 1,000
D
Which type of generator is typically chosen for use during cardiovascular and interventional angiographic procedures? a. single-phase b. three-phase, 6 pulse c. three- phase, 12 pulse d. high frequency
D
X-ray tubes used in vascular interventional procedures a. require mega heat unit tubes. b. have graphite-backed anodes for heat tolerance. c. have a larger anode disk diameter and thickness. d. all of the above
D
