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Computed Tomography Registry
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Title
Computed Tomography Registry
Description
questions to prepare for ARRT Computed Tomography Exam
Total Cards
202
Subject
Medical
Level
Graduate
Created
01/14/2009
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Cards Term
Definition
Tungsten is used as the target material on the tube's anode because it has a ____ atomic number and a ____ melting point. a. low,high b. high, low c. low, low d. high, high
Term
Answer: d. high, high
Definition
________ scanner design was teh first to acquire four slices in a single rotation. a. Second-generation b. Third-generation c. Multi-row detector d. Continuous rotation
Term
Answer: c. Multi-row detector
Definition
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 Term
d. collision of the electron beam with the tungsten target on the tube anode
Definition
The number of electrons that flow from the cathode to the anode in the tube is controlled by the: a. anode target b. collimation c. mA d. kV
Term
Answer: c. mA
Definition
The slip ring on continous 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 only b. 2 only c. 3 only d. 1,2,&3 Term
Answer: d. 1,2,&3
Definition
Which of the followind is NOT a part of the CT tube? a. tungsten target b. collimator c. rotating anode d. filament
Term
Answer: b. collimator
Definition
Which of the following are NOT commonly used on today's commecially available CT scanners? 1. xenon detectors 2. fourth-generation technology 3. continuous rotation technology a. 1 only b. 1 & 2 c. 2 & 3 d. 1, 2, &3 Term
Answer: b 1&2
Definition
Which system component converts the projection attenuation data into the proper digital form for the array processor? a. detector b. photodiode c. analog-to-digital converter d. host computer
Term
Answer: c. analog-to-digital converter
Definition
X-ray photons are produced by a fast-moving electron: 1. colliding with an atomic nucleus 2. passing close to an atomic nucleus 3. colliding with an electron within an atom and ejecting it a. 1 only b. 2 only c. 3 only d. 1,2,&3 Term
Answer: d. 1,2,&3
Definition
Which of the following is TRUE regardin solid state 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 fourthgeneration CT systems a. 1 only b. 2 only c. 3 only d. 1,2, &3 Term
Answer: d. 1,2, &3
Definition
CT is commonly referred to as all of the following names EXCEPT: a. computerized axial tomography b. digital subtraction angiography c. CAT-scan d. computed tomography
Answer: b. digital subtraction angiography
Term
Definition
What control does the operator have over the x-rays in a CT exam? a. the temperature and color of the x-rays can be tuned b. the energy level and the quantity of x-rays can be selected c. the volume and tone of the x-rays can be dialed d. the phase and frequency of the x-rays can be adjusted
Term
Answer: b. the energy loevel and the quantity of x-rays can be selected
Definition
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 temperature of the cathode filament 2. kV contols 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 only b. 2 only c. 1 & 2 d. 2 & 3 Term
Answer: c. 1 & 2
Definition
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 patient's body 2. the molecular composition of the tissues through which the x-ray photons pass 3. the type of detector material used a. 1 only b. 2 only c. 3 only d. 1,2, &3 Term
Answer: c. 3 only
Definition
____________made helical imaging possible. a. Multi-row detector scanners b. The introduction of second-generation technology c. The introduction of fourth-generation technology d. Continuous rotation scanners
Term
Answer: c. continuous rotation scanners
Definition
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 in the array processor c. to collect the complete set of CT data, xrays must be passed through the body at many different angles d. the detectors measure x-rays which completely penetrate the patient Term
Answer: a. long scan times are more desirable because they average out motion artifacts
Definition
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 detectors c. array processor d. x-ray tube
Term
Answer: c. array processor
Definition
X-rays are used in CT because: a. they are easily produced by the high frequency generator b. they are less harmful than the 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 to the patient
Term
Answer: c. they penetrate the body according to specific attenuation characteristics of each tissue
Definition
Bremsstrahlung radiation does NOT include which type of electron activity? 1. collision between an incoming electron and the nucleus of the target atom 2. collision between an incoming electron and an electron in an inner shell of the target atom 3. slowing down of an incoming electron due to the effect of passing close to the positive charge of the nucleus of the target atom a. 1 only b. 2 only c 3 only d. 1,2, &3 Term
Answer: b. 2 only
Definition
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
Answer: a. quantity of x-ray photons
Term
Definition
Increased_____will increase the likelihood that a given x-ray will penetrate a material. 1. kV 2. mA 3. exposure time a. 1 ony b. 2 only c. 3 only d. 1,2,&3 Term
Answer: a. 1 only
Definition
Collimation: a. is accomplished by electrically blocking x-rays b. affects the scan time c. limits the low energy x-ray photons and passes the high energy photons d. is accomplished by physically blocking x-rays
Term
Answer: d. is accomplished by physically blocking x-rays
Definition
Scatter radiation is caused by: a. miscalibrated detector b. x-rays generated spontaneously in the ambient atmosphere c. deflections from the original trajectory of an x-ray photon through the patient d. improper patient positionins
Term
Answer: c. deflections from the original trajectory of an x-ray photon through the patient
Definition
Which technology do multi-row detector scanners employ? a. second-generation b. third-generation c. fourth-generation d. first-generation
Answer: b. third-generation
Term
Definition
Which of the following 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
Term
Answer: a. reconstruction of the image from the raw data
Definition
Which of the following is TRUE regarding multi-row detector 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 only b. 2 only c. 3 only d. 1,2, &3 Term
Answer: d. 1,2, &3
Definition
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 a. 1 only b. 2 only c. 3 only d. 1,2, &3 Term
Answer: d. 1,2, &3
Definition
Most of the commands from the technologist are received by the: a. array processor b. operator's console c. host computer d. amplifier
Answer: b. operator's console
Term
Definition
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
Answer: d. 1,2, &3
Term
Definition
Which of the following CT scanner designs does NOT use an x-ray tube? a. firt-generation CT b. PET/CT c. electron beam CT d. MDCT
Term
Answer: c. electon beam CT
Definition
Tube interscan delay time refers to: a. the time betweeen the end of one scan and the start of the next scan during which the tube will coll b. a quality assurance test performed daily by the technologist c. the time required for the tube to make a complete 360 degree revolution about the gantry d. the length of time required for the production of photons to begin after applying the voltage to the tube Term
Answer: a. the time between the end of one scan and the start of the next scan during which the tube will cool
Definition
On a single-row detector scanner, collimation: 1. controls teh slice thickness 2. minimizes the x-ray dose to the patient 3. reduces the detection of scatter radiation a. 1 only b. 2 only c. 3 only d. 1,2, &3
Answer: d. 1,2, &3
Term
Definition
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 signal d. amplify the measured signal
Term
Answer: c. capture x-ray photons and convert them to a measurable signal
Definition
In order for an x-ray photon to be measured it must: 1. enter the detector chamber 2. be absorbed by the detector material 3. be converted to a measurable event a. 1 only b. 2 only c. 3 only d. 1,2, &3
Term
Answer: d. 1,2, &3
Definition
The patient table: a. may move continuosly during the scan b. can never be positioned automatically by software due to safety precautions c. remains stationary throughout the patient exam once it in initially positioned d. only moves after each slice is completed
Term
Answer: a. may move continuously during the scan
Definition
Which of the following statements is FALSE regarding occurrences afte an x-ray photon penetrates the detector aperature? 1. the photon can pass through the detector unmeausred 2. the photon is converted completely into a n electron 3. the measured signal is enhanced by an amplifier a. 1 only b. 2 only c. 3 only d. 1,2, and 3 Term
Answer: b. 2 only
Definition
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 and 2 c. 2 and 3 d. 1,2 and 3 Term
Answer: b. 1 and 2
Definition
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 1. 1 only 2. 2 only 3. 3 only 4. 1,2, &3
Term
Answer: b. 2 only
Definition
The cathode filament: a. helps determine the size of the focal spot b. lights up the tube so it can be serviced by an engineer c. releases the x-ray photons d. focuses electrons onto the anode target
Term
Answer: d. focuses electrons onto the anode target
Definition
The goals of history-taking include all of the following EXCEPT: a. assessing the patient's risk factors for IV contrast reactions b. verifying the accuracy of the information in the patient's chard c. verifying that the patient has signed a living will and durable power of attorney d. establishing an initial rapport with the patient Term
Answer: c. verifying that the patient has signed a living will and durable power of attorney
Definition
Patients who have had a prior allergic reaction to a contrast agent should be asked all of the following EXCEPT: a. how severe were the symptoms? b. what was the nature of the reaction? c. what medications were you taking at the time? d. how were the symptoms treated?
Term
Answer: c. what medications were you taking at the time?
Definition
The localizer scan for a chest CT scan should encompass the ______ superiorly to the _________inferiorly. a. thoracic inlet, adrenal glands b. thoracic inlet, diaphragm c. cricoid cartilage, adrenal glands d. thymus, superior surface of the liver
Term
Answer: a. thoracic inlet, adrenal glands
Definition
Regardless of the clinical indication, all chest CT scans must display the ______on the initial image. a. lung roots b. aortic arch c. pulmonary arteries d. lung apices
Term
Answer: d. lung apices
Definition
Which of the following statements regarding the use of IV contrast in the assessment of lung, mediastinal masses and lung cancer diagnosis is TRUE? a. IV contrast is generally ineffective for the identification of hilar masses b. IV contrast can differentiate lung cancers from pneumonia, as the latter enhance brightly on scanning c. contrast is effective for delineating mediastinal masses from surrounding mediastinal vessels d. neither lung infiltrates nor intraparencyhymal lung cancers will enhance with the use of iodinated contrast Term
Answer: c. contrast is effective for delineating mediastinal masses from surrounding mediastinal vessels
Definition
The_____is a thin membrane that lines the abdominal cavity from the diaphragm to the pelvis a. mesentery b. peritoneum c. omentum d. pleura
Term
Answer: b. peritoneum
Definition
Compared with a polyethylene glycol regimen, a CT colonoscopy bowel preparation consisting of oral hydration with a cathartic for colon contraction produces: a. a drier colon b. fluid pools in the transverse colon c. more abdominal crampin d. large pockets of trapped gas
Term
Answer: a. a drier colon
Definition
Which one of the following is NOT an anatomic structure contained in the mediastinum? a. pleurae b. aorta c. trachea d thymus
Answer: pleurae
Term
Definition
Diffuse or interstitial lung disease is assessed at the level of the : a. alveoli b. secondary lobules c. bronchioles d. acini
Term
Answer: b. secondary lobules
Definition
For routine abdominal and pelvic scans, the preferred rate of dlivery of intravenous contrast is ____cc/sec: a. 1-2 b. 2-3 c. 3-4 d. 4-5
Term
Answer: b. 2-3
Definition
Which one of the following statements regarding CT scanning of the spleen is TRUE? a. the spleen shows uniform enhancement during the arterial phase b. the spleen shows a stripe-like enhancement during the portal venous phase c. routine abdominal protocols are generally used for spleen imaging d. the spleen appears more dense than the liver on unenhanced scans Term
Answer: c. routine abdominal protocols are generally used for spleen imaging
Definition
A Hounsfield value of +10 likely represents a/an: a. fibroid uterus b. diverticular abscess c. endometiral tumor d. ovarian cyst
Answer: d. ovarian cyst
Term
Definition
The_____is/are NOT located in the peritoneal cavity. a. spleen b. ileum c. kidneys d. gallbladder
Term
Answer: kidneys
Definition
The superior mesenteric artery supplies blood to all of the following areas EXCEPT the: a. pancreatic head b. sigmoid colon c. jejunum d. ileum
Term
Answer: b. sigmoid colon
Definition
The structures of the colon that give it a "pillow-like" appearance are called the: a. haustra b. segmental ligaments c. transverse ligaments d. tenia coli
Term
Answer: a. haustra
Definition
The opening through which the descending aorta passes through the diaphragm is called the aortic_____. a. arch b. hilum c. hiatus d. sinus
Term
Answer: c. hiatus
Definition
What types of reconstruction algorithms are used for routine chest CT scans with multislice scanners a. detail/high resolution b. standard/smooth c. standard/lung d. smooth/high resolution
Term
Answer: d. smooth/high resolution
Definition
Scan protocols for evaluating the pancreas can be used for all of the following indications EXCEPT: a. jaundice b. acute cholecystitis c. gastric cancer d. hepatitis
Term
Answer: d. hepatitis
Definition
The liver has a dual blood supply through the _______and _____. a. hepatic artery, portal vein b. celiac trunk, aorta c. portal hepatis, main portal vein d. celiac trunk, hepatic artery
Answer: a. hepatic artery, portal vein
Term
Definition
Preparation for breath-holding during the CT exam may encompass all of the following EXCEPT: a. propping frail patients up with pillows b. instructing patients to take numerous rapid, shallow breaths 5 minutes before the scan c. assessing the patient's ability to sustain a breath-hold for 30 seconds d. instructing patients who cannot hold their breath to breathe slowly Term
Answer: b. instructing patients to take numerous rapid, shallow breaths 5 minutes before the scan
Definition
Answer: Using __________ reconstruction filter would decrease the appearance of noise in a CT image. 1. no 2. a sharp 3. a smooth a. 1 only b. 2 only c. 2&3 d 3 only
Term
d
Definition
A___________ scan uses only a single projection. 1. conventional, or serial 2. helical 3. localizer a. 1 only b. 2 only c. 3 only d. 1,2,
Term
Answer: c. 3 only
Definition
Which of the following statements is FALSE regarding 3D SSD? a. helical image data is well suited for 3D SSD because there is minimal misregistration or gaps b. the volume data, from which the 3D SSD is generated, is created by combining transverse, sagittal, and coronal reconstructions c. the tissue surface may be selected by using a threshold value equal to the tissue's CT number d. patient motion during the scan is detrimental to the quality of the 3D images. Term
Answer: b
Definition
Answer: d. 1, 2, &3
Which type(s) of storage media may hold CT image data? 1. internal hard disk 2. CD 3. re-writable optiacal disk a. 1 only b. 2 only c. 3 only d. 1,2, and 3
Term
Definition
__________may have to be edited from the data set to get a diagnostic MIP of a CTA exam. a. lodinated contrast media b. vessels of interest c. air d. bones
Term
Answer: d
Definition
Which of the following is NOT an advantage of a helical study compared to a conventional, serial CT study? a. minimal anatomical misregistration sometimes caused by inconsistent breath-holdin b. shorter total exam time c. can retrospectively reconstruct a slice at any arbitrary position d. offers the best image quality for a brain exam
Term
Answer:d
Definition
Which of the following utilizes convolution? 1. 3D SSD 2. Fourier transform 3. filtered back projection a. 1 only b. 2 only c. 3 only d. 1,2, &3
Term
Answer:b
Definition
In which technique are tissues other than the surface of a structure excluded by setting a threshold value and eliminating pixels above or below that threshold? a. volume rendering b. multi-planar reconstruction c. maximum intensity projection d. 3D shaded surface display
Term
Answer:d
Definition
From which of the following can the most diagnostic multiplanar reconstructions be generated? 1. stacked transverse images from a helical scan 2. stacked transverse images from a conventional, serial scan 3. stacked localizer images a. 1 only b. 2 only c. 3 only d. 1,2, &3
Term
Answer:a
Definition
The actual attenuation data measured by the detectors from all projections during a scan is contained in CT ______data. 1. image 2. convolved 3. raw a. 1 only b. 2 only c. 3 only d. 1, 2,
Term
Answer:c
Definition
Which of the following is TRUE regarding the slice thickness of an image reconstructed from a helical scan? 1. on a multi-row detector scanner, the thickness is equal to the beam collimation 2. on a single-row detector scanner, the thickness is equal to the beam collimation 3. on a single-row detector scaneer, the thickness can be varied retrospectively a. 1 only b. 2 only c. 2&3 d. 1,2, &3
Term
Answer:b
Definition
A retrospective reconstruction, in which the reconstruction field-of view is varied, uses: 1. a reconstructed image in the sagittal plane b. CT raw data c. more photons d. CT image data
Term
Answer: b. CT raw data
Definition
Which of the following is common to both a localizer scan and a conventional, serial CT scan? a. they both produce digital images b. the patient table moves at a constant velocity c. they both produce cross-sectional images d. the x-ray tube makes complete 360 degree rotations
Term
Answer:a
Definition
Which of the following statements is TRUE? 1. the amplified electrical signal obtained from the detectors must be digitized 2. digital CT images are numerical representations of cross-sectional anatomy 3. digital signals may be formed by sampling analog signals at discrete time intervals a. 1 only b. 2 only c. 3 only d. 1, 2, & 3
Term
Answer:d
Definition
________is the mathematical process used by single-row detector scanners to reconstruct CT images from raw data. a. weighted averaging b. filtered back projection c. the fourier transform d. integration of the area under the curve
Term
Answer:b
Definition
3D shaded surface displays are performed on CT: 1 image data 2. raw data 3. attenuation profiles a. 1 only b. 2 only c. 3 only d. 1,2,&3
Term
Answer:a
Definition
A pixel is a : a. bright artifact on a film b. single 3D volume element within a volume of anatomical data c. single 2D picture element within the image plane d. range of gray levels on a CT image
Term
Answer:c
Definition
The pencil thin section of the x-ray fan beam that strikes a single detector is called a : a. line b. projection c. view d. ray
Term
Answer:d
Definition
A kernal is a : a. component in the x-ray tube b. postprocessing filter applied to image data c. type of detector d. filter applied to the CT rawdata
Term
Answer: d. filter applied to the CT rawdata
Definition
An increase in ______does NOT occur in the resulting images when applying a sharp, or high-pass reconstruction filter during the image reconstruction of CT raw data. 1. contrast resolution 2. edge enhancement 3. the appearance of noise a. 1 only b. 2 only c. 3 only d. 1,2,
Term
Answer: a. 1 only
Definition
________is the mathematical process used by single-row detector scanners to reconstruct CT images from raw data. a. weighted averaging b. filtered back projection c. the fourier transform d. integration of the area under the curve
Term
Answer:b
Definition
CTA images come from a ________scan. 1. conventional, or serial 2. helical 3. localizer a. 1 only b. 2 only c. 3 only d. 1,2,
Term
Answer: b. 2 only
Definition
If an image matrix has 360 rows and 360 columns, how many pixels are there in the image? a. 21,600 b. 129,600 c. 259,200 d. 379,800
Term
Answer: b. 129,600
Definition
The ______determines the intensity of the laser beam in a laser camera. 1. intensifying grid 2. pixel values in the image data 3. magnifying power of the lens. a. 1 only b. 2 only c. 3 only d. 1,2,
Term
Answer: b. 2 only
Definition
Which of the following is a reconstruction technique applied to the raw data after the primary reconstruction has already been accomplished? a. maximum intensity projection b. volume rendering c. retrospective reconstruciton d. multi-planar reconstruction
Term
Answer: c. retrospective reconstruction
Definition
What does convolution do to the image quality when it is added to the back projection reconstruction process? a. normalizes the attenuation coefficients to ensure tissues are displayed with correct CT numbers b. increases the number of projections thereby recucing streaking artifacts c. improves contrast resolution by reducing scatter radiation d. enhances important characteristics of attenuation profiles thus reducing stereak and star artifacts. Term
Answer:d
Definition
Which of the following may occur during the interscan delay of a conventional, or serial, CT scan performed on a continuous rotation scanner? 1. the table is incremented
answer: 4
2. the tube continues to rotate in the same direction as during the scan 3. the tube assembly makes a 360 degree rotation 4. all of the above
Term
Definition
______allows helical data to be converted into planar raw data. a. retrospective reconstruction Answer: b
b. interpolation c. cone beam reconstruction d. 1,2, &3
Term
Definition
What is the most common type of film used for recording CT images? a. thermal Answer: c
b. double emulsion c. single emulsion d. paper
Term
Definition
A helical scan performed on a 64 slice MDCT scanner is reconstructed with: a. back projection Answer:d
b. simple reconstruction because it is a single projection scan c. no reconstruction filter d. cone beam reconstruction
Term
Definition
______yields an image that appears 3D but also shows anatomical details above and below the 3D surface. a. SSD Answer:b
b. VR c. MIP d. multiplanar reconstruction
Term
Definition
MDCT scanners capable of collecting 64 slices in a single rotation do NOT: a. perform conventional CT scans Answer:c
b. perform helical CT scans c. use filtered back projection as their method of image reconstruction d.perform localizer scans
Term
Definition
MIP images: a. are most frequently used for visualizing air-filled spaces Answer:d
b. can NOT be run in a cine loop c. are most accurate when a large volume of interest is selected d. do NOT demonstrate detail beneath the brightest pixel
Term
Definition
Multi-planar reconstructions are performed on which of the following? 1. image data Answer:a
2. raw data 3. attenuation profiles 4. all of the above
Term
Definition
The ______move(s) during a helical scan on a thirdgeneration scanner. a. x-ray tube Answer: d
b. patient table c. detector elements d. all of the above
Term
Definition
A CT system manufacturer has a scanner in which the focal spot of the x-ray beam can move to two, slightly separated, distinct locations. What benefit does thef dual focal spot provide compared to an identical scanner possessing a single focal spot?
Answer:a
a. the number of projections is doubled b. the number of rays in a single projection is doubled c. the patient does is halved d. all of the above
Term
Definition
On a third-generation single-row detector scanner, if there are 715 detectors and there are 900 projections in a full rotation, how many samples of attenuation data are collected for the raw data of a single slice if the scan calls for an overscan of a 400 degree rotation?
Answer: c
a. 286,000 b. 643,500 c. 715,000 d. 845,000
Term
Definition
A smooth, or low-pass, reconstruction filter is typically NOT selected for a(n) _______exam. a. pituitary Answer:d
b. kidneys c. liver d. internal auditory canals
Term
Definition
In a __, the highest pixel values from a stack of CTA images are projected along many "rays". a. SSD
Answer:
b. MIP
b
c. PR d. VR
Term
Definition
The x-ray beam used in CT scanning is _______the patient's tissues. a. reflected off of
Answer:
b. attenuated by
b
c. generated by d. all of the above
Term
Definition
Which of the following are possible results of partial voluming? a. decreased sharpness of edges
Answer:
b. misleading CT numbers
c
c. improvement in resolution d. all of the above e. a&b
Term
Definition
Which of the following has the highest patient dose assuming all other parameters are the same? a. mA=200, rotation time=2 seconds
Answer:
b. mA=200, rotation time=1 second
c
c. mA=150, rotation time=3 second d. mA=400, rotation time =1 second
Term
Definition
CT numbers________would appear black if a window width of 400 and a window level of -100 are used. a. above +200
Answer:
b. below -300
b
c. below -200 d. above +100
Term
Definition
If a calcification with a CT number of +300 appears pure white on an image, which of the following could be the window width and window level selected? Answer:
1. wl=0, ww=500
a
2. wl=+300, ww=500 3. wl=+100, ww=1000 a. 1 only b. 2 only c. 3 only d. 2&3
Term
Definition
Which of the following determinants of CT imge quality is responsible for how grainy or speckled a CT image appears? Answer:
a. resolution
c
b. linearity c.noise d. contrast
Term
Definition
Whichi of the following statements is FALSE? a. magnification requires raw data b. increasing magnification increases resolution
Answer:
c. magnification decreases the size of displayed anatomy.
d
d. all of the above
Term
Definition
If a thin slice is used, which of the following would help reduce the apparent image noise? a. reduced reconstruction field of view
Answer:
b. increased matrix
c
c. inreased mAs d.increased kVp
Term
Definition
A CT Number Calibration Tst should be performed: a. weekly b.annually
Answer:d
c. monthly d. daily
Term
Definition
Which of the following is a reason to increase the pitch? 1. a greater volume of anatomy cn be covered in a given time
Answer:
2. a given volume of anatomy can be covered faster
c
3. radiation dose to the patient can be increased a. 1 only b. 2 only c. 1&2 d. 2&3
Term
Definition
Which of the following is FALSE about the spatial resolution of an image? 1. resolution is dependent on matrix size
Answer:
2. resolution is dependent on reconstruction FOV
c
3. resolution is dependent on scanned FOV a. 1 only b. 2 only c. 3 only d. 1, 2, and 3
Term
Definition
An increase in_______ will result in hardening ofan xray beam. 1. tissue density Answer:d
2. tissue thickness 3. kVp a. 1 only b. 2 only c. 3 only d. 1, 2, &3
Term
Definition
If the slice thickness s changed fro 5 mm to 7mm and all other parameters are held constant, ____% more photons will be used in making the slice. Answer:
a. 30
b
b. 40 c. 60 d.80
Term
Definition
Which of the following will result in an increased voxel size? 1. decreased reconstruction FOV
Answer:
2. increased slice thickness
b
3. increased matrix a. 1 only b. 2 only 3. 2&3 4. 1,2, &3
Term
Definition
If a reconstruction FOV of 32cm and a 512X512 matrix are used, the pixel size is _____mm. a. 0.35 X 0.35
Answer:
b. 0.625 x 0.625
b
c. 1.6 x 1.6 d. 3.25 x 3.25
Term
Definition
Which of the following does NOT occure when reconstruction FOV is decreased? a. spatial resolution is increased Answer: b
b. pixel size is increased c. noise in the image increases d. all of the above
Term
Definition
Which of the following is the conversion equation from CT number to Hounsfield unit? a. CT number=0.5 HU Answer:c
b. CT number= (HU)² c. CT number=HU d. CT number=2 x HU
Term
Definition
There are ______total pixels in a 1024 x 1024 matrix. a. 2048 b. 524,288
Answer: c
c. more than 1 million d. more than 2 million
Term
Definition
Which of the following occurs when slice thickness is reduced? a. appearance of noise in the image increases
Answer:
b. the number of photons used in making the slice decreases
d
c. partial volume averaging decreases d. all of the above
Term
Definition
Increasing ________results in lowering the patient dose. 1. pitch 2. mAs
Answer:
3. table increment
c
a. 1 only b. 1&2 c. 1&3 d. 1,2,&3
Term
Definition
_______affects the CT number of water. a. no imaging parameter
Answer:
b. the slice thickness
a
c. the kVp d. the mAs
Term
Definition
The smalles object that can be resolved if a reconstruction FOV of 24 cm and a 512 x 512 matrix are used is ____mm. Answer:
a. 0.47
a
b. 1.00 c. 2.13 d. 3.57
Term
Definition
If the radiologist requires 2mm thick contiguous slices through the pituitary and 2.4 cm of coverage, ___slices are necessary? a. 8
Answer: c
b. 10 c. 12 d. 13
Term
Definition
Which of the following is NOT a result of reducing the reconstruction FOV? a. improved spatial resolution Answer: c
b. increased appearance of image noise c. anatomical structures appear smaller d. all of the above
Term
Definition
Which of the following parameters affects the contrast of a CT image? a. reconstruction interval
Answer:
b. mAs
c
c. kVp d. CT number
Term
Definition
Which of the following parameters is responsible for partial volume averaging? a. matrix size
Answer:
b. kVp
c
c. slice thickness d. patient dose
Term
Definition
On MDCT, the final reconstructed slice thickness is determined by the:
Answer:
a. number of rows of detectors and the size of the detectors whose attenuation data gets combined
a
b. pitch c. reconstruction interval d. collimation
Term
Definition
The distance that the table travels between slices is called: a. table increment
Answer:
b. collimation
a
c. rotation d. reconstruction interval
Term
Definition
A set of images is reconstructed with a 150 mm reconstruction FOV. Keeping all other parameters constant, a second set of images is reconstructed with a 300 mm reconstruction FOV, and then magnified so that the anatomical structures in the first and second set appear the same size. Which of the following statements is FALSE?
Answer: d
1. the resolution of the second set of images is better than the first set 2. the apparent noise in the second set of images is more pronounced than the first set 3. the patient dose of the first set of images is higher than the second set. a. 1&2 b. 1&3 c. 2&3 d. 1, 2, &3
Term
Definition
Which of the following is NOT directly proportional to mAs? a. the mean energy of the x-ray photons leaving the tube
Answer: a
b. the number of x-ray photons leaving the x-ray tube c. x-ray tube heating d. dose to the patient
Term
Definition
Which of the following parameters causes helical slices to be reconstructed so they overlap? a. table increment
Answer:
b. reconstruction interval
b
c. pitch d. collimation
Term
Definition
Which of the following is the expected result of a CT Number Calibration Test performed on a water phantom? Answer:
a. 0 +/- 3
a
b. 0 +/-5 c. 1000 +/-5 d. 100 +/-3
Term
Definition
On a conventional, or serial, Ct scan, if we want 5mm slices with 1mm of overlap, the talbe increment should be____mm. Answer:
a. 10
c
b. 6 c. 4 d. 1
Term
Definition
Which of the following parameters allows adjacent slices to be overlapped without increasing the dose to the patient? Answer:
a. reconstruction interval
a
b. slice thickness c. table increment d. pitch
Term
Definition
Which of the following can be changed retrospectively? 1. the slice thickness from an MDCT helical scan 2. the slice overlap from a single-row detector scanner helical scan
Answer:b
3. the slice thickness from a single row-detector scanner helical scan a. 1&3 b. 1&2 c. 2&3 d. 1, 2, &3
Term
Definition
Which of the following values for pitch would stretch the x-ray helix the most? a. 1.5
Answer:
b. 1.0
a
c. 0.8 d. 0.5
Term
Definition
The ____determines how penertrating the x-ray beam will be. a. kVp
Answer:
b. rotation time
a
c. mA d. pitch
Term
Definition
Which of the following would be used in a high resolution study of the temporal bones? a. reduced slice thickness
Answer:
b. reduced reconstruction FOV
d
c. sharp reconstruction filter d. all of the above
Term
Definition
Which of the following would be used to better visualize low contrast resolution? 1. decreased mAs Answer: d
2. sharp reconstruction filter 3. narrow window width a. 1 only b. 2 only c. 1 & 2 d. 3 only
Term
Definition
For a given distance of coverage, which of the following is TRUE? 1. as reconstruction FOV increases, patient dose increases
Answer: d
2. as pitch increases, patient dose decreases 3. as slice thickness increases, patient dose decreases a. 1 only b. 2 only c. 3 only d. 2&3
Term
Definition
_______the window _____will make the image appear darker so that the bony structures can be evaluated. a. increasing, width
Answer:
b. decreasing, level
d
c. decreasing, width d. increasing, level
Term
Definition
Follwoing the HIPAA guidelines, you may give a ptient's medical information to another employee: a. if it is in plain sight on the Ct console and the employee has already read it
Answer:c
b. if the employee is realated to the patient c. only if it is needed to do their job d. to joke about the patient's excessive weight
Term
Definition
If the mA of a 2 second brain scan is doubled and all other parameters are not changed the dose is: a. doubled
Answer:
b. unaffected
a
c. halved d. quadrupled
Term
Definition
Which of the following is the complete name of the laborator test known as PTT? a. thromboplastin time Answer: c
b. prothrombin time c. partial thromboplastin time d. partial prothrombin time
Term
Definition
Renal function refers to which of the following organs? a. gall bladder b. kidney
Answer: b
c. liver d. spleen
Term
Definition
In all states, patients are required by law to sign consent forms for the following reason: a. permission to admisister contrast
Answer:
b. permission to perform a surgical procedure
c
c. signed consent forms are not required by law in every state d. permission to administer sedation
Term
Definition
Which of the following values for prothrombin time are considered outside the normal range? 1. 12 sec
Answer:
2. 20 sec
d
3. 30 sec a. 1 only b. 2 only c. 3 only d. 2 & 3
Term
Definition
_____mm Hg is within the normal diastolic pressure range for adults. a. 40
Answer:
b. 80
b
c. 120 d. 140
Term
Definition
The result of which of the following lab tests may impact the decision to administer IV contrast media? a. BUN Answer:d
b. creatinine c. PT d. all of the above
Term
Definition
On a multi-row detector scanner, a radiation penumbra may be found: a. on every other slice
Answer:
b. only on the trailing edges of the slices
d
c. on every slice d. only on the first and last slices of the slice volume
Term
Definition
On a single-row detector scanner, which of the following does NOT decrease the patient dose? a. decreasing the scan time while leaving the mA constant
Answer: b
b. decreasing the slice thickness while covering the same anatomical region c. reformat the data instead of re-scanning d. increasing the pitch
Term
Definition
Which of the following is the correct action to take if the patient arrives with obvious head trauma, expecting a CT of the brain, but the paperwork requests a pelvic CT?
Answer:
a. perfom only a scan of the pelvis
b
b. request clarification from the ordering physician c. perform both exams d. perform only a scan of the brain
Term
Definition
During a CT scan, the patient must be monitored: a. visually and verbally
Answer:
b. occasionally
a
c. by a nurse d. by a pulse oximeter
Term
Definition
Which of the following does NOT minimize the radiation dose to the patient? a. decreasing the distance from the x-ray tube to the patient
Answer: a
b. filtration of the low energy photons from the x-ray beam c. increasing the pitch d. pre-patient collimation
Term
Definition
For x-ray radiation, which of the following is TRUE? a. 1 rem=1 rad
Answer:
b. 1 rem= 1 Gy
a
c. 1 rad= 1Gy d. 1 rad= 1Sv
Term
Definition
A normal pulse rate for an infant is _____BPM. a. 140
Answer:
b. 85
a
c. 60 d. 30
Term
Definition
The most important consideration in the care of an unconscious patient is to ensure that: a. air passages are clear
Answer:
b. the body temperature is decreased
a
c. fluids are maintained d. no medications are administered
Term
Definition
Which of the following statements is TRUE if the patient history was taken at the time of scheduling? a. a claustrophobic patient can arrive for the scan prepared with a prescription sedative
Answer: a
b. time can by saved the day of the exam by skipping the screening process c. if it has been determined that the patient has no prior illness or conditions, monitoring is unnecessary. d. all of the above
Term
Definition
The human embryo/fetus is most sensitive to radiation: a. in the second trimester b. in the first trimester
Answer:
c. equally in all trimesters
b
d. in the third trimester
Term
Definition
Which of the following could be the dose experienced by the pituitary from a typical CT brain scan? a. 9 rads
Answer:
b. 5 mGy
c
c. 2 rads d. 1 mGy
Term
Definition
If there is no overlap or gap between adjacent slices of a CT scan, CTDI __________MSAD. a. is less than
Answer:
b. equals
b
c. is much greater than d. is slightly greater than
Term
Definition
A normal adult has ______respirations per minute. a. 5-8
Answer:
b. 12-20
b
c. 20-30 d. 30-40
Term
Definition
A blood urea nitrogen level of ___mg/dl is considered outside the normal range. 1. 10
Answer:
2. 18
c
3. 32 a. 1 only b. 2 only c. 3 only d. 2&3
Term
Definition
Which of the following tests is NOT an indication of renal function? 1. BUN
Answer:
2. creatinine
c
3. PTT a. 1 only b. 2 only c. 3 only d. 2&3
Term
Definition
Which of the following conditions may be an indication NOT to use IV contrast media? a. previous serious reaction to contrast media used during another diagnostic procedure
Answer: d
b. allergy to iodine c. renal impairment d. all of the above
Term
Definition
Which of the following is NOT a typical indication of shock? a. grayish skin tone
Answer:
b. convulsive seizures
b
c. hypotension d. tachycardia
Term
Definition
Platelets are small: a. implants Answer:
b. detector elements responsible for captuing attenuated photons
c
c. cell fragments necessary for blood coagulation d. catheters used for administering contrast media
Term
Definition
Which of the following reduces patient dose at the expense of increasing the apparent noise in the image? a. kVp
Answer:
b. pitch
d
c. table increment d. mAs
Term
Definition
A 25 year old female is scheduled for a CT scan of the sinuses. She is not absolutely certain that she is not pregnant and it has been three weeks since her last menstrual period. Which of the following is the best course of action?
Answer: b
a. perform the exam immediately, while she is experiencing sinus problems b. psotpone the proceduer until she is more certain of her condition c. cancel the procedure indefinitely d. suggest she get an MRI instead
Term
Definition
Which of the following is a possible long-term effect of repeated exposure to radiation? a. cataracts
Answer:
b. cancer
d
c. decrease in life expectancy d. all of the above
Term
Definition
CPR must be administered to a cardiac arrest victim within a maximum of ______before there is a risk of brain damage. Answer:
a. 1
b
b. 4 c. 8 d. 12
Term
Definition
Which is NOT a standard infection control precaution to use with all patients? a. use of an N95 respirator
Answer:
b. wash hands after touching a patient
a
c. disposal of needle in sharps container d. wear gloves when starting an IV
Term
Definition
Which of the following statements is TRUE? a. respirators are not allowed in the CT suite b. pulse oximeters are allowed in the CT suite
Answer:
c. the patient should be removed from the CT suite to treat cardiac arrest
b
d. all of the above
Term
Definition
A patient about to get a scan of her sinuses may wear: a. eyeglasses so she can see the technologist
Answer:
b. a nose ring
c
c. her new belt with a large silver buckle d. earrings, to look her best
Term
Definition
Which of the following is TRUE regarding a radiation penumbra? 1. it occurs because the collimator is broken
Answer:
2. it is radiation that extends outside of the imaging region
c
3. it is accounted for in the calculation of the MSAD a. 1 only b. 2 only c. 2 &3 d. 3 only
Term
Definition
A creatinine level of 3.1 mg/dl indicates the: a. kidneys are not removing waste products from the urine Answer:b
b. patient is not a good candidate to receive IV contrast media c. value is below the normal range d. all of the above
Term
Definition
Making up the ARRT Standard of Ethics are the Code of Ethics which is ______, and the Rules of Ethics which are_______. Answer:
a. a law, variable depending upon the state you're in
c
b. a conduct guideline, variable depending upon the state you're in c. a conduct guidline, enforceable d. a law, recommended job descriptions
Term
Definition
When reviewing the images from a helical CT scan, a subtle, suspicious area of possible pathology is noticed. What could be done to better visualize the suspicious are WITHOUT increasing the dose to the patient?
Answer:
a. re-scan the region using thinner slices
c
b. re-scan the region using a lower pitch c. retrospectively reconstruct the slices so that they overlap d. all of the above
Term
Definition
Which of the following vital signs is considered abnormal? a. adult pulse of 75 BPM
Answer:
b. pediatric pulse of 110 BPM
c
c. adult blood pressure of 160/100 d. oral temperature of 97°
Term
Definition
To modify a standard CT protocol so that it is appropriate for children, which of the following should be decreased? Answer:
1. pitch
d
2. kVp 3. mAs a. 1 only b. 1 & 2 c. 1 & 3 d. 2 & 3
Term
Definition
Which of the following may result from exposing an embryo to x-ray radiation a. mental retardation
Answer:
b. miscarriage
d
c. deformities d. all of the above
Term
Definition
Which of the following is a result of injecting a hypertonic solution into the vascular space? a. there is a net movement of water into the vascular space
Answer: a
b. there is a net meovement of contrast media out of the vascular space c. there is a net movement of water out of the vascular space d. there is nothing noteworthy about injecting a hypertonic solution into the vascular space
Term
Definition
Which of the following is a common patient reaction to IV contrast media? a. warmth at the injection site
Answer:
b. headache
d
c. nausea d. all of the above
Term
Definition
Low osmolar contrast media: a. typically has the same concentration of particles as the blood
Answer:
b. typically has a higher concentration of particles compared to blood
c
c. tends to cause more adverse reactions than high osmolar contrast media d. is never used in CT
Term
Definition
Barium sulfate oral contrast media would be selected instead of iodonated oral contrast media because: 1. it passes through the GI tract more quickly
Answer:
2. the trauma patient may have a perforated bowel
d
3. the contrast media stays more dense in the distal GI tract a. 1 only b. 2 only c. 2&3 d. 3 only
Term
Definition
Which of the following may help to reduce adverse reactions resulting from the administration of IV contrast media? Answer:
a. use high osmolar contrast media
b
b. administer an antihistamine prior to the IV contrast injection c. increase the rate of injection d. all of the above
Term
Definition
Which of the following oral contrast agents is better for opacifying the distal small intestine? 1. an ionic iodinated contrast agent
Answer:
2. a non-ionic iodinated contrast agent
c
3. barium sulfate a. 1 only b. 2 only c. 3 only d. 1 & 2
Term
Definition
Iodinated IV contrast agents perfuse normal: a liver tissue
Answer:
b. brain tissue
a
c. thecal sac d. lymph nodes
Term
Definition
Which of the following is NOT a typical adverse reaction to oral contrast media used in CT? a. diarrhea
Answer:
b. abdominal cramping
d
c. flatulence d. hives
Term
Definition
A delay of about ____seconds after the start of the IV contrast injection should be used for a helical scan of the neck. Answer:
a. 20
b
b. 35 c. 50 d. 75
Term
Definition
If there is doubt regarding the sterility of the contrast media, the contrast media must be: a. shaken
Answer:
b. diluted
d
c. heated d. discarded
Term
Definition
The most common catheter size used in CT is_____gauge. a. 12 to 14
Answer:
b. 15 to 17
c
c. 18 to 22 d. 23 to 25
Term
Definition
Viscosity is a measure of a fluid's: a. atomic weight
Answer:
b. thickness
b
c. temperature d. injection rate
Term
Definition
The viscosity of IV contrast media can be reduced by: a. shaking
Answer:
b. stirring
d
c. aerating d. heating
Term
Definition
Why is the cephalic vein a less desirable site for injection than the basilic vein? a. it is usually a very small vein with poor blood flow
Answer:
b. the blood must transverse through the vessels in the head before reaching the heart
d
c. it is a deep vein and not easily catheterized d. flow may be impeded as the patient's arms are raised
Term
Definition
A difference in density of ______HU between the aorta and the inferior vena cava would indicate the nonequilibrium phase of enhancement Answer:
a. 43
c
b. 35 c. 25 d.8
Term
Definition
There substantial enhancement of the liver compared to tumors during the ______phase, but during the ______phase, there is the possibility of tumor enhancement, which may make hepatic tumors isodense with liver tissue.
Answer: b
a. bolus, equilibrium b. non-equilibrium, equilibrium c. non-equilibrium, bolus d. equilibrium, non-equilibrium
Term
Definition
Iv contrast agents used in CT increase the attenuation of the x-ray beam due to the concentration of _____in the agent. Answer:
a. iodine
a
b. glucose c. meglumine d. barium
Term
Definition
The definition of osmolality is the _____the contrast agent solution a. thickness of
Answer:
b. measure of dissociation of
c
c. concentration of molecular particles in d. rate of injection of
Term
Definition
The osmolality of plasma is ____mOsm/kg. a. 175
Answer:
b. 235
c
c. 285 d. 325
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