MIC CT Registry Q

Small focal spots make possible:
(1) thin slices
(2) high resolution
(3) low resolution

A) 1,2
B) 3 only
C) 1 only
D) 1,3

Most commands from the CT tech are received by the:

A) host computer
B) array processor
C) CT gantry
D) operator's console

What is the Anode target material out made of?

A) carbon fiber
B) tungsten
C) titanium
D) bismuth

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) 1,2,3
C) 3 only
D) 2 only

Which is TRUE regarding 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 3rd and 4th Generation CT systems

A) 1 only
B) 1,2
C) 1,2,3
D) 2,3

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 to the patient

A) 1 only
B) 3 only
C) 2,3
D) 2 only

For MDCT, the collimator selects the thickness of the x-ray beam which spreads over multiple rows of detectors. What determines the final slice thickness?

A) image recon
B) pitch
C) pre-patient collimation
D) prospective synchronization

True/False: MDCT collect information from multiple anatomical slices in each rotation of the x-ray tube.
True False

CT tube voltages ranges between ____ kV.

A) 80 - 120
B) 100 - 160
C) 70 - 100
D) 90 - 140

Which 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 body
(2) the molecular composition of the tissues through which they pass through
(3) the type of detector material used

A) 1,2,3
B) 3 only
C) 1 only
D) 1,2

Which statement is FALSE regarding occurrences after an x-ray photon penetrates the detector aperture?
(1) photon can pass through the detector unmeasured
(2) photon is converted completely into an electron
(3) the measured signal is enhanced by an amplifier

A) 1,2,3
B) 1 only
C) 2 only
D) 3 only

Which system component converts the projection attenuation data into the proper digital form for the array processor?

A) ADC
B) photodiode
C) array processor
D) host computer

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, high
C) high, low
D) low, low

___ allow(s) remote authorized individuals to connect to a server in a secure fashion using the routing infrastructure provided on a public network (ie internet).

A) DICOM
B) increased bandwidth
C) T1 lines
D) VPN

What is the purpose of the pre-patient collimator in MDCT?

A) increase voltage
B) reduce patient safety
C) slice thickness
D) reduce patient dose

CT consists of an anode and a cathode, which is positive and which is negative?

A) -, neutral
B) +, -
C) neutral, +
D) -, +

Which are NOT commonly used on today's commercially available CT Scanners?
(1) xenon detectors
(2) 4th Generation technology
(3) continuous rotation technology

A) 1,3
B) 1,2
C) 1,2,3
D) 2,3

The number of electrons that flow from the cathode to the anode in the tube is controlled by:

A) kVp
B) anode
C) mA
D) collimation

CT is commonly referred to as all of the following EXCEPT:

A) computerized axial tomography
B) digital subtraction angiography
C) computerized tomography
D) CAT-scan

Which is/are characteristic radiation?
(1) collision between an incoming electron and the nucleus of the target atom
(2) slowing down of an incoming electron due to the effect of passing close to the positive charge of the nucleus or target atom
(3) collision between an incoming electron and an inner-shell electron of a target atom

A) 1,2,3
B) 2,3
C) 1,2
D) 3 only

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) 2,3
B) 1,3
C) 1,2
D) 1,2,3

Which is a component NOT normally located in the gantry of a modern CT system?

A) array processor
B) x-ray tube
C) pre-patient collimator
D) solid state detector

Increased ___ will increase the likelihood that a given x-ray will penetrate a material.
(1) kV
(2) mA
(3) exposure time

A) 1 only
B) 1,2,3
C) 1,2
D) 2,3

Which is the standard that's used to achieve compatibility for image transfer between various imaging modalities viewing stations, and printers in a hospital?

A) PACS
B) T1
C) TCP/IP
D) DICOM

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 x-ray beam angle

A) 2 only
B) 1,2,3
C) 1 only
D) 1,2

What control does the operator have over the x-rays in a CT exam?

A) the phase and frequency of the x-rays can be adjusted
B) the temperature and color of the x-rays can be tuned
C) the volume and tone of the x-rays can be dialed
D) the energy level and quantity of the x-rays can be selected

The slip ring on continuous rotation CT scanners:
(1) prevents high voltage cables from winding up
(2) allows the exam to commence more rapidly
(3) eliminates the need for the reversal of gantry frame rotation

A) 1,2,3
B) 1,3
C) 2,3
D) 1,2

Which generation scanner did NOT use a fan beam?

A) 2nd Gen
B) 4th Gen
C) 1st Gen
D) 3rd Gen

What did the 1st Generation CT scanner use?

A) cone beam
B) square beam
C) pencil beam
D) fan beam

The patient table:

A) remains stationary throughout the exam once it is initially positioned
B) may move continuously during the scan
C) can never be positioned automatically by software due to safety precautions
D) only moves after each slice is completed

Which is NOT part of the CT tube?

A) filament
B) tungsten target
C) collimator
D) rotating anode

Breamsstrahlung radiation does NOT include:
(1) collision between an incoming electron and target atom's nucleus
(2) collision between an incoming electron and the target atom's inner shell electron
(3) slowing down of an incoming electron due to the effect of passing close to the target atom's positively-charged nucleus

A) 2 only
B) 1,2,3
C) 3 only
D) 1 only

Which is NOT a function of a PACS?

A) digital distribution of images
B) long-term data storage
C) image display for the radiologists
D) recon of the image from raw data

Which statement is FALSE regarding the collection of CT data?

A) the recon process used to create the image occurs in the array processor
B) the detectors measure x-rays which completely penetrate the patient
C) long scan times are more desirable because they average out motion artifacts
D) to collect the complete set of CT data, x-rays must be passed through the body at many different angles

The mA determines the:

A) attentuation of low energy photons
B) slice thickness
C) energy level of the x-ray photons
D) quantity of x-ray photons

Collimation:

A) limits the low energy x-ray photons and passes the high energy photons
B) is accomplish by physically blocking x-rays
C) affects scan time
D) is accomplished by electronically blocking x-rays

Which statement(s) 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 filament
(2) kV controls the energy level of the x-ray photons and mA controls the number of x-ray photons emitted from the x-ray tube
(3) although kV and mA affect the operation of the x-ray tube, the two have NO bearing on the image quality

A) 1,3
B) 1,2
C) 2,3
D) 1,2,3

Which statement(s) 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) 2,3
B) 1,3
C) 1,2
D) 1,2,3

X-rays are used in CT because:

A) they penetrate the body according to specific attenuation characteristics of each tissue
B) they are less harmful than the heating effects of microwave radiation
C) the FDA imposes no limit on the patient dose
D) they are easily produced by the high frequency generator

Scatter radiation is caused by:

A) x-ray generated spontaneously in the ambient atmosphere
B) improper patient positioning
C) deflections from the original trajectory of an x-ray photon through the patient
D) miscalibrated detector

The main purpose of the detector is to:

A) provide additional collimation
B) amplify signal
C) limit patient dose
D) capture x-ray photons and convert them to a measurable signal

The operator's console may include:
(1) monitor
(2) keyboard
(3) graphic input device
(4) Gantry

A) 1,3,4
B) 1,2,3
C) 2,3,4
D) 1,2,3,4

___ scanner design was the first to acquire 4 slices in a single rotation.

A) 3rd Gen
B) 4th Gen
C) continuous rotation
D) multi-row detector

X-rays are produced when fast moving electrons collide with a target material and ___ energy.

A) distribute
B) gain
C) maintain
D) lose

The cathode filament:

A) releases the x-ray photon
B) focuses x-rays onto the anode target
C) helps determine the size of the focal spot
D) lights up the tube for service

On a SDCT scanner, what technical factor determines the slice thickness?

A) pre-patient collimator
B) kVp
C) focal spot
D) post-patient collimator

X-rays are produced whenever fast-moving electron collide with any form of matter because it:
(1) splits into 2 x-ray photons of equal energy upon impact
(2) loses kinetic energy which is converted into the emission of an x-ray photon
(3) converts the electron it collides with into an x-ray photon

A) 1,2,3
B) 3 only
C) 1 only
D) 2 only

Which is TRUE regarding MDCT 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) 2,3
B) 1,2
C) 1,2,3
D) 1,3

Tube interscan delay time refers to:

A) the time between the end of one scan and the beginning of the next scan during which the tube will cool
B) a QA test performed daily by the CT Tech
C) the length of time required for the production of photons to begin after applying the tube voltage
D) the time required for the tube to make a complete 360 degree rotation

___ made helical imaging possible.

A) continuous rotation scanners
B) 3rd Gen
C) 4th Gen
D) multi-row scanners

Which technology do MDCT scanners employ?

A) 1st Gen
B) 2nd Gen
C) 3rd Gen
D) 4th Gen

Which CT scanner designs does NOT use an x-ray tube?

A) PET/CT
B) multi-row scanners
C) electron beam CT
D) 1st Gen

In a radiology department, a ___ is an example of a "client" on a network.
(1) CT scanner
(2) viewing console
(3) printer for Dx images

A) 1,3
B) 1,2,3
C) 1,2
D) 2,3

The enormous heat that builds up in the tube is caused by the:

A) intensity of the x-rays emitted from the tube
B) x-ray filter in the tube which absorbs the lower energy photons before they can enter the patient
C) collision of the electron beam with the tungsten target
D) electron beam between the cathode and anode

On a SDCT scanner, collimation:
(1) controls the slice thickness
(2) minimizes the patient dose
(3) reduces the detection of scatter radiation

A) 1 only
B) 1,2,3
C) 2 only
D) 3 only

___ is the mathematical process used by SDCT scanners to reconstruct CT images from raw data.

A) integration of the area under the curve
B) fourier transform
C) filtered back projection
D) weighted averaging

MDCT scanners capable of collecting 64 slices in a single rotation do NOT:

A) perform localizer scans
B) perform conventional CT scans
C) perform helical CT scans
D) use filtered back projection as their method of image reconstruction

The x-ray beam used in CT scanning is ___ the patient's tissues.
(1) reflected off of
(2) attenuated by
(3) generated by

A) 1,2,3
B) 3 only
C) 1 only
D) 2 only

A retrospective recon, in which the recon FOV is varied, uses:

A) more photons
B) image data
C) raw data
D) a reconstructed image in the SAG plane

CTA images come from ___ scan.
(1) conventional/serial
(2) helical
(3) localizer

A) 2,3
B) 1,3
C) 1,2
D) 2 only

The actual attenuation data measured by the detector from all projections during a scan is contained in the CT ___ data.
(1) image
(2) convoluted
(3) raw

A) 2 only
B) 1 only
C) 3 only
D) 1,2,3

Using ___ recon filter would decrease the appearance of noise in a CT image.
(1) no
(2) sharp
(3) smooth

A) 3 only
B) 2 only
C) 1,2,3
D) 1 only

A kernel is a:

A) type of detector
B) filter applied to the raw data
C) post-processing filter applied to image data
D) component of the x-ray tube

Iterative recon is:

A) a 2nd recon process performed after the initial recon in which a set of modified parameter is used
B) typically performed on helical image data, to generate image in orientations other than those that can easily be directly acquired with CT
C) a complex cycle of correction calculations applied during image recon in order to reduce noise in the image
D) the type of image recon method used in CT before MDCT scanners became available

From which of the following can the most Dx MPR be generated?
(1) stacked transverse images from a helical scan
(2) stacked transverse images from a conventional scan
(3) stacked localizer scans

A) 1 only
B) 2 only
C) 3 only
D) 1,2,3

A pixel is a:

A) range of gray levels on a CT image
B) single 3D volume element within a volume of anatomical data
C) bright artifact on film
D) single 2D picture element within the image plane

If an image matrix has 360 rows and 360 columns, how many pixels are there in the image?

Important clinical benefits of iterative recon include:
(1) ability to reduce radiation dose without compromising image quality
(2) no longer needing to perform MPR recons
(3) reduction in noise seen in the image

A) 1,2
B) 1,3
C) 2,3
D) 1,2,3

Which statement is FALSE regarding 3D SSD?

A) helical image data is well suited because there is minimal misregistration or gaps
B) the volume data is created by combining transverse, SAG, and COR recons
C) patient motion during the scan is detrimental to the quality of the 3D images
D) the tissue surface may be selected by using a threshold value equal to the tissue's CT number

A helical scan performed on a 64 slice MDCT scanner is recon'd with:

A) back projection
B) cone beam recon
C) no recon filter
D) simple recon because it is a single projection scan

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 the dual focal spot provide compared to an identical scanner with a single focal spot?
(1) #projections is doubled
(2) #rays in a single projection is doubled
(3) the patient dose is halved

A) 1,2,3
B) 3 only
C) 1 only
D) 2 only

A ___ scan uses only a single projection.
(1) conventional
(2) helical
(3) localizer

A) 1,2,3
B) 1,3
C) 2,3
D) 3 only

What does convolution do to the image quality when it is added to the back projection recon process?

A) improves contrast resolution by reducing scatter
B) increases the #projections thereby reducing streaking artifacts
C) normalizes the attenuation coefficients to ensure tissues are displayed with correct CT numbers
D) enhances important characteristics of attenuation profiles thus reducing streak and star artifacts

The ___ move(s) during a helical scan on a 3rd Gen scanner.
(1) x-ray tube
(2) patient table
(3) detector elements

A) 1,3
B) 1,2,3
C) 2,3
D) 1,2

Which is a recon technique applied to the raw data after the primary recon has already been accomplished?

A) VR
B) MIP
C) MPR
D) retrospective recon

A smooth, or low-pass, recon filter is typically NOT selected for a(n) ___ exam.

A) kidneys
B) liver
C) pituitary
D) IAC

Which is NOT an advantage of helical study compared to a conventional CT study?

A) can retrospectively reconstruct a slice at any arbitrary position
B) offers the best image quality for a brain exam
C) shorter total exam time
D) minimal anatomical misregistration sometimes caused by inconsistent breath-holding

An increase in ___ does NOT occur in the resulting images when applying a sharp, or high-pass, recon filter during the image recon of the raw data.
(1) contrast resolution
(2) edge enhancement
(3) the appearance of noise

A) 1,2,3
B) 1,3
C) 1 only
D) 1,2

Which utilizes convolution?
(1) 3D SSD
(2) fourier transform
(3) filtered back projection

A) 1,2
B) 1,3
C) 3 only
D) 2,3

___ yields an image that appears 3D but also shows anatomical details above and below the 3D surface.

A) MIP
B) MPR
C) VP
D) SSD

__ may have to be edited from the data set to get a Dx MIP of a CTA.

A) bones
B) vessels of interest
C) iodinated contrast media
D) air

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) MPR
B) VR
C) MIP
D) 3D SSD

True/False: The amplified electrical signal obtained from the detectors must be digitized.
True False

True/False: Digital CT images are numerical representations of cross-sectional anatomy.
True False

True/False: Digital signals may be formed by sampling analog signals at discrete time intervals.
True False

MPR recons are performed on:
(1) image data
(2) raw data
(3) attenuation data

A) 1,3
B) 1,2,3
C) 1 only
D) 1,2

___ allows helical data to be converted into planar raw data.

A) retrospective recon
B) cone beam recon
C) interpolation
D) convolution

In the diagram, which x-ray tube position will produce a lateral localizer image?

Which may occur during the interscan delay of a conventional scan on a continuous rotation scanner?
(1) table position incremented
(2) tube continues to rotate in the same direction as during the scan
(3) tube assembly makes a 360* rotation

A) 2,3
B) 1,2,3
C) 1,3
D) 1,2

On a 3rd Gen SDCT scanner, if there are 715 detectors and there are 900 projections in a full scan, how many samples of attenuation data are collected for the raw data of a single slice if the scan calls for an overscan of 400* rotation?

The ___ determines the intensity of the laser beam in a laser camera.

A) all of the above
B) intensifying grid
C) pixel values in the image data
D) magnifying power of the lens

The pencil thin section of the x-ray fan beam that strikes a single detector is called:

A) line
B) projection
C) ray
D) view

3D SSD displays are performed on CT:
(1) image data
(2) raw data
(3) attenuation data

A) 2 only
B) 1 only
C) 1,2,3
D) 3 only

Which is TRUE regarding the slice thickness of an image recon'd from a helical scan?
(1) on a MDCT scanner, the thickness is equal to the beam collimation
(2) on a SDCT scanner, the thickness can be varied retrospectively
(3) on a SDCT scanner, the thickness is equal to the beam collimation

A) 1 only
B) 1,2,3
C) 2 only
D) 3 only

MIP images:

A)  can NOT be run in a cine loop
B) do NOT demo detail beneath the brightest pixel
C)  are most frequently used for visualizing air-filled spaces
D)  are most accurate when a large volume is selected

Which determinants of CT image quality is responsible for how grainy or speckled a CT image appears?

A) noise
B)  contrast
C)  linearity
D)  resolution

An increase in ___ will result in hardening of the x-ray beam.
(1) tissue density
(2) kVp
(3) tissue thickness

A) 2,3
B) 1,2,3
C) 1,2
D) 1,3

Which are possible results of partial voluming?
(1) decreased edge sharpness
(2) increased resolution
(3) misleading CT numbers

A) 1,2,3
B) 2,3
C) 1,3
D) 1,2

Resolution is NOT dependent on:
(1) matrix size
(2) recon FOV
(3) scanned FOV

A) 2 only
B) 3 only
C) 1,2,3
D) 1 only

Which is NOT directly proportional to mAs?

A) #x-ray photons leaving the x-ray tube
B) the mean energy of the x-ray photons leaving the tube
C) patient dose
D) x-ray tube heating

Which technique has the highest patient dose assuming all other parameters remain the same?

A) mA=400, time=1sec
B) mA=150, time=3sec
C) mA=100, time=4sec
D) mA=200, time=2sec

Which will result in an increased voxel size?
(1) decreased recon FOV
(2) increased matrix
(3) increased slice thickness

A) 3 only
B) 1 only
C) 1,2,3
D) 2 only

Which is the conversion equation from CT Number to Hounsfield unit?

A) CT number = HU
B)  CT number = 2 x HU
C)  CT number = 0.5 x HU
D) CT number = HU^2

If the radiologist requires 2mm thick contiguous slices through the pituitary, and 2.4cm of coverage, how many slices are needed?

CT numbers ___ would appear black if a window width of 400 and window level of -100 are used.

If a recon FOV of 32cm and a 512x512 matrix are used, the pixel size is ___mm

Which is a reason to increase pitch?
(1) greater volume of anatomy can be covered in a given time
(2) radiation dose to patient can be increased
(3) given volume of anatomy can be covered faster

A) 2,3
B) 1,2
C) 1,3
D) 1,2,3

Which would be used to better visualize low contrast resolution?
(1) decreased mAs
(2) sharp recon filter
(3) narrow window with

A) 3 only
B) 1 only
C) 2 only
D) 1,2,3

If a thin slice is used, which would help reduce the apparent image noise?

A) increasing kVp
B) increasing pitch
C) increased mAs
D) decreasing mAs

A set of images is recon'd with 150mm recon FOV. Keeping all other parameters constant, a 2nd set of images is recon'd with a 300mm recon FOV, and then magnified so that the anatomical structures in the 1st and 2nd set appear the same size. Which statement(s) is FALSE?
(1) the resolution of the 2nd set is better than the 1st set
(2) the patient dose of the 1st set of images is higher than 2nd set
(3) the apparent noise in the 2nd set is more pronounced than the 1st set

A) 1 only
B) 2 only
C) 3 only
D) 1,2,3

The ___ determines how penetrating the x-ray beam will be.

A) table increment
B) kVp
C) pitch
D) mAs

The smallest object that can be resolved if a recon FOV of 24cm and a 512x512 matrix are used is ___mm.

A) 0.5
B) 1.2
C) 0.47
D) 1

Which parameter(s) affects the contrast of an image?

A) mAs
B) pitch
C) slice thickness
D) kVp

Which pitch value would stretch the x-ray helix the most?

A) 2.0
B)  0.5
C) 1.2
D)  1.5

There are ___ total pixels in a 1024x1024 matrix.

A) 1,048,576
B) 104,857
C) 2,048
D) 2,097,152

True/False: For a given distance of coverage, as recon FOV increases, patient dose increases.
True False

True/False: For a given distance of coverage, as slice thickness increases, patient dose decreases.
True False

True/False: For a given distance of coverage, as pitch increases, patient dose decreases.
True False

True/False: Magnification requires raw data.
True False

True/False: Increasing magnification increases resolution.
True False

True/False: Magnification decreases the size of displayed anatomy.
True False

Compared to a CT scan protocol without iterative recon applied, when using iterative recon, which scan parameter is reduced?

A) mAs
B) kVp
C) time
D) pitch

A CT Number Calibration Test should be performed:

A) annually
B) monthly
C) daily
D) weekly

___ the window ___ will make the image appear darker so that bony structures can be evaluated.

A) increasing, level
B) decreasing, width
C) decreasing, level
D) increasing, width

Which is the expected result of a CT Number Calibration Test performed on a water phantom?

A) 0 ± 3
B) 100 ± 5
C) 0 ± 5
D) 1000 ± 3

___ affects the CT number of water.

A) table increment
B) no imaging parameter
C) pitch
D) slice thickness

Which parameter allows adjacent slices to be overlapped without increasing patient dose?

A) table increment
B) reconstruction interval
C) slice thickness
D) pitch

Which can be changed retrospectively?
(1) slice thickness from an MDCT
(2) slice overlap from a SDCT
(3) slice thickness from a SDCT

A) 1 only
B) 1,2,3
C) 1,2
D) 2,3

Which would be used in a high resolution study of the temporal bones?
(1) reduced slice thickness
(2) reduced recon FOV
(3) sharp recon filter

A) 1 only
B) 3 only
C) 1,2,3
D) 2 only

The ability to scan a moving organ without seeing motion artifacts on the images is an example of an exam with high:

A) temporal resolution
B) linearity
C) spatial resolution
D) contrast resolution

On a conventional CT scan, if we want 5mm slices with 1mm overlap, the table increment should be ___ mm.

A) 3
B) 4
C) 1
D) 2

On MDCT, the final recon'd slice thickness is determined by the:

A) #detector rows and the detector size whose attenuation data gets combined
B) pitch
C) collimation
D) recon interval

Which parameter is responsible for partial voluming?

A) no imaging parameter
B) pitch
C) table increment
D) slice thickness

The distance that the table travels between slices is called ___.

Which parameter causes helical slices to be recon'd so they overlap?

A) slice thickness
B) table increment
C) pitch
D) recon interval

Which does NOT occur when recon FOV is decreased?
(1) spatial resolution is increased
(2) pixel size is increased
(3) noise is increased

A) 2
B) 1 only
C) 1,2,3
D) 3 only

If a calcification with a CT number of +300 appears pure white on an image, which could be the window settings selected?
(1) WL = 0, WW = 500
(2) WL = +300, WW = 500
(3) WL = +100, WW = 300

A) 2 only
B) 1 only
C) 1,3
D) 1,2,3

A BUN of ___ mg/dl is considered outside the normal range.
(1) 10
(2) 18
(3) 32

A) 1,2,3
B) 2 only
C) 1 only
D) 3 only

To modify a standard CT protocol so that it is appropriate for children, which parameter(s) should be decreased?
(1) pitch
(2) kVp
(3) mAs

A) 2,3
B) 3 only
C) 1 only
D) 1,3

Which does NOT minimize the patient dose?

A) decreasing distance between x-ray beam and patient
B) pre-patient collimation
C) filtration of low energy photons from the beam
D) increasing pitch

Air in the pleural space causes the lung to collapse, which is termed:

A) empyema
B) pleural effusion
C) pneumothorax
D) hemothorax

Which medical device is most often used in oxygen delivery?

A) ETT tube
B) bi-pap
C) nasal cannula
D) tracheostomy tube

True/False: A pulse oximeter works by passing a beam of red and infrared light through the capillary bed.
True False

True/False: Normal O2 saturation is 85-100%
True False

Which does NOT test for renal function:

A) GFR
B) BUN
C) creatinine
D) PTT

The most sensitive trimester for a developing fetus/embryo is:

Platelets are small:

A) small pieces of cells that help create RBCs
B) cell fragments necessary for kidney cleaning
C) cell fragments necessary for cloating
D) cell fragments used in bile production

A creatinine level of 3.1 mg/dl indicates the:
(1) kidneys are not removing waste products from urine
(2) value is above the normal range
(3) contraindicated for IV contrast injection

A) 2,3
B) 2 only
C) 3 only
D) 1 only

True/False: The patient should be removed from the CT suite to treat cardiac arrest.
True False

Which PT are considered outside the normal range?
(1) 8s
(2) 18s
(3) 25s

A) 1,2,3
B) 1 only
C) 1,2
D) 2,3

True/False: A claustrophobic patient can arrive for the CT scan prepared with a prescription sedative.
True False

True/False: Monitoring patient during a scan or procedure is unnecessary if prior history or condition does not indicate the need for monitoring.
True False

If the mA of a 2sec brain scan is doubled and all other parameters are constant, the dose is:

Renal function refers to which organ?

Which reduces patient dose at the expense of increasing apparent noise?

A) pitch
B) mAs
C) kVp
D) table increment

During a CT scan, the patient must be monitored:

A) visually and verbally
B) sometimes
C) by RN
D) with a pulse oximeter

___ offers standardized lab values indicating the blood's ability to coagulate for patients taking anticoagulant medications.

A) PTT
B) INR
C) BUN
D) PT

When reviewing the images from a helical scan, a subtle suspicious area of possible pathology is noticed. What could be done WITHOUT increasing patient dose?
(1) re-scan the region using thinner slices
(2) retrospectively reconstruct the slices so that they overlap
(3) repeat scan but decrease pitch

A) 1,2,3
B) 1 only
C) 2 only
D) 3 only

True/False: Metformin has the same precautions as Glucophage, Glucovance, and Glucagon.
True False

Which is NOT typical indication of shock?

A) hypotension
B) tachycardia
C) seizures
D) grayish skin tone

CPR must be administered to a cardiac arrest victim within a maximum of ___ minute(s) before there is risk of brain damage.

___ mmHg is within the normal range of diastolic pressure for adults.
(1) 60
(2) 80
(3) 90
(4) 100

A) 1,3,4
B) 1,2,3
C) 2,3,4
D) 1,2,4

The most important consideration in the care of an unconscious patient is to ensure the ___ are clear and open.

What is the normal adult respiration per minute range?

A) 10-25
B) 25-50
C) 12-20
D) 15-30

Which lab tests often indicates the necessity for a CTA or NM to rule out pulmonary embolism?

What is the normal O₂ blood saturation?

A) 85-99%
B) 75-85%
C) 95-100%
D) 90-96%

Which vital sign is considered abnormal?

A) adult BP of 165/98
B) adult pulse of 85 bpm
C) rectal temperature of 99.5*F
D) pediatric pulse of 140 bpm

The ARRT Code of Ethics is considered a ___, while the Rule of Ethics is a ___.

A) guideline, changeable per state
B) law, guideline
C) conduct guideline, enforceable
D) guideline, non-liable

Which is a good effective dose estimate for a CT Head scan?

A) 2 mSv
B) 0.2 mSv
C) 20 Gy
D) 0.3 mSv

What does the lab test PTT stand for?

Which lab tests should be considered before administering IV contrast?
(1) BUN
(2) GFR
(3) creatinine
(4) PT

A) 1,2,3,4
B) 1,2
C) 2,3,4
D) 1,2,3

In a normal EKG, the ___ wave represents atrial contraction.

A) R
B) QRS
C) P
D) S

ON a MDCT scanner, a radiation penumbra may be found:

A) on every other slice
B) only on the trailing edges of the slices
C) on every slice
D) on 1st and last slices of the slice volume

Which technique minimizes the patient dose in a coronary calcium scoring exam?

A) prospective synchronization
B) no synchronization
C) retrospective synchronization
D) decreasing pitch

Which radiation dose measurement accounts for helical studies on MDCT scanners and considers the total volume of irradiated tissues?

A) CTDIvol
B) CTDI
C) DLP
D) MSAD

A normal pulse rate for an infant is ___ bpm.

A) 80
B) 200
C) 170
D) 90

What are the radiation shields used in CT made out of?
(1) tungsten
(2) lead
(3) bismuth

A) 1,3
B) 1 only
C) 3 only
D) 2 only

What should be done if extravasation is noticed at the injection site?

A) apply ice and continue exam
B) apply a heat compress while injection continues
C) immediately stop injection
D) slap infiltrated area to get it working

Which phase of IV contrast enhancement will occur first?

A) equilibrium, non-equilibrium, bolus
B) non-equilibrium, equilibrium, bolus
C) bolus, non-equilibrium, equilibrium
D) bolus, equilibrium, non-equilibrium

Which oral contrast is better for opacifying the distal small intestine?
(1) barium sulfate
(2) non-ionic iodine
(3) ionic iodine

A) 1,2,3
B) 1,2
C) 2 only
D) 1 only

The definition of osmolality is the ___ the contrast agent solution.

A) measure of dissociation of
B) concentration of molecular particles in
C) thickness of
D) rate of injection of

When a contrast agent is injected directly into the joint space it is termed:

A) intrathecal
B) intravenous
C) intraarticular
D) intracranial

Which characteristics of an IV contrast affects patient tolerance?
(1) iodine concentration
(2) viscosity
(3) osmolality

A) 3 only
B) 1 only
C) 1,2,3
D) 2 only

An IV contrast media viscosity can be reduced by ___.

The heating unit on a power injector is for ___ of the contrast agent.

A) increasing the viscosity
B) increasing the iodine concentration
C) decreasing the viscosity
D) decreasing osmolality

A difference of ___ HU between the aorta and IVC would indicate the non-equilibrium enhancement phase.

A) 15
B) 35
C) 45
D) 25

A delay about ___ sec after the start of IV injection should be used for a CT Chest exam.

A) 30
B) 40
C) 50
D) 20

Iodine oral contrast would be selected instead of barium sulfate because:
(1) it passes through GI more quickly
(2) the trauma patient may have a perforated bowel
(3) the contrast stays more dense in the distal GI tract

A) 1,2,3
B) 1,2
C) 1 only
D) 3 only

The most common gauge range of IV catheter used in CT is ___.

If there is doubt regarding the sterility of the contrast media, the contrast should be ___.

An indication of IV contrast injection is to rule out:
(1) mastoiditis
(2) meningioma
(3) sinusitis
(4) Grave's disease

A) 1,2
B) 2,3
C) 1,2,3,4
D) 2 only

The osmolality of plasma is ___ mOsm/kg.
(1) less than LOCM at 285
(2) less than LOCM at 300
(3) less than HOCM at 285
(4) less than HOCM at 400

A) 3 only
B) 1,3,4
C) 1 only
D) 2 only

True/False: The standard peripherally inserted central catheter, like those used for chemotherapy, are required for CT IV contrast studies.
True False

A delay of about ___ sec after the start of IV contrast injection should be used for a CT Neck.

A) 90
B) 35
C) 50
D) 30

True/False: According to ACR guidelines, under no circumstances should IV contrast be administered to a pregnant patient.
True False

True/False: According to ACR guidelines, IV contrast may be administered when it is not prudent to wait to obtain the clinical information until after the pregnancy.
True False

True/False: According to ACR guidelines, IV contrast may be administered if the clinical information obtained will affect the care of the patient and fetus during pregnancy.
True False

What is the appropriate care to give to a diabetic patient?
(1) if the patient is using Metformin, advice them to stop its use 48hrs before IV contrast injection.
(2) if the patient is using Metformin, advise them to resume its use 48hrs after IV contrast administration only after kidney function has been reassessed and determined to be normal
(3) if IV contrast is required, use LOCM

A) 1,3
B) 1,2,3
C) 2,3
D) 1,2

Which may help reduce adverse reactions resulting from IV contrast injection?
(1) use HOCM
(2) increase flow rate
(3) administer an antihistamine prior to the exam

A) 1,2,3
B) 3 only
C) 2 only
D) 1 only

To best visualize the stomach wall, what should the patient drink last?
(1) water
(2) iodine
(3) barium sulfate
(4) CO₂

A) 1,2,4
B) 1 only
C) 1,2
D) 2,3

There is significant 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.

A) equilibrium, non-equilibrium
B) bolus, equilibrium
C) non-equilibrium, bolus
D) non-equilibrium, equilibrium

Exams to rule out ___ would indicate the need for IV contrast in the chest.
(1) pneumothorax
(2) hilar mass
(3) aortic dissection

A) 3 only
B) 2,3
C) 1,2,3
D) 1,3

The typical scan delay for a pancreas study is:

A) 70-80 sec
B) 80-90 sec
C) 8-9min
D) 50-60 sec

Why is the cephalic vein a less desirable site for injection than the basilic vein?

A) the blood has to travel through the head before reaching the heart
B) it's a deep vein and hard to find
C) it's a small vein with poor blood flow
D) the flow is impeded with the patient's arms raised

How long does it take to inject 150 mL with a flowrate of 2cc/sec?

A) 50 sec
B) 60 sec
C) 75 sec
D) 80 sec

Viscosity is a measure of a fluid's ___.

A) thickness
B) temperature
C) flow rate
D) concentration

Which is a result of injecting a hypertonic solution into the vascular space?

A) contrast resolution
B) there is net movement of water out of the vascular space
C) there is net movement of water into the vascular space
D) there is no net movement out or into the vascular space of contrast or water

The portal venous phase occurs about ___ after IV contrast injection.

A) 50-60 sec
B) 60-90 sec
C) 70-80 sec
D) 80-90 sec

An injection rate of ___ cc/sec will maintain a dense bolus of IV contrast for a CTA exam and will be tolerated by most patients.

A) 1-2
B) 4-5
C) 5-6
D) 2-3

Iodinated IV contrast perfuse normal:
(1) liver
(2) brain
(3) lymph
(4) kidney

A) 1,2
B) 2,3
C) 1,2,3,4
D) 1,4

Which is associated with a bi-phasic study of the liver?
(1) using two contrast injection rates
(2) having 2 images per slice position
(3) lesion differentiation with arterial and portal venous blood supplies
(4) arterial occurs in the equilibrium phase, while portal venous happens during the non-equilibrium phase

A) 1,2,3,4
B) 2,3
C) 2,3,4
D) 1,2,4

A CT Brain exam to visualize MS plaques may be made more sensitive by using ___ delay after the contrast injection.

A) 15 min
B) 8-9min
C) 45 min
D) 2-5min

Low osmolar contrast media:
(1) typically has the same concentration of particles as plasma
(2) typically has the higher concentration of particles than plasma
(3) tends to cause more adverse reaction than HOCM
(4) is the preferred contrast type for diabetics over HOCM

A) 2,3,4
B) 2,4
C) 2,3
D) 1,3,4

The hepatic arterial phase occurs about __ sec after IV contrast injection.

A) 5-20
B) 40-60
C) 50-70
D) 20-40

Which is NOT a typical adverse reaction to oral contrast?

A) gas
B) hives
C) diarrhea
D) abdominal cramping

What type of "negative" contrast is administered rectally for virtual colonoscopy exams?

A) water
B) CO2
C) iodine
D) barium sulfate

Which statement is TRUE regarding barium sulfate contrast used in CT exams?

A) it's completely different than that used in conventional radiology
B) it's exactly the same as that used in conventional radiology
C) less concentration is used for CT than for conventional radiology
D) the same concentration is used in conventional radiology

The contrast between a lesion and the surrounding tissue may ___ following injection of contrast media.
(1) improve
(2) remain unchanged
(3) be degraded

A) 1 only
B) 3 only
C) 2 only
D) 1,2,3

Contrast agents containing barium sulfate:
(1) enhance structures because they are absorbed into the blood stream
(2) enhance structures because they are absorbed through the small intestine
(3) remain unchanged as they travel through the body

A) 1,2
B) 2,3
C) 1,3
D) 3 only

Which types of contrast has NO application for a CT T-Spine?
(1) oral
(2) IV
(3) intrathecal

A) 1 only
B) 2 only
C) 1,2,3
D) 3 only

In which studies might cranial nerve XI be visualized?

A) lumbar spine
B) soft tissue neck
C) supratentorium
D) IAC

In order to generate a 3D SSD rendering of the hips, the ___ data is used directly by the 3D recon software.

A) image
B) projection
C) raw
D) unrecon'd

Which is the appropriate range of coverage for a coronal sinus study?

A) from IACs to ethmoid sinus
B) from anterior aspect of frontal sinus to dorum sella
C) from clivus to anterior clinoid process
D) from spheniod sinus to 4th ventricle

Which is NOT a reason for using thinner slices in the posterior fossa compared with the more superior regions of the brain?
(1) improve spatial resolution
(2) decrease patient dose
(3) reduce streak artifacts

A) 3 only
B) 1,3
C) 1 only
D) 2 only

A localizer image in which orientation(s) should be used to set up axial slices so that they can be parallel to the plane of a specific lumber disk?

A) oblique
B) transverse
C) lateral
D) AP

Which is TRUE regarding CT spine exams?
(1) IV contrast is usually not needed to r/o herniated disk(s)
(2) the entire t-spine is not routinely scanned with transverse CT slices
(3) SAG and COR images of an adult spine may not be directly collected from a CT scan

A) 1,2,3
B) 1,2,3
C) 2,3
D) 1,2

Which is NOT an indication of a herniated disk?
(1) hypertrophy of the inferior articulating process and lamina
(2) deformity of the posterior disk border
(3) displacement of epidural fat

A) 1 only
B) 1,2
C) 1,2,3
D) 1,3

Which window settings provides the best tissue differentiation of the soft tissues of the supratentorium?

A) WW = 2500, WL = 350
B) WW = 300, WL = 60
C) WW = 1000, WL = 200
D) WW = 100, WL = 30

On a CTA lower extremity to assess atherosclerosis, coverage should extend from ___ to ___.

What is the primary reason to have a patient phonate the letter "e" during a CT larynx exam?

A) closes the pyriform sinuses
B) defines epiglottis better
C) distends laryngeal ventricles
D) demos vocal cord mobility

Which combos of scanning parameters is best for evaluating abnormalities within the petrous pyramids of the temporal bones?

A) algorithm = standard, WW = 300, slice = 0.5-2mm
B) algorithm = soft, WW = 300, slice = 0.5-2mm
C) algorithm = sharp, WW = 2500, slice = 0.5-2mm
D) algorithm = standard, WW = 2500, slice = 4-8mm

Which should NOT be part of a CT brain perfusion exam?

A) do not restrain patient's head during exam
B) multiple scans performed every 1-2sec for about 1min
C) low dose protocol
D) done with IV contrast

CT brain perfusion: 

A) 75-85%
B) replaces the need for CTAs
C) is typically performed to evaluate stroke
D) evaluates blood flow through the major vessels

Which is necessary to quickly and accurately Dx stroke?
(1) eval for ischemic but viable tissue
(2) eval for vascular occlusion
(3) establish if there is an intracranial hemorrhage

A) 1,2,3
B) 1 only
C) 2 only
D) 3 only

Which is FALSE about a CT Runoff exam?

A) coverage should extend from upper abdominal aorta/diaphram to popliteal artery bifurcation
B) spatial resolution of CTA exceeds MRA
C) patient should be positioned supine and feet first
D) flow rate = 4ml/sec

Indications for CT Head include:
(1) trauma
(2) stroke
(3) MS

A) 1,3
B) 2 only
C) 2,3
D) 1,2

Which is NOT a location where one would expect to find CSF?
(1) subarachnoid space
(2) 4th ventricle of the brain
(3) subdural space

A) 3 only
B) 1,2
C) 2,3
D) 1,3

Which scanning plane is best for evaluating the anatomical relationship between pituitary and sella turcica?

A) transverse
B) COR
C) SAG
D) soft tissue neck

Which would NOT enhance during the 1st several minutes of a post-contrast CT Neck?

A) capillary beds
B) vascular lesions
C) lymph nodes
D) jugular vein

From the ___ above and below the disk space should be scanned if only 1 intervertebral disk space was of interest.

A) pedicle
B) apophyseal joint
C) superior articular process
D) spinous process

What CT exam will cranial nerve VII be seen?

A) supratentorium
B) IACs
C) soft tissue neck
D) C-spine

If we want to generate a Dx 3D SSD of the C-spine, how should the scan be performed?

A) at a single angle and no gaps through the affected regions
B) with large gaps between slices
C) at various angles to cut out the streaking artifacts from teeth
D) at orthogonal orientations through affected regions

What can be done to reduce the lordotic curve in a CT L-spine exam?

For CT brain exams, the reference lines for axial slices are:
(1) crantomeatal line
(2) infraorbitomeatal line
(3) orbitomeatal line

A) 1,2,3
B) 1,2
C) 2,3
D) 1,3

To compensate for increased noise when reducing slice thickness, what and how should that parameter be varied?

For which condition of the brain should IV contrast NOT be administered?

A) evaluation of mass
B) suspected atrophy
C) aneurysm evaluation
D) recurrent headaches

For a routine CT Pelvis, what gantry tilt is used?

For CT Pelvis, from __ to __ should be scanned.

A) 12th rib, symphysis pubis
B) iliac crest, symphysis pubis
C) L-5, symphysis pubis
D) T-12, iliac crest

Which window setting is best for bone window of a CT Pelvis?

A) WW = 1100, WL = 100
B) WW = 2000, WL = 350
C) WW = 100, WL = 30
D) WW = 200, WL = 150

Which is a reason for inserting a tampon into the vagina for a CT Pelvis?

A) eliminates for oral contrast
B) helps visualize the vaginal canal
C) provides a high temperature on the image
D) eliminates need for IV contrast

Which is NOT recommended for a screening CT colonoscopy exam?
(1) both prone and supine positioning
(2) post-processing to visualize inside surface of bowel
(3) 200 mAs

A) 1,2
B) 1,3
C) 3 only
D) 2,3

TRUE/FALSE: A high calcium scoring is evidence of stenosis.
True False

In order to assess cardiac function, the ___ is evaluated.

A) left atrium
B) right atrium
C) right ventricle
D) left ventricle

The ___ view is used to evaluate cardiac function.

A) axial
B) 2 chamber long axis
C) 4 chamber long axis
D) short axis

Normal ejection fraction is greater than ___%

A) 60
B) 90
C) 70
D) 80

A CT urogram requires ___ of water to be consumed within ___ of the exam.

A) 1 qt, 45min-1hr
B) 2 qt, 45min-1hr
C) 1 L, 30-45min
D) 2 qt, 3hr

Which window settings is best for a CT Liver exam?

A) WW = 200, WL = 150
B) WW = 300, WL = 60
C) WW = 140, WL = 60
D) WW = 2500, WL = 350

The result of the bifurcation of the abdominal aorta is the left and right ___ arteries.

A) femoral
B) quadriceps
C) popliteal
D) common iliac

TRUE/FALSE: The left lobe of the liver is more anterior than the right and caudate lobe, while the caudate lobe is more medial than the right lobe.
True False

Which affects the severity of the metal artifacts?
(1) quantity, composition and shape of the metal
(2) number of data sampling points
(3) slice thickness

A) 1,2
B) 1 only
C) 1,3
D) 1,2,3

Which may occur if the patient's arms are not raised during a CT Chest with a 33cm scan FOV?
(1) beam hardening
(2) cone beam artifact
(3) out-of-field artifact

A) 1,3
B) 3 only
C) 1,2
D) 2,3

A(n) ___ artifact can be created when attempting to correct for a cupping artifact by applying a correction algorithm too aggressively to the data for a head image. This results in the ___ of the image appearing too bright.

A) capping, edges
B) edge gradient, center
C) capping, center
D) edge gradient, edges

CT x-ray tube arcing can occur because of ___ the x-ray tube.
(1) impurities in the oil outside
(2) tungsten solids in the oil inside
(3) tungsten gas inside

A) 2,3
B) 1,2
C) 1,3
D) 1,2,3

Which will have the least likelihood of producing edge gradient artifacts?

A) thick slices with full scan
B) thick slices with partial scan
C) thin slices with partial scan
D) thin slices with full scan

___ in the image is a possible manifestation of patient motion.
(1) ghosting
(2) blurring
(3) streaks

A) 1,3
B) 1 only
C) 2 only
D) 1,2,3

On a CT Brain, a cupping artifact would appear brighter:

A) at the periphery of the brain
B) at the anterior and posterior aspects of the brain
C) in the center of the brain
D) immediately around dense structures

A cone beam artifact may look like stars:

A) from all structures with high HU
B) at the center of the image
C) coming from structures around the edge of the image
D) coming from cone-shaped structures

A CT artifact is:

A) always a reason to call for service
B) used to time the contrast injection
C) an image anomaly
D) parameter used to control image brightness

Beam hardening refers to the increase in the:
(1) average beam energy
(2) # of photons reaching the detectors
(3) # of low energy photons reaching the detectors

A) 1 only
B) 1,3
C) 2 only
D) 3 only

Which would reduce noise?

A) increased mAs and kVp with sharp filter
B) increased x-ray tube to patient distance, same kVp and mAs
C) increased window widths, decreased pitch, same mAs
D) increased window widths, mAs, and slice thickness

The service engineer should NOT be notified about:
(1) consistent circle artifacts
(2) frequent bad streaks throughout entire scan
(3) frequent bad streaks on the inferior of the head scans

A) 2,3
B) 1,3
C) 1,2,3
D) 3 only

Which strategies minimizes beam hardening artifacts from dense contrast media?
(1) diluted contrast
(2) scan with a slight delay
(3) scan caudiocranial

A) 2,3
B) 1,2
C) 1,3
D) 1,2,3

Which would display the greatest amount of partial volume artifact?

A) 5mm from 100 slices
B) 10mm from 20 slices
C) 5mm from 20 slices
D) 2mm from 20 slices

Which would increase severity of edge gradient effect?
(1) scanner with a small aperture
(2) scanner with a low data sampling rate
(3) using thin slices

A) 1,2,3
B) 3 only
C) 2 only
D) 1 only

Which strategies will eliminate a ring artifact?

A) recalibration of detector elements
B) increase technique
C) removal all metal
D) increase matrix

Which could result from beam hardening?
(1) CT # inaccuracies
(2) cupping artifacts
(3) streaking

A) 1,2,3
B) 2,3
C) 1,3
D) 1,2

What causes cupping effect?

A) central tissues are not penetrated by the beam
B) the mean energy of the photons that comprise the beam is lowered
C) interface between tissues with different densities causes the high energy photons to be absorbed
D) attentuation of low energy photons

What causes 2 parallel lines to appear on a localizer image?

A) cone beam effect
B) two faulty detector elements
C) reconstruction algorithm error
D) tube arcing

What would decrease beam hardening?
(1) increasing kVp
(2) increasing mAs
(3) increasing slice thickness

A) 1,3
B) 1,2
C) 1 only
D) 1,2,3

A(n) ___ artifact is a streak artifact which arises from a high spatial frequency interface between tissues with a great difference in the density.

A) edge gradient
B) retrospective synchronization
C) tube arcing
D) cone beam effect

In which direction are streaks from the edge gradient effect orientated?

A) perpendicular to direction of the sharp density difference
B) radially outward from center
C) parallel away from the direction of the sharp density difference
D) parallel to the direction of the sharp density difference

Which would NOT help differentiate pathology from a partial volume artifact?
(1) rescan, decrease pitch, same slice thickness
(2) inspect adjacent slices
(3) collect additional thinner slices through suspicious region

A) 1,2,3
B) 1,3
C) 1,2
D) 1 only

Which would reduce out-of-field artifacts?

A) increasing scan FOV
B) decreasing scan FOV
C) increase matrix
D) decreasing recon FOV

What causes cone beam artifacts?

A) using filtered back projection on beam thickness over 20mm
B) faulty detector elements
C) beam hardening on MDCT
D) inefficient x-ray tubes on MDCT

Which could result from partial volumizing?
(1) decreased edge sharpness
(2) ghosting of tissue boundaries
(3) inaccurate CT numbers

A) 1,2,3
B) 2,3
C) 1,3
D) 1,2

What results from a faulty detector element on a localizer image?

A) perpendicular lines along the long axis of patient table
B) circle artifacts on one side of the image
C) parallel lines along the long axis of patient table
D) 1 parallel line along the long axis of patient table

What would result if the aperture filter of the x-ray tube removed even more low energy x-ray photons?

A) decreased partial voluming
B) increased beam hardening
C) increased beam hardening
D) decreased beam hardening

What happens with decreased slice thickness?

A) decreased partial voluming, patient dose, and edge gradient artifact
B) decreased partial voluming and edge gradient artifact, but increasing patient dose
C) increased partial voluming, patient dose, and edge gradient artifact
D) decreased partial voluming, but increasing edge gradient and patient dose