RadReview September Image Production/Quality Management

In Figure 5-8, which of the illustrated x-ray tubes permit(s) an exposure of 400 mA, 0.1 s, and 80 kVp? 1.Tube A 2.Tube B 3.Tube C

1 and 2 only

For a given FOV, as the matrix size increases 1. Pixel size decreases 2. Image quality decreases 3. Spatial resolution increases

1 and 3 only

Which of the following mathematical formulas is used to calculate the magnification factor? MF = SOD ÷ SID MF = OID ÷ SOD MF = OID ÷ SID MF = SID ÷ SOD

MF = SID ÷ SOD

What term describes the shortest exposure time that a particular AEC system can produce? Backup time Density controls Minimum response time mAs readout

Minimum response time

How should technical factors be adjusted manually, from normal adult technique, in pediatric radiography to minimize possible motion? Shorter exposure time and lower mA should be used. Longer exposure time and lower mA should be used. Extended exposure time and higher mA should be used.

Shorter exposure time and lower mA should be used.

Focal spot size impacts which image quality feature? Receptor exposure Spatial resolution Image contrast Image brightness

Spatial resolution

Select the one incorrect statement below: TFT size in digital systems impacts spatial resolution. The DAC is the device that converts PSL to an electronic signal for display. Incomplete erasure of the PSP can cause "ghost" images. The grid frequency recommended for CR is 70 line/centimeter.

The DAC is the device that converts PSL to an electronic signal for display.

What is the effect of TFT DEL size in cassetteless digital imaging? The smaller the DEL size, the better the spatial resolution. The smaller the DEL size, the worse the spatial resolution. As DEL size decreases, brightness increases As DEL size decreases, brightness decreases

The smaller the DEL size, the better the spatial resolution.

When using an AEC system, what will happen once the predetermined amount of radiation is transmitted? The x-ray exposure will continue for approximately .05 seconds The x-ray exposure will terminate The image receptor will be overexposed The image receptor will be underexposed

The x-ray exposure will terminate

Which of the following factor(s) is/are most likely to have an impact on image distortion? I. OID II. beam restriction III. protective filtration IV. grids

1 only

Advantages of flat-panel digital fluoroscopy system include: 1. better contrast resolution 2. uniformly distortion-free images 3. high DQE

1, 2, and 3

How much kV reduction can be expected using three-phase equipment compared to single-phase equipment? 10 kV 11 kV 15 kV 20 kV

10 kV

When using an AEC system, the backup time should be set at 100% of the expected exposure time 125% of the expected exposure time 150% of the expected exposure time 175% of the expected exposure time

150% of the expected exposure time

If FOV increases, pixel size 1. Decreases 2. Increases 3. Stays the same 4. Gets smaller

2 only

With AEC, the area of interest must be placed directly over the selected detectors in order to avoid which two of the following? (select the two that apply) A. Overexposure B. Underexposure C. Decrease in contrast D. Increase in contrast

A and B

Which device has greater sensitivity to light and provides a higher SNR (signal-to-noise ratio) and improved contrast resolution? A TV camera A charge coupled device A TV camera and a charge coupled device have equal sensitivity to light, provide equal signal-to-noise ratio, and equal contrast resolution None of the above

A charge coupled device

Adjacent to the output phosphor of the digital fluoroscopy image intensifier tube is A TV camera and CCD A fiber optic bundle and CCD A fiber optic bundle and TV camera A TV camera only

A fiber optic bundle and CCD

The abbreviation of the fluoroscopic feature that changes kV and/or mAs according to part thickness is ADC ABC PSP DAP

ABC

Which of the following is NOT considered a positive contrast agent? Barium Iodine Air Metal

Air

Compared with the image on the input phosphor, the image on the output phosphor is minified. brighter. inverted. All of the above

All of the above

Which of the following are types of beam restrictors? I. Cones (cylinder and flare) II. Collimators III. Aperture diaphragms

All of the above

What is the name of the computerized system in which the radiographer has a selection of exams available on the console from which to choose? Anatomical radiography Programmed radiography (anatomical) Anatomically programmed radiography None of the above

Anatomically programmed radiography

Which of the following statements regarding matrix size is true? As matrix size increases, pixel size increases. As matrix size decreases, sharpness increases As matrix size increases, pixel size decreases. As matrix size decreases, pixel size remains the same.

As matrix size increases, pixel size decreases.

Which of the following post-processing terms serve to suppress image noise? (select the two that apply) A. High-pass filtering B. Low-pass filtering C. Smoothing D. Sharpening

B and C

Select the one incorrect statement below: A. A primary display workstation is one that is used for image interpretation. B. The higher/greater the bit depth in digital imaging, the lesser the number of gray shades. C. Exposure field recognition errors usually occur from scattered radiation outside the VOI area, often as a result of improper alignment of part, x-ray beam, and IP. D. Direct digital systems have a fixed spatial resolution that is determined by TFT detector element (DEL) size.

B. The higher/greater the bit depth in digital imaging, the lesser the number of gray shades.

A wider (increased) window width (select the two that apply) A. decreases the range of densities B. increases the image contrast C. increases the range of densities D. decreases the image contrast

C and D

How do changes in pixel density and pixel pitch impact spatial resolution? A. Increased pixel density increases spatial resolution; decreased pixel pitch decreases spatial resolution. B. Increased pixel density decreases spatial resolution; decreased pixel pitch increases spatial resolution. C. Increased pixel density decreases spatial resolution; increased pixel pitch increases spatial resolution. D. Increased pixel density increases spatial resolution; decreased pixel pitch increases spatial resolution.

D. Increased pixel density increases spatial resolution; decreased pixel pitch increases spatial resolution.

Select the one incorrect statement below: A. If there are too few x-ray photons reaching the digital image receptor the resultant image will appear noisy/quantum mottle/graininess. B. Exposure indicators (EI), expressed as S number, EI value, or lgM number depending on equipment type, indicate the acceptable range of exposure in digital imaging. C. Precise/close collimation should be used with digital systems because excessive scatter causes histogram analysis errors. D. Quantum mottle often occurs in CR imaging when using an IP that has not been used or erased for 48 hours or more.

D. Quantum mottle often occurs in CR imaging when using an IP that has not been used or erased for 48 hours or more.

Select the one incorrect statement from those listed below: A. Exposure timer accuracy (greater than 10 ms) should be within 10% of the selected exposure time. B. When evaluating kVp calibration, the measured kVp should be within +/- 5kV of the selected kVp. C. The SSD in diagnostic mobile radiography must not be less than 30 centimeters. D. When evaluating collimator accuracy, the illuminated light field must coincide with the actual x-ray field to within 5% of the SID.

D. When evaluating collimator accuracy, the illuminated light field must coincide with the actual x-ray field to within 5% of the SID.

What term describes the numeric value representing the IR exposure? Electronic noise Spatial resolution Deviation index Fill factor

Deviation index

What term is used to describe the numeric value representative of the exposure the IR receives in digital radiography? Exposure indicator Window level Window width Pixel value

Exposure indicator

The comprehensive integrated system that is designed to manage medical, administrative, financial, and legal aspects of hospitals is known as? Radiology information system (RIS) Hospital information system (HIS) Picture archiving communication system (PACS) Digital imaging and communications in medicine (DICOM)

Hospital information system (HIS)

From the following list, select the factor(s) that are most likely to have an impact on image contrast: I. motion II. beam restriction III. protective filtration IV. grids

II and III only

Select the condition(s) that are likely to require a decrease in exposure: I. congestive heart failure II. sclerosis III. Pneumothorax IV. Osteoporosis V. cirrhosis

III and IV only

For the same FOV, arrange the following radiography matrix sizes in order of increasing spatial resolution I. 1500 x 1500 II. 2500 x 2500 III. 750 x 750

III, I, II

In what two ways can we reduce the production of scattered radiation? Use of beam restriction and appropriate kV level Use of beam restriction and appropriate mA level Use of grids and appropriate kV level Use of grids and appropriate mA level

Use of beam restriction and appropriate kV level

What type of technique chart is based on the concept that kVp should be increased as anatomic part size increases? Variable kVp-fixed mAs Variable mAs-fixed kVp Automatic exposure control Anatomically programmed radiography

Variable kVp-fixed mAs

The photoconductor generally used with a TFT array in direct capture digital imaging is aluminum oxide. amorphous selenium. zinc cadmium sulfide. amorphous silicon.

amorphous selenium.

PSPs must be processed and read soon after exposure because signal loss (image fading) becomes apparent after approximately 90 minutes. eight hours. one week. three months.

eight hours.

An increase in mA is associated with decreased SNR. increased SNR. decreased photon intensity decreased photon wavelength

increased SNR.

Manipulation of grey level values is associated with lookup table and window width window level and lookup table. window level and edge enhancement. window width and edge enhancement

lookup table and window width

A wide window width will display an image having high contrast. low contrast. high brightness. low brightness.

low contrast.

Which of the following is the factor of choice to adjust/correct image receptor exposure? kVp mAs SID Filtration

mAs

Which primary exposure technique factor is directly proportionate to the image receptor exposure? kVp mAs SID Tube filtration

mAs

Which of the following is NOT true of mAs in digital systems? mAs no longer controls density mAs determines patient dose mAs is selected to provide sufficient quanta/intensity mAs no longer controls the quantity of radiation that forms the image

mAs no longer controls the quantity of radiation that forms the image

A step-up transformer has more primary coils than secondary coils. more secondary coils than primary coils. the same number of coils as the filament transformer. the same number of secondary and primary coils.

more secondary coils than primary coils.

The greatest enemy of record image detail is: large focal spot. part angle. tube angle. motion.

motion.

The action of materials that absorb x-ray energy and emit visible light in response is termed magnification scintillation emission detection

scintillation

The magnitude of the signal differences in the remnant beam that results from the differing absorption properties of the part describes quantum noise. subject contrast. image contrast. spatial resolution.

subject contrast.

Requirements for a tilting x-ray table to be used for fluoroscopy are tilting 30° to the foot side and 30° to the head side. tilting 90° to the foot side and 90° to the head side. tilting 90° to the foot side and 30° to the head side. tilting 30° to the foot side and 90° to the head side.

tilting 90° to the foot side and 30° to the head side.