Chapter 13: Radiographic Image Characteristics

Which combination of variables will results in a radiograph with the lowest receptor exposure? (letter) a. 100 kVp, 50 mAs, 14x17 receptor b. 85 kVp, 100 mAs, 10x12 receptor c. 75 kVp. 50 mAs, 14x17 receptor d. 85 kVp, 25 mAs, 10x12 receptor

D

The greater the OID, the ________ the magnification will be. a. greater b. less

greater

The greater the number of photons (intensity) that reach the image receptor, the: a. greater the penumbra b. greater the contrast c. greater the density d. lower the contrast

greater the density

Choose the term that is synonymous with short gray scale. a. high contrast b. low contrast c. many shades of gray

high contrast

An image with high spatial resolution would also be described as having: a. high blur b. high mottle c. high sharpness d. high distortion

high sharpness

An image is blurred. To increase sharpness of detail, the technologist could: a. increase exposure time b. decrease kVp and mAs c. use a double screen cassette d. increase SID

increase SID

A decubitus radiograph is acquired using 72 kVp, a 12:1 grid, 72 inch SID, 600 mA, and using AEC. Which of these variable modifications will decrease the exposure time? a. decrease kVp b. increase the grid ratio c. increase mA d. increase SID

increase mA

If only mAs increases, then IR intensity and patient absorbed dose ______________ a. increase, decrease b. decrease, increase c. increase, increase d. decrease, decrease

increase, increase

When a larger focal spot size is used, how will it affect the focal spot blur? a. increased b. decreased c. no change

increased

Which of these changes will decrease blur in a radiographic image? a. increased SID b. decrease SOD c. decrease kVp d. increased FSS

increased SID

Long-scale contrast radiographs are obtained using: a. decreased mAs b. increased mAs c. decreased kVp d. increased kVp

increased kVp

Long-scale contrast radiographs are obtained using: a. increased mAs b. decreased mAs c. increased kVp d. decreased kVp

increased kVp

Which of these factors are expected to decrease spatial resolution in the radiographic image? a. increased motion b. increased kVp c. increased mAs d. increased SID

increased motion

Increasing the SID results in decreased beam divergence and: a. decreased spatial resolution b. increased spatial resolution c. no change in spatial resolution

increased spatial resolution

The area of blue around the image is known as the: a. photoelectric effect b. penumbra c. contrast d. magnification factor

penumbra

A form of involuntary motion

peristalsis

Calculate the focal spot blur for a radiograph acquired using a 40 inch SID, 2 inch OID, and a 0.1 inch FSS. a. 0.01 inch b. 0.0053 inch c. 1.9 inch d. 0.019 inch

0.0053 inch

If a radiograph is produced using a mA of 400 and 0.05 seconds, how should the exposure time be changed if the mA is decreased to 200? a. 0.025 seconds b. 0.015 seconds c. 0.20 seconds d. 0.10 seconds

0.10 seconds

The values below were recorded on four different x-ray imaging systems. Which of these values represents the highest level of geometric sharpness? a. 20 lp/mm b. 18 lp/mm c. 16 lp/mm d. 14 lp/mm

20 lp/mm

An image of the sacrum measures 25 cm long on the film. The radiograph was taken under the following conditions: SID = 100 cm and OID = 75 cm. Calculate and select the correct magnification factor. a. 1.33 b. 0.9 c. 2 d. 4

4

If all other exposure variables remain constant, which of these OIDs will produce a radiograph with the least amount of image blur? a. 72 inches b. 40 inches c. 12 inches d. 4 inches

4 inches

Density differences on an image

Contrast

Which of the following would have the most effect on magnification of the image on a finished radiograph? a. OID b. motion c. focal spot size d. system speed

OID

The magnification factor will be 2 when the: (letter) a. SID = SOD b. SID = OID c. SOD = OID d. OID > SOD e. OID < SOD

D

Degree of blackness on an image

Density

Misrepresentation of an object on an image, either in its size of in its shape

Distortion

Size distortion or magnification will be affected by all of the following except: a. SID b. SOD c. OID d. FSS

FSS

Size distortion will be affected by all except the following? a. SID b. SOD c. OID d. FSS

FSS

Type of distortion that makes an object appear larger than its actual size

Magnification

___________ is the degree of blackening on the film. a. OD b. radiographic density c. subject contrast d. tissue thickness

OD

Recorded detail can be enhanced by decreasing the: a. OID b. SID c. mAs d. kV

OID

The primary controlling factor for magnification is: a. kVp b. mAs c. focal spot size d. OID

OID

What is the relationship between matrix size and radiographic spatial resolution? a. as matrix size increases, spatial resolution decreases b. matrix size has no effect on spatial resolution c. as matrix size increases, spatial resolution increases

as matrix size increases, spatial resolution increases

A radiographic image with a low level of penumbra could also be described as having: (select all that apply) a. high spatial resolution b. high blur c. high sharpness

a and c

Changing the kVp from 60 to 70 kVp and decreasing the mAs by one-half results in: a. a shorter scale of contrast b. increased optical density c. a longer scale of contrast d. decreased optical density

a longer scale of contrast

The body part under study should be placed as _________ as possible to the IR: a. close b. far away

close

Using as large a SID as possible, will ____________ size distortion. a. increase b. decrease

decrease

A UGI image is blurred. Based on the type of exam being conducted, to increase sharpness of detail the technologist could: a. decrease the exposure time b. use a single screen cassette c. decrease kVp and mAs d. decrease SID

decrease exposure time

In order to increase contrast, the technologist should: a. increased mAs b. decrease kVp c. increase SID d. decreased grid ratio

decrease kVp

An increase in the SID will: a. increase penumbra b. increase blur c. decrease penumbra d. no change in penumbra

decrease penumbra

Scatter and radiation fog have what effect on radiographic quality? a. reduce penumbra of the image b. create penumbra in the image c. decrease the contrast of the image d. increase the contrast of the image

decrease the contrast of the image

As matrix size increases, pixel size: a. increases b. decreases c. stays the same

decreases

Occurs when the object is parallel to the IR, but the x-ray tube is angled: a. elongation b. foreshortening

elongation

SOD = SID + OID. T/F?

false

In a direct capture radiography system, a decreased detector element (DEL) size results in: a. decreased spatial resolution b. increased spatial resolution c. no change

increased spatial resolution

Digital receptor systems with a large DEL pitch will have: a. low spatial resolution b. high spatial resolution c. pitch does not affect spatial resolution

low spatial resolution

The space between detector elements is called the: a. matrix size b. bit depth c. pitch d. exposure latitude

pitch

The space between pixels in a digital image is called the: a. pitch b. matrix size c. bit depth d. exposure latitude

pitch

To calculate the magnification factor: a. divide the SID by the OID b. divide the object size by the image size c. divide the SID by the SOD d. divide the OID by the SID

divide the SID by the SOD

The magnification equation is "Image size/object size = SOD/SID". T/F?

false

The only factor that alters image sharpness is: a. mAs b. kVp c. anode material d. focal spot size

focal spot size

Which of the following factors have no effect on contrast? a. kVp b. focal spot size c. grid ratio d. beam restriction of collimation

focal spot size

Occurs when the object is at an angle to the IR, but the central ray is perpendicular to the IR: elong/fore?

foreshortening

Radiographic contrast is defined as: a. the difference in densities between adjacent areas b. the difference in attenuation between adjacent areas c. the difference in scattering between adjacent areas d. the difference in bremsstrahlung between adjacent areas

the difference in densities between adjacent areas

In a radiographic image, focal spot blur is decreased by increasing: a. the size of the x-ray field b. the size of the focal spot in the x-ray tube c. the distance from the focal spot to the patient d. the patient motion

the distance from the focal spot to the patient

Spatial resolution in digital radiography is defined as: a. the structural sharpness recorded in the radiograph b. the total number of brightness level in the radiograph c. the amount of geometric distortion displayed in the radiograph d. the total number of photons absorbed by the image receptor

the structural sharpness recorded in the radiograph

Image gray-scale is defined as: a. the total brightness levels that are visible in a radiographic image b. the total amount of blur recorded in a radiographic image c. the total brightness levels that an imaging monitor is capable is displaying

the total brightness levels that are visible in a radiographic image

Image contrast is defined as: a. the visible difference in recorded detail between two different radiographs b. the visible difference in brightness between two areas in an image c. the visible difference in visible detail between two different radiographs

the visible difference in brightness between two areas in an image

Which of these anatomical parts can be an indicator of the spatial resolution recorded in a radiographic image? a. bowel gas b. trabecular bone c. muscular structures d. fat tissues

trabecular bone

For the least amount of shape distortion, the object should be parallel to the IR, and the central ray should be perpendicular to both the object and the IR. T/F?

true

The magnification factor is = SID/SOD. T/F?

true

Which of these variables affect the spatial resolution recorded in the radiographic image? a. SID b. kVp c. mAs

SID

Measured using lp/mm

Sharpness

An image with high-contrast would also have these characteristics: (select all that apply) a. long gray scale b. short gray scale c. few shades of gray d. many shades of gray

b and c

If only kVp increases, then contrast ________ and patient absorbed dose ____________. a. increase, decrease b. decrease, increase c. increase, increase d. decrease, decrease

decrease, decrease

If the kV is increased, the resulting image should exhibit ______ contrast. a. increased (short scale) b. increased (long scale) c. decreased (short scale) d. decreased (long scale)

decreased (long scale)

Consider this scenario: During a cross-table lateral c-spine you decrease the SID from 72 inches to 60 inches. How will this modification affect the detail recorded in the image? a. no change in recorded detail b. increased recorded detail c. decreased recorded detail

decreased recorded detail

Consider this scenario: During a routine x-ray of an extremity, you change the exposure settings from the small filament to the large filament. How will this change affect the spatial resolution? a. decreased spatial resolution b. increased spatial resolution c. no change in spatial resolution

decreased spatial resolution

Increasing FSS has what effect on spatial resolution? a. decreased spatial resolution b. increased spatial resolution c. no change in spatial resolution

decreased spatial resolution

Increasing the OID from 1 inch to 2 inches will result in: a. decreased spatial resolution b. increased spatial resolution c. no change in spatial resolution

decreased spatial resolution

Which of the following has/have no effect on sharpness of detail? a. penumbra b. motion c. density d. lp/mm

density

Which of the following has/have no relation to sharpness or recorded detail? a. penumbra b. motion c. density d. lp/mm

density

Density and mAs have what relationship? a. direct b. indirect c. none

direct

A variation from the true shape of the part being radiographed is defined as: a. misrepresentation b. facsimile c. magnification d. distortion

distortion

If the central ray is not placed so that it is directed through the center of the anatomy, the radiographic quality most affected will be: a. density b. contrast c. detail d. distortion

distortion

A satisfactory x-ray of the wrist is produced using a technique of 300 mA, 15 milliseconds, 50 kVp, and a SID of 40 inches. How should the mA be changed if the exposure time is decreased to 10 milliseconds? a. 200 mA b. 450 mA c. 255 mA d. 185 mA

450 mA

If all other exposure variables remain constant, which of these OIDs will produce a radiograph with the highest level of spatial resolution? a. 12 inches b. 5 inches c. 72 inches d. 60 inches

5 inches

Which type of image represents high contrast? (letter) a. mostly black and white, few shades of gray b. few blacks and whites, lots of shades of gray

A

Calculate the magnification factor for a radiograph made with a 40 inch SID and a 4 inch OID. a. 10 b. 0.9 c. 0.055 d. 1.11

1.11

A radiograph of the sella turcica was performed using an SID of 40 in. The sella turcica has a 10 in OID. What is the magnification factor of the sella turcica? a. 0.25 b. 0.75 c. 1.33 d. 4.0

1.33

What is the magnification factor with a 40-inch SID and a 30-inch SOD? a. 0.75 b. 1.33 c. 1.2 d. 0.80

1.33

An x-ray of the chest uses a 72 inch SID. If the image of the heart measures 12 cm and the actual heart measures 7 cm, what is the magnification factor? a. 5.0 b. 9.0 c. 1.7 d. 0.58

1.7

Which of the following combination of factors will provide the greatest detail? (letter) a. short SID, short OID, small FSS b. long SID, short OID, small FSS c. long SID, long OID, large FSS d. short SID, long OID, large FSS

B

Which combination of variables will results in a radiograph with the highest contrast? (letter) a. 101 kVp, 54 mAs, 1 mm filament b. 80 kVp, 100 mAs, 2 mm filament c. 74 kVp, 60 mAs, 1 mm filament d. 120 kVp, 54 mAs, 2 mm filament

C

Which of the following would improve radiographic quality if patient motion is a problem? (letter) a. 0.6 mm focal spot, 100 mA, 0.25s b. 0.6 mm focal spot, 200 mA, 0.125s c. 0.6 mm focal spot, 300 mA, 0.083s d. 1.2 mm focal spot, 500 mA, 0.050s

C

Tube angle toward the head

Cephalad

Type of shape distortion that makes an object appear smaller than its actual size

Foreshortening

Aluminum step wedge

Penetrometer

Blur, occurs around the edge of an image

Penumbra

Radiographic contrast depends on: a. tissue thickness b. tissue density c. kVp d. all of the above

all of the above

Subject contrast depends on: a. tissue thickness b. tissue density c. tissue atomic number d. all of the above

all of the above

Which of these changes will improve the spatial resolution recorded in the radiographic image? a. decrease FSS b. decrease OID c. increase SID d. all of the above

all of the above

Which of these equipment factors can influence spatial resolution in radiography? a. detector element (DEL) size b. detector element (DEL) pitch c. matrix size d. pixel size e. all of the above

all of the above

The primary factor that controls image contrast is the: a. kVp b. mAs c. SID d. focal spot size

kVp

A radiograph has been determined to have high contrast. This means that the density differences between the structures are: a. relatively small b. exactly equal c. large d. greater than 0.5 on a densitometer reading

large

The degree of spatial resolution is determined by: a. line focus principle b. line pairs per millimeter c. spinning top test d. wire mesh test

line pairs per millimeter

The spatial resolution of a radiographic system is measured with units of: a. line pairs per millimeter b. milligray c. milligray-centimeters squared d. bits

line pairs per millimeter

Low contrast is defined by: a. short gray scale b. long gray scale c. few shades of gray

long gray scale

Which contrast is produced with a higher kV: a. short scale b. long sclae

long scale

Long gray scale is defined as: a. high contrast b. low contrast c. few shades of gray

low contrast

The primary factor that controls density is: a. kVp b. grids c. mAs d. SID

mAs

A variation from the true size and enlargement of the part being radiographed is defined as: a. contrast resolution b. facsimile c. magnification d. shape distortion

magnification

A high-contrast film has a _____________ latitude. a. wide b. narrow

narrow

Do either the mAs or SID used affect the radiographic contrast produced? a. yes b. no

no

Scatter radiation does not affect: a. visibility of spatial resolution b. image contrast c. occupational dose d. recorded spatial resolution

recorded spatial resolution

Radiographic contrast consists of a combination of: a. subject contrast and scattering b. subject contrast and film contrast c. film contrast and grid contrast d. density and mAs

subject contrast and film contrast