SUBJECT FACTORS

Question 1

SUBJECT FACTORS

Answer 1

-SUBJECT CONTRAST
-PATIENT THICKNESS
-TISSUE MASS DENSITY
-EFFECTIVE ATOMIC NUMBER
-OBJECT SHAPE
-KILOVOLTAGE PEAK

Question 2

The contrast of a radiograph viewed on an illuminator is
called

Answer 2

radiographic contrast

Question 3

is a function of image receptor
contrast and subject contrast.

Answer 3

Radiographic contrast

Question 4

The degree of subject contrast is directly
proportional to the relative number of x-rays leaving those sections of the body.

Answer 4

PATIENT THICKNESS

Question 5

is an important
factor that affects subject contrast.

Answer 5

Tissue mass density

Question 6

The effect of mass density on
subject contras

Answer 6

TISSUE MASS DENSITY

Question 7

adjacent tissues is very much different,
subject contrast is very high.

Answer 7

EFFECTIVE ATOMIC NUMBER

Question 8

Subject contrast can be enhanced
greatly by the use of

Answer 8

contrast media

Question 9

Contrast media are effective
because they accentuate subject
contrast through enhanced

Answer 9

photoelectric
absorption

Question 10

The shape of the anatomical structure
under investigation influences its
radiographic quality, not only through its
geometry but also through its
contribution to subject contrast.

Answer 10

Object shape

Question 11

Structure that has a form that coincides
with the x-ray beam has maximum
subject contrast

Answer 11

Object shape

Question 12

This characteristic of the subject that
affects subject contrast is sometimes
called

Answer 12

absorption blur

Question 13

It reduces the ____ and ____of any anatomical
structure, but it is most troublesome
during interventional procedures in
which vessels with small diameters are
examined.

Answer 13

spatial resolution and the
contrast resolution

Question 14

The absolute magnitude of subject
contrast, however, is greatly controlled
by

Answer 14

the kVp of operation

Question 15

is the most important influence on
subject contrast.

Answer 15

kVp

Question 16

High kVp , Low Subject contrast

Answer 16

Long gray scale

Question 17

Low kVp , High Subject contrast

Answer 17

Short gray scale

Question 18

As the kVp is lowered for any radiographic examination, the x-ray
beam becomes less penetrating, requiring a higher mAs to
produce an acceptable range of ODs. The result is

Answer 18

higher patient
dose.

Question 19

Movement of the patient or the x-ray tube during exposure results
in blurring of the radiographic image.

Answer 19

MOTION BLUR

Question 20

The radiographer can reduce motion blur by carefully instructing the
patient,

Answer 20

Take a deep breath and hold it. Don’t move.

Question 21

Patient motion of two types may occur.

Answer 21

1.Voluntary motion
2.Involuntary motion

Question 22

of the limbs and muscles is controlled by
immobilization.

Answer 22

Voluntary motion

Question 23

of the heart and lungs is controlled by short
exposure time.

Answer 23

Involuntary motion

Question 24

the heart and lungs is controlled by short
exposure time.

Answer 24

Involuntary motion

Question 25

PROCEDURES FOR REDUCING MOTION BLUR

Answer 25

-Use the shortest possible exposure time.
-Restrict patient motion by providing instruction or using a restraining device.
-Use a large SID
-Use a small OID

Question 26

Proper patient positioning requires that the anatomical structure
under investigation be placed as close to the image receptor as is
practical and that the axis of this structure should lie in a plane that
is parallel to the plane of the image receptor.

Answer 26

PATIENT POSITIONING

Question 27

of screen-film image receptor is used throughout a
radiology department for a given type of examination.

Answer 27

standard type

Question 28

Most other radiographs use

Answer 28

double-emulsion film with screens.

Question 29

Most other radiographs use

Answer 29

double-emulsion film with screens.