Intro to Imaging Pt. 1 (9/6a)

Question 1

Conventional radiograph

Answer 1

x-rays or plain films

image made by x-rays passing through the body onto film, ionizing silver emulsion on the film

Question 2

Attenuation

Answer 2

degree to which the tissue absorbs/scatters x-rays before they hit the recording medium

Question 3

Amount of attenuation depends on

Answer 3

thickness, atomic number, and density of tissue

Question 4

Greater attenuation

Answer 4

Structure is more radiodense

appears whiter

Question 5

Less attenuation

Answer 5

Structure is more radiolucent

appears blacker

Question 6

Radiodense

Answer 6

structure absorbs and scatters x-rays to the largest degree in the body

highest attenuation

EX: bone

Question 7

Radiolucent

Answer 7

x-rays pass right through the structure and aren’t absorbed

lowest attenuation

EX: gas in lungs

Question 8

Radiopaque

Answer 8

not naturally occurring in the body

will be bright white because of high atomic numbers

highest in the radiodensity scale

EX: metal

Question 9

Most radiodense bone

Answer 9

Cortical bone

in relation to inner spongy bone

Question 10

Radiodensity Scale

Answer 10

(least → most radiodense)

1) air - black
2) fat - charcoal
3) water - gray
4) bone - light gray
5) metal - white

Question 11

Contrast

Answer 11

relative shade difference between adjacent structures

Question 12

Density vs Contrast relationship

Answer 12

greater difference in density/thickness → greater contrast

Question 13

Standard A to P

Answer 13

X-rays pass through the tissue next to the film plate, which is located behind the patient in the anterior (A) to posterior (P) direction

Question 14

Exceptions to A→P rule

Answer 14

Chest - done P to A because lungs and heart are more anterior

Hands/Feet - done P to A with palm or sole down on film plate

Question 15

How to hold radiograph for standard A→P

Answer 15

hold it as if the person faced you in anatomical position

Put the R on the right side, if it is an L marker hold it so L is on the left

Question 16

How to hold radiograph for chest

Answer 16

Viewed in anatomical position

Question 17

How to hold radiograph for hand/foot

Answer 17

Viewed as taken

Question 18

Position (radiograph)

Answer 18

Refers to:

1) patient’s general body position (EX: supine, erect)
2) specific body position or which body part is closest to image receptor

Question 19

Projection (radiograph)

Answer 19

describes the path the x-ray through the patient and onto the recording medium

Question 20

How many projections are needed (radiograph)

Answer 20

Need at least 2 projections as close to 90 deg to each other to view a structure in all 3 planes

Question 21

Routine series (radiograph)

Answer 21

Typically done A→P, but each joint has a “routine series” (aka projections) deemed necessary to get comprehensive view

Question 22

ABC’S of Radiographs

Answer 22

A - Alignment
B - Bone density
C- Cartilage
S - Soft tissue

Question 23

Alignment (radiograph)

Answer 23

Size, number, shape and contour

Bone and joint position

Most common cause of malalignment is trauma
(can cause more radiodensity of muscle)

Question 24

Bone density (radiograph)

Answer 24

Cortical bone should be a bright white tube that is more radiodense than the adjacent

Trabeculae (normal stress on the bone) indicate healthy bone

Sclerosis

Osteopenia

Question 25

Sclerosis (radiograph)

Answer 25

increased whiteness that is unusual

due to lack of cartilage

therefore bone on bone/doing all the weight bearing

Question 26

Trabeculae (radiograph)

Answer 26

fine lines at the end of the cortical bone

Question 27

Osteopenia (radiograph)

Answer 27

bone is less dense than it is supposed to be

Must be diagnosed by physician

Question 28

Cartilage (radiograph)

Answer 28

Look for space between the joint to be radiolucent, equal and big

Bone on bone is cartilage depletion

Question 29

Soft tissue (radiograph)

Answer 29

Degree of contrast is abnormal during trauma

Fat pad sign - posteriorly on the x ray of an elbow means a fracture in the joint