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

PT605 > Intro to Imaging Pt. 1 (9/6a) > Flashcards

Flashcards in Intro to Imaging Pt. 1 (9/6a) Deck (29)
Loading flashcards...
1

Conventional radiograph

x-rays or plain films

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

2

Attenuation

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

3

Amount of attenuation depends on

thickness, atomic number, and density of tissue

4

Greater attenuation

Structure is more radiodense

appears whiter

5

Less attenuation

Structure is more radiolucent

appears blacker

6

Radiodense

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

highest attenuation

EX: bone

7

Radiolucent

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

lowest attenuation

EX: gas in lungs

8

Radiopaque

not naturally occurring in the body

will be bright white because of high atomic numbers

highest in the radiodensity scale

EX: metal

9

Most radiodense bone

Cortical bone

(in relation to inner spongy bone)

10

Radiodensity Scale

(least → most radiodense)

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

11

Contrast

relative shade difference between adjacent structures

12

Density vs Contrast relationship

greater difference in density/thickness → greater contrast

13

Standard A to P

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

14

Exceptions to A→P rule

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

15

How to hold radiograph for standard A→P

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

16

How to hold radiograph for chest

Viewed in anatomical position

17

How to hold radiograph for hand/foot

Viewed as taken

18

Position (radiograph)

Refers to:

1) patient’s general body position (EX: supine, erect)

2) specific body position or which body part is closest to image receptor

19

Projection (radiograph)

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

20

How many projections are needed (radiograph)

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

21

Routine series (radiograph)

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

22

ABC'S of Radiographs

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

23

Alignment (radiograph)

Size, number, shape and contour

Bone and joint position

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

24

Bone density (radiograph)

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

25

Sclerosis (radiograph)

increased whiteness that is unusual

due to lack of cartilage

therefore bone on bone/doing all the weight bearing

26

Trabeculae (radiograph)

fine lines at the end of the cortical bone

27

Osteopenia (radiograph)

bone is less dense than it is supposed to be

Must be diagnosed by physician

28

Cartilage (radiograph)

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

Bone on bone is cartilage depletion

29

Soft tissue (radiograph)

Degree of contrast is abnormal during trauma

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