Mobile Imaging PPT Flashcards Preview

Hannah RAD III > Mobile Imaging PPT > Flashcards

Flashcards in Mobile Imaging PPT Deck (53):
1

What locations are mobile x‐ray
machines commonly used in?

Nursing Home
ED
PACU
Post surgery
ICU
Neonatal Units

2

Historical overview

• Military for treating battlefield injuries during
WW1
• Small portable units carried (“portable”) by
soldiers and set up in the field

3

Who invented the 1st portable machine?
(the product infield of refrigerator)

Frederick Jones

4

Who got a Noble Prize-winning physicist & put money to portable machines into WW I ambulances?

Marie Curie

5

***What are the ranges for kVp on a mobile x-ray machine?

40 to 130 kVp

6

***What are the ranges for mAs on a mobile x-ray machine?

0.04 to 320 mAs

7

What is the total unit of power for a mobile x-ray machine?

Between 15 and 25 kW

8

What is an MOBILE X-RAY MACHINE?

•Preset anatomic programming with exposure
techniques based on selected exam
•Direct digital capability
•Flat panel detector

9

What are the two classifications of mobile x-ray machines?

Battery operated units
Capacitor discharge units

10

What is Battery operated units?

•2 sets of batteries
• 10 to 16 12 volt batteries connected in a series
• One controls x‐ray power output
• Provides power for self‐propelling driving ability

11

Average walking speed
Battery operated units

2.5 to 3 mph

12

Maximum incline of Battery operated units is

7 degrees

13

***Battery operated units when fully charged

10 to 15 exposures
10 miles on level ground
8 hours charging time

14

Driving mechanism of Battery operated units

• Forward/reverse
•Deadman brake
•Machine instantly stops when handle is released

15

***Advantages of Battery operated units

• Cordless
• Constant kVp and mAs

16

What is CAPACITOR-DISCHARGE
UNITS?

•Do not operate on batteries
•Capacitor stores electrical energy & charges
briefly before each exposure
•Capacitor builds up a charge when the exposure
button is pushed; when the pre‐selected charge
is reached, capacitor sends charge to x‐ray tube

17

***What are the advantages of the capacitor-discharge unit?

• Smaller size
• Easy to move
• Lighter in weight

18

What are the disadvantage of the capacitor-discharge unit?

• kVp drops constantly during exposure
• kVp may start @ 100 and drop to 80 kVp by end of
exposure

19

***What are the three important technical factors for mobile imaging?

Grid
Anode heel effect
SID

20

***Grid must be

Level
Centered to CR
Correctly used @ recommended focal distance

21

The incorrect use of a grid can result in loss of density across all or part of an image. Grid cut-off can result from 4 factors:

1. off-center grid
2. off-level grid
3. off-focus grid
4. upside-down grid

22

***If a longitudinal grid tilts transversely such as when placing under a patient on a mattress, the CR forms an angle across the long axis of the grid resulting in:

"Grid cutoff" results or
A lost of image density

23

If a longitudinal grid Tilts longitudinally, CR is angled but through long axis resulting in

Image is distorted
NO grid cutoff

24

***Grid cutoff results if

CR is directed transversely off from midline of
grid by more than 1 to 1 ½”

25

The more CR is off centered

The greater the grid cutoff.

26

***What is Grid cutoff?

Decreases density on image

27

***What is the ratio range for most focus type grids?

6:1 or 8:1

28

What is the focal range for most focus type grids?

36 to 44” focal range

29

Recommended focal range

• Varies with grid ratio
•Projections taken@ distances greater or less than
recommended distance produces cutoff
• Reduced image density @ lateral margins

30

***What is the grid ratio for portable grid?

6:1 or 8:1

31

What is the grid ratio for bucky grid?

12:1

32

***What is the concept of the anode heel effect?

The intensity of radiation from the cathode end is greater than at the anode end.

33

***The heel effect causes

a decrease in image density @ anode end due to the greater absorption of x-rays.

34

A thicker body part @ ................end
A thinner part @ ............. end.

Cathode
Anode

35

***The heel effect More defined as

• Short SID
• Large field size
• Small anode angle

36

***Mobile radiography produces some of the ................. occupational radiation exposures for radiographers.

Highest

37

***Recommended minimal distance from mobile unit when making exposure is

6 feet
or length of the cord.

38

***The single most effective means of radiation protection is

Distance

39

***According to the Federal Safety Regulation, SSD or source-to-skin distance cannot be less than

12 inches

40

Maintained @ ................... for most mobile exams

40 inches

41

Longer SIDs require .................................... to
compensate for additional distance

increased mAs

42

OTHER CONSIDERATIONS for mobile are

•Technique chart
•Calipers
•Radiation safety

43

***Stand @ a .................... to primary beam – least
amount of scatter radiation

right angle

44

CHEST – AP PROJECTION


• Internally rotate arms TO move Scapular away
• Ensure no rotation of upper torso
• Midsagittal plane centered to IR
• Top of IR 2” above relaxed shoulders
•CR perpendicular to IR and 3” below jugular
notch @ level of T7

45

AP or PA CHEST PROJECTION (LATERAL DECUBITUS)

• Lateral recumbent
• Place support under patient to elevate 2‐3”
• Coronal plane is vertical
• IR is placed 2” above shoulders
•CR is horizontal & perpendicular entering 3” below jugular notch

46

AP PROJECTION - ABDOMEN

• Position IR to include pubic symphysis to upper abdomen region
•Center MSP to midline of IR
•Center IR to level of iliac crest
•CR perpendicular along MSP @ level of iliac crest or 10th rib laterally

47

***AP or PA PROJECTION – Abdomen Left
Lateral Decubitus Position

• True Left lateral recumbent position with coronal plane vertical
• IR is centered 2” above iliac crest to include
diaphragm
• Before exposure, patient has been in lateral
recumbent position for @ least 5 minutes
• Air to rise/Fluid to settle
•CR horizontal & perpendicular to center of
IR along MSP

48

AP PROJECTION - PELVIS

• 14 x 17 crosswise
• Position IR under pelvis with center midway
between ASIS & pubicsymphysis (2” inferior to
ASIS & 2” superior to pubic symphysis)
•Center MSP to midline of IR
•Rotate patient’s legs medially 15 degrees
•Respiration: Suspend
•CR perpendicular to MSP entering 2” abovepubic symphysis & 2”below ASIS

49

AP PROJECTION – FEMUR (Distal)

• 14 x 17 lengthwise
• Place distal edge of IR low enough to include
fx site, pathologicregion & knee joint
• Elevate IR if necessary to ensure proper alignment with tube – IR parallel to femoral condyles
•Respiration: Suspend
•CR perpendicular to long axis of femur ¢ered to grid
• Structure: distal 2/3 of femur including knee jt

50

AP PROJECTION – FEMUR
(Proximal)

• 14 x 17 lengthwise
• Place under proximal femur & hip
• Top of IR @ ASIS to include hip jt
•CR is directed to center of IR and long axis of femur

51

LATERAL PROJECTION - FEMUR

• 14 x 17 lengthwise
• Include distal knee joint
• Elevate unaffected leg until femur is almost vertical
•CR perpendicular to long axis of femur entering @
midpoint
•Demonstrates distal 2/3 of femur
• Digital
• Measure through thickest part of femur to select appropriate kVp
• Position cathode over proximal femur to improve CR image

52

LATERAL – C-SPINE (Right or left
dorsal decubitus position)

• 10 x 12 lengthwise
• Top of IR 1” above EAM to center IR @ C4
( upper thyroid cartilage)
• Raise chin slightly (contraindicated – fx)
• Relax shoulders
•Respiration: Full expiration
• Depresses shoulders
• SID of 60 to 72”
•CR horizontal and perpendicular @ level of C4
• Ensure proper alignment of CR & IR to prevent grid cutoff
•Must include C7

53

AP PROJECTION – CHEST &
ABDOMEN - Neonate

Florida Hospital protocol does not include chest/abdomen as 1 view