Positioning Flashcards
1
Q
What does Demonstrates mean?
A
- the anatomical structures on the projection are listed
2
Q
What does measure mean?
A
- the specific body area that is measured for calculating
exposure factors - central ray passes through here
3
Q
What is kVp?
A
- the optimum kilovolts peaks and range for the specific body part being imaged
4
Q
How to lower kVp?
A
increase frequency by 100 kHz lowers kVp by 10
5
Q
What kVp to use for cervicals?
A
80
6
Q
What kVp to use for Thoracic?
A
90
7
Q
What kVp to use for anteroposterior lumbar?
A
85
8
Q
What kVp to use for lateral lumbar?
A
90
9
Q
What kVp to use for HIP, pelvis, sacrum, coccyx?
A
80
10
Q
What kVp to use for Full spine?
A
90
11
Q
What kVp to use for knee?
A
60
12
Q
What kVp to use for extremities distal to bicep and knee?
A
55
13
Q
What kVp to use for clavicle and acromium?
A
70
14
Q
What kVp to use for shoulder?
A
75
15
Q
What kVp to use for ribs?
A
80
16
Q
What kVp to use for chest?
A
110
17
Q
What kVp to use for abdomen?
A
100
18
Q
What projections do not require a grid?
A
- Cervical: lateral, flexion/extension, oblique
- chest
19
Q
What is the minimum grid ratio?
A
10:1
20
Q
What is the Tube film Distance (Focal Film Distance)?
A
- distance between the tube and the film
21
Q
What are the possible Focal distances?
A
- traditional 105 cm
- some 160 - 200cm
22
Q
What is Tube Tilt?
A
- Angle of tube in relation to cephaled or caudad
- allows the central ray to pass parallel to a desired body part
23
Q
What is Patient Position?
A
- either standing, recumbent (lying down), sitting
24
Q
What are the advantage of doing a recumbent image?
A
- better anatomical detail
- smaller object film distances
- reduced scatter radiation
- less patient motion
25
What are the advantages of a standing (upright) image?
- shows the influence of gravity on bone alignment
| - important for screening of scoliosis, spondylolisthesis, osteoarthritis
26
Part Position?
- Position of the part being radiographed
| - ex. flexion extension, supination
27
What is the central ray?
- Center of the radiographic beam
| - determined by the cross marking from the colimator
28
What is Collimation?
- limits the film size but must collimate so that all body parts of interest are obtained in the radiograph
29
What is collimation important?
- reducing radiation dose
| - improving image quality
30
What are Clinical radio correlations?
- highlighting key anatomical features in ABC's format
31
What is the Clinical radio correlation ABC's format?
- A = alignment
- B = bone
- C = cartilage
- S = soft tissue
32
What are radiographic series?
- a set of radiographs on a specific body part
| - at least 2 images perpendicular to one another must be taken
33
What is a spot projection?
- isolated closely collimated view
| - reduces scatter radiation
34
What is skeletal survery?
- characterization of bone or joint lesion to confirm or exclude a diagnosis, gauge progress and assess severity of a lesion
35
What are the indication for a skeletal survey?
- bone dysplasia
- infection
- metastatic disease
- multiple myeloma
- non-accident injury
- pagets
- polyarthropathy (RA, Ankylosing spondy)
- metabolic diseases (renal bone disease, hyperparathyroidism, scurvy, rickets
36
What xrays are done in a skeletal survery?
- bilateral AP-PA hands, forarm, humerus, feet, legs, femur, pelvis
lateral spine and skull
37
What xrays are done in a joint survery?
- bilateral AP-PA hands and wrists, elbows, shoulder, feet and ankles, knees, hips, SIJ
- lateral spine
38
What is needed for film identification?
- patient's name
- date of exposure
- clinic taken
* legal requirement
39
What is the Bucky?
- housing an moving the grid
| - surface the patient contacts
40
What is a grid?
- lead strips separated by radiolucent material
| - eliminates scatter radiation
41
What is the tube used in a radiograph?
- x-rays are produced inside of this via bombarding anodes with high velocity electrons created at the cathode
- these xrays travel toward the patient through the window formed by the collimator
42
What is tube tilt?
- angle oft he beam is altered to better anatomical detail
| - for every 5 degrees of angulation the tube should be moved 2cm closer to the patient
43
What is that collimator?
- cube on the outside of the x-ray tube
| - can be used to reduce the are of emitted radiation
44
What is Kilovolts Peak (kVp)?
- the potential difference b/w cathode (filament) and anode during the exposure
- it represents the speed electrons have when they reach the anode = strength of the emitted rays = ability to penetrate body
- kVp is determinent of the image quality and alters the contrast of the film
- the thicker the part the greater kVp should be used
45
What are Milliampere Seconds (mAs)?
- # of electrons generated per second
- determines density
- doubling mAs doubles film density
46
What side is marked on oblique and lateral views?
- the side closest to the bucky
47
What is filtration?
- placement of aluminum at the collimator
| - reduces the xrays reaching patient, reducing exposure
48
What is Relative exposure?
- assessment of radiograph according to film darkness
- with optimal kVp:
too much mAs = dark film = overexposed
too little mAs = light film = underexposed
49
What is Object Density?
- black area = radiolucent
| - white area = radioopaque
