Technique Charts

Question 1

What are the three standardization phases for technique?

Answer 1

Standardization of projections
Standardization of exposure factors
Standardization of image process

Question 2

What is a standardization of projections?

Answer 2

Routine views used for a particular exam by hospital

Question 3

What is a standardization of exposure factors?

Answer 3

Technique charts that are created by the department

Question 4

What is a technique chart?

Answer 4

A guide to exposure factors for a particular part or region

Question 5

What must a technique chart include?

Answer 5

• name of the exam or part
• projection/position name
• ma, s, KV and SID
• part thickness
• IR speed/CR speed, grid/bucky ratio

Question 6

To develop a proper technique chart what should be included?

Answer 6

Input from all radiographers
Proper equipment callibration
Updates regularly (every 6 months)

Question 7

What is the most important reason to use a technique chart?

Answer 7

More consistent radiographic quality is achieved

Question 8

What are the two basic types of technique charts?

Answer 8

Fixed kVp with variable mAs or Variable kvp with fixed mAs

Question 9

What is the basis of fixed kVp - variable mAs charts?

Answer 9

Assumes optimal kVp for the part being radiographed

Question 10

When does kVp change in a fixed kvp chart?

Answer 10

Only for exceptionally large patients, but otherwise never

Question 11

What is the varied mAs based on in a fixed chart?

Answer 11

According to a part thicknes which is measured with calipers

Question 12

How are calipers used?

Answer 12

• Measure the thickness of a knee phantom
• Multiply that thickness by 2 and add 23

Question 13

How do caliper measurements need to be adjusted for single phase or three phase machines?

Answer 13

Add 30 or 35 respectively to get the kvp

Question 14

What is the 4 cm rule?

Answer 14

If the part thickness goes up by 4 cm you need to double the exposure (adjust kVp by 15% or double mAs)

Question 15

What is the basis of variable kVp- fixed mAs charts?

Answer 15

kVp is varied according to part thickness as measured with the calipers and mAs is kept the same for all patients

Question 16

What is the general KV rules for variable KV charts?

Answer 16

Adjust KV by 2 per centimeter thickness

Question 17

What is the base 60 approach to variable kVp?

Answer 17

The kVp is set to two times the measured part and then added to a based 60

Question 18

If a part measuring 13 cm, what would the kVp used be?

Answer 18

60 + (2 x 13)
60 + 26 = 86 kVp

Question 19

Which of the two technique charts is used more often?

Answer 19

Variable kVp- fixed mAs

Question 20

Which of the two technique chart methods yields higher kvp values?

Answer 20

Fixed kvp

Question 21

What is APR?

Answer 21

Automatically programmed radiography which is an electronic technique used for patient exposure control

Question 22

What does APR use?

Answer 22

Microprocessor technology

Question 23

How does a tech use an APR technique chart?

Answer 23

Rather than selecting a kvp or MAs they use graphics on a console to select the technique

Question 24

What is the proportional anatomy approach?

Answer 24

Basis that for a given body habitus a technique for one part can be derived from a known technique for another part

Question 25

What parts are included in Group 1 of the proportional anatomy groupings? (Avg 22 cm)

Answer 25

AP Abdomen - AP pelvis - AP lumbar spine - AP hip - Lateral hip - Townes Skull

Question 26

What parts are included in Group 2 of the proportional anatomy groupings? (Avg 13 cm)

Answer 26

- AP C-spine - All c-spines - AP Shoulder/clavicle/scapula - Lateral skull - AP/Lat femur - AP/PA Chest - AP Sacrum/Coccyx

Question 27

What parts are included in Group 3 of the proportional anatomy groupings? Barium

Answer 27

Solid/ air contrast - UGI AP = BE AP - UGI Obl = BE Obl - UGI Lat = BE Lat

Question 28

What parts are included in Group 4 of the proportional anatomy groupings? Extremities

Answer 28

AP Foot and AP Elbow - Lat Foot, Lat Ankle and AP humerus - AP leg, Lat leg and Lat humerus

Question 29

What factors will generally require changes to technique to achieve optimal images?

Answer 29

Body habitus Muscularity Age Molecular composition of tissues Contrast resolution Pathology Casts and splints

Question 30

If a patient is muscular, how will radiogrpahic technique need to be adjusted?

Answer 30

Generally higher than whats listed on a technique chart - Generally a 35-50% increase in kVp

Question 31

If a patien is older, how will radiographic technique need to be adjused?

Answer 31

Generally lower

Question 32

How should dose be adjusted for pediatric patients?

Answer 32

Generally it should be reduced with more attention to shielding and collimation

Question 33

What are the five tissue types that should be considered when setting technique?

Answer 33

Gas Fat Fluid Bone Metals

Question 34

What are the two types of contrast agents used in patients?

Answer 34

Positive and negative

Question 35

What are positive contrast?

Answer 35

Agent that is more absorbant and shows white on a radiograph

Question 36

What technique changes should be used for positive contrast agents?

Answer 36

kVp high, between 80-100 for iodine based contrasts and around 120 for barium

Question 37

What is negative contrast?

Answer 37

Agents are gases like air or carbon dioxide

Question 38

What technique should be used for exams with large amount of barium sulfate?

Answer 38

High KV (over 100) with appropriate MAs

Question 39

How should technique be adjusted for IVP exams?

Answer 39

A small amount of MAs increase is necessary with KVP below 75

Question 40

What are special considerations of technique charts?

Answer 40

Casts Pathological Conditions Age Body Mass Contrast media Grids OID