Patient Positioning *final, not on midterm

Question 1

beam direction

Answer 1

first letter = where beam entered body
second letter = where it exited

D: dorsal
V: ventral
L: lateral
M: medial
L/Le: left
R/Rt: right
Cr: cranial
Cd: caudal
R: rostral
Pa, P: palmar
Pl, P: plantar
O: oblique
Di: distal
Pr: proximal

can also be combined to describe oblique views
eg. DMPaLO = dorso medial palmaro lateral oblique
- the bean entered DM surface, exited PaLO surface

MLO: medial lateral oblique
LO: lateral oblique

Question 2

basic criteria

Answer 2

1) welfare of patient
2) restraint + immobilization of patient
3) minimal trauma to area
4) least risk of radiation to restrainers

Question 3

patient preparation

Answer 3

wet fur or fur full of debris can appear
collars/harnesses will show up (esp if metal) so remove

use a calliper to measure area’s thickest part

Question 4

positioning aids

Answer 4

• sandbags, foam blocks, wood blocks, radiolucent troughs
• tape, gauze, rope, compression bands
• not under/over area… not completely non-radio opaque
• foam produces air density shadow + absorbs and retains liquids that might be radio-opaque when dry

Question 5

required views

Answer 5

• min 2 views at right angles of each other
• have area of interest closest to film -> reduces distortion and magnification of area under examination

Question 6

splitting cassettes

Answer 6

‘split’ film w/multiple views to minimize # of films per patient
- place sheet of lead over half of the film to stop its exposure, then put on the other half
- only done on table top, only with film
- make sure animal is positioned so all views of the area are facing the same direction on the film

Question 7

collimation

Answer 7

smallest field size possible
- larger area = more scatter radiation, decreased contrast

Question 8

x-ray positioning

Answer 8

• beam centered directly over area
• specific anatomy must be included for each anatomic area:
• long bone RGs need to include shaft + proximal and distal joints
• joint RGs should include portion of long bones distal + proximal

Question 9

film labeling

Answer 9

1) owner + patient
2) date
3) name + location of facility
4) vet
5) positioning markers

Question 10

markers

Answer 10

• marker for craniocaudal or caudocranial view should be placed on lateral aspect
• in DV or VD view marker should be placed on the cassette to identify one side or the other
• when a lateral projection of thorax/abdomen is taken, marker should indicate the side that is down on cassette
• when a lateral projection of an extremity is taken the marker should be placed cranially (or dorsally) to the leg (if both legs in same RG, use the marker of leg in contact w/ cassette/downside)
• mark sequential RGs w/ numbers that identify time elapsed or order taken

Question 11

viewing RGs

Answer 11

positions RGs for vet to view as follows:
- LAT: cranial part of animal to your left
- DV/VD: cranial part of animal points up
- OBL: proximal part of limb points up, cranial/dorsal aspect to your left
- DP/PD/CrCD/CdCr: proximal end of extremity points up