Positioning for skull Flashcards
1
Q
routine skull protocol
A
- Caldwell ( PA 15 degree axial)
- Towne ( AP 30 degree axial)
- Lateral (right or left) **
** still most common to do a left lateral
- field size is always 24x30 to start
- SID is always 110cm
2
Q
Caldwell (PA 15 degree axial) for skull
A
- 24x30 lightfield, 110 SID, turn on tracking
- angle tube 15 degrees caudad, put marker in either top corner
- with pt sitting on stool, have them stick their forehead and nose against the detector
- line up EAM to outer canthus (perpendicular to IR), that’s how to position the head. OML (the corner of the eyelid in line with EAM)
- side to side: finger width of light on either side and equal light on either side
- top of light: have finger width of light above vertex (that when you put your hand on top of their head there is light on your hand)
- bottom of light: finger width of light below mastoid tip
- put hand on either side of their face to make sure there is no tilt or rotation and that their EAMS are equal distance from the detector
- (-) at the naisson (bridge of nose)
- shield pt with the shielding covering their bum
- hold breath
*** reverse Caldwell exactly the same except done AP on the table and angling the tube 15 degrees CEPHALAD
3
Q
AP towne for skull
A
- 24x30 lightfield, 110 SID
- angle tube 30 degrees caudad (at the 60 mark, because starting from 90)
- even if the detector says 120 for SID as long as you are in the 110 lock ignore it. it just says that because of steep angle on the tube
- put small sponge behind pts head starting by slightly above the EAM
- (-) to start at the hairline, but can go abit higher
- side to side: equal light on either side of the skull, finger with of light on all sides
- top of light: aboout 1 finger above vertex
- bottom of light: 1 finger below mastoid tip
- position head so that EAM is in line with outer canthus which is the corner of the eyelid (OML)
- (I) centered on MSP
- won’t have light on eyes
- pt sitting on stool, facing you, line up tube and detector
- could be done on the table
- hold your breath
- marker in bottom corner
if pt is not comfortable doing OML you can add aan extra 7 degrees to tube angle. then for head position you would do to IOML instead (EAM in line with the eye bag area)
4
Q
left lateral for skull
A
- 30x24 lightfield, 110 SID
- pt sitting on stool, have them rotate shoulders and body in enough so that side of head and ear can touch the detector
- (I) two inches above and in line with the EAM
- if pt cant hold still then can put sponge between them and the detector
- top of light: about 1 finger above vertex
- bottom of light: finger of light below mastoid tip
- marker: anterior top lateral
- its okay to clip the nose
- want to see both sides of face evenly and not left side squished against the detector
- want pts face looking right at you (thats how you know there is no rotation and tilt)
- balance light on all sides, about a finger width on all sides
- head position: IOML
- line up tube and detector
- hold breath
5
Q
(left) lateral crosstable for skull
A
- 100 SID (use measuring tape to get distance from tube to cassette)
- 30x24 lightfied, cassette landscape
- put a square sponge under the pts neck and make sure they are nice and straight and even
- make sure cassette is resting on top of matress, with the casette right against the pts face and pushed down into their shoulder and secure it with two sandbags
- pt lying on their back
- (-) crosshair running right above the EAM
- use purple lock, then black lock to get into cross table position
- want (I) crosshair in line with the center notch on the cassette
- want light on the sponge (like 2-3 fingers) and a little above the top of head
- center about 2 inches above EAM
- go to the head of the table to make sure they are straight and not tilted or rotated
- marker in top anterior at a slant
- hold breath
- head positioned for IOML