2c. Orbits & Mandible Bone Views and Positioning Flashcards
what are orbit xrays used for
to make sure there arent any metal foreign bodies in eyes before a MRI
what are the 2 views called for orbit imaging
OF 25-30 and lateral
what is the typical approach for orbit xrays
do a OF 25-30 and if a FB is seen on the projection, repeat OF view to confirm and then take a lateral
what is the central ray and centering point for OF 25-30 orbit view
horizontal ray centered in midline at level of midpoint of orbits
what is the positioning for lateral orbit view and wht is the difference from other lateral views of the head
same positioning as lateral facial bones but well collimated (smaller area of interest)
when are mandible projections taken
if an OPG machine is unavilable or a patient is not suitable for OPG
what are the 2 views we take for mandibles
PA and both obliques
what is the patient position for the PA mandible
in terms of sitting/standing, what is perp to IR, what to do with nose and head, OMBL
stand/sit facing erect bucky
place nose and forehead onto bucky
MSP perp to IR
adjust patient so OMBL is at 90* to IR
what is the central ray and centering point for PA mandible
Horizontal ray
centered in midline to exit at the junction of the lips
what is the collimation for a PA mandible
collimate to include condyles and symphysis
what are the exposure factors and SID for the PA mandible
70kV, 16mAs, 110cm SID
what side of the mandibles does the oblique view demonstrate
demonstrates the side closest to the IR
oblique mandible views must include what 3 things
TMJ of side viewed
skin surfaces of mandible
mandibular symphysis
what is the patient position for the oblique mandible
in terms of sitting/standing, what is placed on IR, what to do with neck, head tilt
patient standing/sitting next to upright bucky
place head in lateral position with side of interest against IR
extend neck
tilt head to about 10-15* (start in lateral and drop head 10-15*)
for the oblique mandible view why do we extend the neck
to clear the mandible of the c spine
what are the central ray for the mandible oblique view
CR angled 25* cranially
straight ray used in some centers
what is the centering point for oblique mandible view
center to angle of mandible
what are the exposure factors and SID for the oblique mandible view
70kV, 4-5mAs, 110 SID (no bucky?)
how do you achieve the head tilt if the patient is a trauma and has to do the oblique mandible view supine
head drop in toward IR by a few degrees and can use same angulation
what is the shunt view
ventriculoperitoneal shunt is used to relieve pressure on brain caused by accumulation of fluid
the view is primarily used to treat hydocephalus
what are the 3 paranasal sinus views
OM55* - maxillary and ethmoid
OF 20*
lateral
what is the centering point for the OM55 paranasal sinus view
center at root of nose
what is the patient position for the OM55 paranasal sinus view
in terms of mouth
mouth is open just before exposure to demonstrate sphenoid sinuses
what is the centering point for the OF20* paranasal sinus view
center at nasion
