What technical factors and positioning components should you double check when positioning for a townes view to ensure a good image?
Ensure that the top of the IR is not lower than the vertex of the skull.
Also the CR and the IR may not be aligned especially when angling 37 degrees.
Always double check that they are aligned.
If the IR is not aligned with your tuve for a Townes image, what would the image look like?
Your image may cut off the vertex of the skull and the image may appear light/noisy because of the AEC
What is a manual exposure technique for a lateral skull with a grid ?
Average technical 12 mAs @ 80 kV
Could uoui perform all cranial views using either the table bucky or the wall bucky?
Yes all views can be performed on either the table or wall bucky.
Would it be appropriate to perform sinus images using the table bucky?why or why not
No, the projections should only be performed upright to demonstrate air fluid levels
How would the exposure technique change from the caldwell skull posotion as compared to the caldwell sinuses position ?why
The technique would decrease for sinuses because you do not need to penetrate the bones of the skull to properly demonstrate the sinuses.
If you used a skull technique to image the sinuses, the sinuses would be too dark to properly critique.
For the images of the sinuses with the patient upright could you angle the tube instead of changing the patient position?
Optimally you would only want to adjust the patient's head and keep a horizontal ray to demonstrate fluid levels accurately.
If the patient was a trauma case and could only lie on their back what position could you perform to still be able to visualize air fluid levels in the sinuses
The lateral cross-table position would be the best view to demonstrate air fluid levels in this scenario. (Patient is supine with horizontal beam).
When imaging facial bones where should the petrous pyramids be demonstrated on the caldwell view
The petrous pyramids should be in the lower one third of the orbits(15° angle) or at the infraorbital margin (20° angle)
– depending on procedure required at the clinical site
Which bones are of special radigraphic interest for the facial bones series
Maxilla, zygoma, mandible
Two views are routinely performed for the orbits
Modified Caldwell and lateral view
Would you use a special cassette to perform radigraphic imaging of the orbits when querying a foreign object?Why or why not
You would use a specially cleaned cassette to ensure that there are no artifacts that could be misconstrued in the diagnosis of the image
With reference to the IR, how should the midsagittal plane be adjusted for the tangential view demonstrating an individual zygomatic arch?
from perpendicular, rotate 15° towards affected side and then tilt chin 15° towards central ray
What equipment options do many facilities have to visualize the mandible
What markers are important to have visualized on the lateral TMJ views
Markers are essential to indicate the patients mouth be open or closed for each image
What are your options for positioning oblique views of the mandible to accommodate
If the patient has a short neck or wide shoulders you could angle the patient's head and angle your tube to a total of 25 degrees instead of just angling the tube 25 degrees cephalad and having the patient's head lateral. Example: patient’s head is angled 15° and the tube is angled 10°
What is the central ray for the posterior projection 0 degree Caldwell of the mandible?
Perpendicular to the acanthion
The midsagittal plane should be rotated-----degrees from the lateral position to demonstrate the body of the mandible for the Axiolateral view.
what angle is used for the central ray of the aziolateral view of the mandible?
25 degrees cephald
How is the excursion of a condyle demonstrated on a Schuller's view
Open mouth-Out of the mandibular fossa
Close mouth-Inside the manidibular
What bony structures make up the TMJ
Mandibular fossa of the temperal bone
The condyle of the mandible
What part of the mandible is well demonstrated on a posteroanterior projection
A Schuller's view for the TM joints requires a tobe angle of
25-30 degrees caudad
The unaggected TMJ will be demonstrated inderior and anterior to the affected TMJ on the Schuller's view.
True or false
To demonstrate the symphysis of the mandible on the axiolateral view , the head should be turned---to bring the part parallel to the cassette
What type of fracture displacement is best demonstrated on a posteranterior projection of the mandible
Lateral and medial displacement
Why should the chin be extended when imaging the mandible in the oblique views?
The chin is extended to et the area of interest away from the c- spine
( not superimposed over c-spine)
Where will the petrous pyramids be demonstraed on a PA projection of the mandible?Where would they be demonstrated if the chin was tucked too far down ?
The pertrous pyramids should be demonstrated extirly in the orbit.
If chin tucked too far down they be projected above the orbits
What are the Schuller's images performed with the mouth closed closed and opened?
To view the TMJ open and closed for displacement (excursion) of TMJ
What is the central ray for the Townes view of TMJ's?
35 degrees caudad 3in above the nasion
To obtian 30 frontooccipital projection of the skull with the infraorbitomeatal line perpendicular to the table the central ray is directed
Which line view of the skull what are tow things your can critique to identify if there is rotaion or not
Lateral borders of the skull are superimposed
Sella turcica is in profile
Maxillary struts aare superimposed
On a lateral view of thekull the patient's midsagittal plane is-----to the IR and the coronal plane is -------to the IR
In regards to the morphology of the skull which shape presents with the pertous pyramids at an angle of 54 to the mdisagittal plane
Where is the dorsum sella seen on Townes's view of the skull?
Centered within the foramen magnum
For a 15 degree caldwell view of the cranial bones where would the pertrous pyramids be demonstrated
Lower 1\3 of orbits
What is the direction of the central ray for the reversed caldwell
15 cephalic entering the nasion
What projection is the caldwell position
15 Occipitalfrontal projection
Which projection/view that demonstrates the foramen magnum
The OML is at degrees to the cassette for the Townes projection
True or false
How many degrees are there between the OML and the IOML
OML is 30
IOML is 37
7 degree difference
For the lateral view of the cranium the interpupillary line is --- it the IR
What is the landmark line that should be perpendicular to the cassette for the water's view of the sinuses?
What patient position should a patient be in for imaging the sinuses and why
For air and fluid levels
Which projection/view best demonstrates the frontal sinuses
15 occipitofrontal procjection Caldwell
What is the central ray for the lateral view of the facial bones
Perpendicular to lateral surface of upper zygoma
1\2 way between outer canthus and EAM
For the 15 occipitofrontal projection the petrous pyramids shoudl be demonstrated with in the lower maxillary sinuses
True or false
The parietaoacanthial projection will best demonstrate the
maxilla and orbits
The ---(OML/IOML)forms an angle of ---with the bucky for the waters view
For the reverse waters ofo the facial bones describe the central ray if the mentomeatal line cannot be extended enough to be perpendicular to the IR
The central ray becomes parallel to the mentomeatal line
The mentomeatal line is perpendicular to the IR for the Parietoacanthial projection(Transoral) of the sinuse
True or false
If the skull is under extended during imaging of the sinuses for the Parietoacanthial projection where will the petrous pyramids be projected
The petrousl pyramids will be projected in the maxillary sinuses
The long narrow head is termed
For the Dolicocephalic the petrous pyramids forms and angle of ---to the ---plane of the skull
Which image best demonstrates the nasal septum
What are the two structures of interest shown on the waters view of the sinuses
State the central ray for the lateral view of the sinuses
Perpendicular to 1\2 to 1in poterior from the outer canthus
On a townes view the zygomatic arches are projected laterally to the mandibular rami
true or false
A displacement fracture of the nasal septum would be best demonstraed on an
What reduction in exposure technique is required for a townes view of the zygomatic arches
Name three ways in which the radigrapher can ensure optimum detail for images of the orbits
1 Small focal spot
2 Close OID
3 Long SID
4 Patient very still
5 Clean IR
6 Good positioning
Which projection \ view will best demonstrate a depressed fracture of the zygomatic arches
Infersuperior projection(tangential view )
What is the best exposure technique to use for a lateral view of the nasal bone
A finger technique is best used for the nasal bones
When performing a tangential view of the zygomatic arches state whether the statement is True or false
-----The midsagittal plane is not perpendicular to the bucky
-----The coronal plane is parallel to the bucky
To determine if a foregn body is either superficail or deeply lodged in an eye the patient should look side to side for the ---view and look up and down for the --view
Modified caldwell/waters modified
Specifically name two structures of the orbits that are demonstraed on the modified caldwell view
Lesser and greater wing of the sphenoid
Superior margin of the orbits(orbit rims)
Where should the petrous pyramids be demonstrated on the modified parietoacanthial projection of the orbits
The pertrousl pyramids should be demonstrated within the maxillary sinuses
What are the routine projections/views for thenasal bones
whay would MRI not be used to determine if teh eye had a foreign body
MRI would not be used because the foreign body might contian metal and cause hemorrhage
What degree and gangle is the central ray for the modifed caldwell view of the orbits
20 to 30 degrees caudad
What projection is the Tangential view of the zygomatic arch
Name one projection/view that is performed as a bilateral study of the zygomatic arches